About IWMI: The Interna}onal Water Management Ins}tute (IWMI) is an interna}onal, research-for development organiza}on that works with governments, civil society, and the private sector to solve water problems in developing countries and scale up solu}ons. Through the partnership, IWMI combines research on the sustainable use of water and land resources, knowledge services, and products with capacity strengthening, dialogue, and policy analysis to support the implementa}on of water management solu}ons for agriculture, ecosystems, climate change, and inclusive economic growth. Headquartered in Colombo, Sri Lanka, IWMI is a CGIAR Research Center with oïces in 14 countries and a global network of scien}sts opera}ng in more than 30 countries. About CGIAR: CGIAR is a global research partnership for a food-secure future. CGIAR science is dedicated to transforming food, land and water systems in a climate crisis. Its research is carried out by 13 CGIAR Centers/Alliances in close collabora}on with hundreds of partners, including na}onal and regional research ins}tutes, civil society organiza}ons, academia, development organiza}ons and the private sector. www.cgiar.org About SoLAR: Solar Irriga}on for Agricultural Resilience (SoLAR) in South Asia aims to sustainably manage the water-energy and climate interlinkages in South Asia through the promo}on of solar irriga}on pumps (SIPs). The project9s main goal is to contribute to climate-resilient, gender-equitable, and socially inclusive agrarian livelihoods in Bangladesh, India, Nepal, and Pakistan by suppor}ng government eforts to promote solar irriga}on. This project responds to government commitments to transi}on to clean energy pathways in agriculture. All countries in this project have NDC commitments to reduce greenhouse gas (GHG) emissions, and SIPs can play a signiocant role in reducing emissions in agriculture. About SDC: The Swiss Agency for Development and Coopera}on (SDC) is the agency for interna}onal coopera}on of the Federal Department of Foreign Afairs (FDFA). Swiss Interna}onal Coopera}on, an integral part of the Federal Council9s foreign policy, aims to contribute to a world without poverty and in peace for sustainable development. SDC, through its Global Program Climate Change and Environment (GPCCE), helps ond solu}ons to global challenges linked to climate change. It engages in global poli}cal dialogue and manages specioc projects in the oelds of energy, climate change adapta}on, sustainable development of mountainous regions, and preven}on of natural hazards that are likely to innuence regional and interna}onal policy. Authors: Shisher Shrestha is a Na}onal Researcher - Renewable Energy, Water, and Climate Change at IWMI Nepal; Labisha Uprety is a Senior Research Oïcer - Policy and Water Governance at IWMI Nepal; Kushal Gautam is a Solar irriga}on expert at Quasar Energy Consultants, Nepal. Shrestha, S.; Uprety, L.; Gautam, K. 2023. Training Manual on Solar Irriga}on Pumps. Colombo, Sri Lanka: Interna}onal Water Management Ins}tute (IWMI). 133p. Disclaimer: This publica}on has been prepared with care. Responsibility for edi}ng, proofreading, and layout, opinions expressed and any possible errors lies with the authors and not the ins}tu}ons involved. The boundaries and names shown and the designa}ons used on maps do not imply oïcial endorsement or acceptance by IWMI, CGIAR, our partner ins}tu}ons, or donors. Copyright © 2023, by IWMI. All rights reserved. IWMI encourages the use of its material provided that the organiza}on is acknowledged and kept informed in all such instances. Please send inquiries and comments to iwmi-solar@cgiar.org A free copy of this publica}on can be downloaded at htps://solar.iwmi.org/reports/ Acknowledgments This Training Manual on Solar Irriga}on Pumps is a part of the Solar Irriga}on for Agricultural Resilience (SoLAR) project supported by the Swiss Agency for Development and Coopera}on (SDC). We sincerely appreciate the Alterna}ve Energy Promo}on Centre (AEPC), who has been a key partner in the SoLAR-SA project in Nepal, for their unwavering support throughout the project's execu}on. We value the contribu}ons of Mr. Khirendra Yadav from the Pathibhara Polytechnic Ins}tute and Mr. Bipin Lamichhane from Quasar Energy Consultants for their assistance in crea}ng the drav edi}on of the manual. We thank Equal Access for helping with the transla}on of the manual into Nepali and the crea}on of a bilingual edi}on of the manual. We also acknowledge Mr. Aariz Raza of IWMI New Delhi for his assistance in manual's design. Donor Swiss Agency for Development and Coopera}on (SDC) Partner Alterna}ve Energy Promo}on Center (AEPC) Training manual on Solar Irrigation Pumps | Abbreviations AC Alternating Current DC Direct Current I Maximum Power Point Current MP I Short Circuit Current SC Mono-SI Monocrystalline Silicon MPPT Maximum Power Point Tracking P Maximum Power MAX Poly-SI Polycrystalline Silicon PWM Pulse Width Modulation PV Photovoltaic SIP Solar Irrigation Pumps SWP Solar Water Pumps V Voltage V Maximum Power Point Voltage MP V Open Circuit Voltage OC O & M Operation & Maintenance Wp Watt-peak Author Mr. Shisher Shrestha, International Water Management Institute Mrs.. Labisha Uprety, International Water Management Institute Mr. Kushal Gautam, Quasar Energy Consultants Acknowledgements Mr. Khirendra Yadav, Pathibhara Polytechnic Preparation of the first draft Mr. Bipin Lamichhane, Quasar Energy Consultants Proof-read and supported in draft preparation | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;+lIfKt ?k P;L cN6/g]l6+u s/]G6 l8;L 8fO/]S6 s/]G6 cfO{PdkL d}lS;dd\\ kfj/ KjfOG6 cfO{P;;L z6{ ;ls{6 s/]G6 df]gf]3P;cfO{ df]gf]lqmli6lng l;lnsg\\\ PdkLkL6L d}lS;dd\\ kfj/ KjfOG6 6«oflsª\u kLDofS; d}lS;dd\\ kfj/ kf]nL3P;cfO{ kf]lnlqmli6lng l;lnsg\\ kL8ANo"Pd kN; lj8\y df]8\o'n]zg lkeL kmf]6f]ef]N6flos ;f}o{ kDk ;f}o{ Ol/u]zg kDk P;8ANo"kL ;f}o{ jf6/ kDk eL ef]N6]h eLPdkL d}lS;dd\\ kfj/ KjfOG6 ef]N6]h eLcf];L cf]kg ;ls{6 ef]N6]h cf] P08 Pd ;~rfng / dd{t ;Def/ 8ANo"kL jf63kLs n]vs >L lzlz/ >]i7, cGt/f{li6«o hn Joj:yfkg ;+:yf >L nlazf pk|]tL, cGt/f{li6«o hn Joj:yfkg ;+:yf >L s'zn uf}td, Sj]hf/ OghL{ sG;n6]G6\; s[t1tf kflyef/f kf]ln6]lSgs klxnf] d:of}bfsf] tof/L >L lalkg nfld5fg], Sjh] f/ OghL { sG;n6G] 6;\ d:of}bf tof/ ug{ k|"km l/8 / ;xof]u k|bfg Training manual on Solar Irrigation Pumps | Table of Contents ljifo ;"rL Section I: Introduction to Solar PV System v08 !M ;f}o{ lkeL k|0ffnLsf] kl/ro 1. Introduction ...........................................................................................................................................12 != kl/ro Advantages of o-grid solar PV systems ................................................................................................................... 12 ckm3lu|8 ;f}o{ lkeL k|0ffnLsf kmfObfx? Clean Energy ......................................................................................................................................................... 14 :jR5 ;kmf pmhf{ -lSng OghL{_ Reliability ............................................................................................................................................................... 14 ljZj;gLotf Reduced Operating Costs .................................................................................................................................... 14 sd ;~rfng nfut No Sound Pollution .............................................................................................................................................. 14 Wjlg k|b"if0f x'Gg Modularity ............................................................................................................................................................. 14 k|lt?kstf Sustainable Energy ................................................................................................................................................ 14 lbuf] pmhf{ Limitations of o-grid solar PV systems .................................................................................................................... 16 ckm3lu|8 ;f}o{ lkeL k|0ffnLsf] s]lx sldx? High Initial Cost .................................................................................................................................................... 16 ;'?df nfut pRr Relatively large footprint ...................................................................................................................................... 16 t'ngfTds ?kdf 7fpF w]/} rflxG5 Need of Energy Storage Devices ........................................................................................................................ 16 pmhf{ e08f/0fsf nflu pks/0fsf] cfjZostf Inconsistent Source of Energy ............................................................................................................................. 16 clgoldt phf{ ;|f]t Lack of Awareness ............................................................................................................................................... 16 r]tgfsf] sdL Solar PV Applications .................................................................................................................................................. 18 ;f}o{ lkeLsf] pkof]u Lighting System for Home .................................................................................................................................... 18 3/sf nflu ljB'tLo k|0ffnL | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Television and Radio ............................................................................................................................................. 18 6]lnlehg / /]l8of] Water Pumping ..................................................................................................................................................... 18 kfgL tfGg] oGq Street Light ............................................................................................................................................................ 18 ;8s aQL 2. Electrical demand load analysis ...........................................................................................................20 @= lah'nL dfusf] nf]8 ljZn]if0f Ecient Energy Utilization .......................................................................................................................................... 20 pmhf{sf] k|efjsf/L pkof]u Electrical Load Analysis ............................................................................................................................................... 20 ljB'tLo nf]8 ljZn]if0f Load estimation ........................................................................................................................................................... 20 nf]8 cg'dfg Consideration in load estimation ......................................................................................................................... 22 nf]8 cg'dfgdf Wofg lbg'kg]{ a'Fbfx? Cable Size .................................................................................................................................................................... 22 s]an ;fOh 3. Solar PV System Component ..............................................................................................................24 #= ;f}o{ lkeL k|0ffnLsf] sDkf]g]G6 Solar PV module .......................................................................................................................................................... 26 ;f}o{ lkeL Kofgn Types of solar module ................................................................................................................................................ 26 ;f}o{ Kofgnsf] k|sf/x? Rated output specifications and solar panels ............................................................................................................. 32 dfqfltt pTkfbg lglb{li6s/0f / ;f}o{ Kofgn Array Sizing .................................................................................................................................................................. 36 P/]sf] ;fOlhª Batteries ....................................................................................................................................................................... 40 Aof6«Lx? Types and operation of a battery ............................................................................................................................... 40 Aof6«Lsf] k|sf/ / ;~rfng Flooded Lead Acid Battery .................................................................................................................................. 40 Æn8]8 ln8 Pl;8 Aof6«L Training manual on Solar Irrigation Pumps | VLRA battery ........................................................................................................................................................ 42 eLPncf/P Aof6«L AGM battery ......................................................................................................................................................... 42 PhLPd Aof6«L Nickel-Cadmium Batteries ................................................................................................................................... 42 lgs]n Sof8ldod Aof6«L Lithium-ion batteries ............................................................................................................................................ 42 lnlyod3cfof]g Aof6«L Battery bank sizing and Calculations .......................................................................................................................... 42 Aof6«L a}+s ;fOlhª / u0fgf Battery Cable Connections ........................................................................................................................................ 46 Aof6«Lsf] tf/ h8fg Series Connection ................................................................................................................................................ 48 ;L/Lh h8fg Parallel Connection............................................................................................................................................... 48 Kof/fnn h8fg Series / Parallel Connection ................................................................................................................................ 50 ;L/Lh÷;dfgfGt/ h8fg Specification .......................................................................................................................................................... 50 lglb{li6s/0f Example of battery specification .......................................................................................................................... 52 Aof6«L lglb{li6s/0f -:k]l;lkms]zg_ sf pbfx/0fx? Charge Controller ....................................................................................................................................................... 52 rfh{ sG6«f]n/ Types of Charge Controller ....................................................................................................................................... 56 rfh{ sG6«f]n/sf] k|sf/x? Non-MPPT Charge Controller ............................................................................................................................ 56 u}/3PdkLkL6L rfh{ sG6«f]n/ -PdkLkL6L gePsf]_ MPPT Charge Controller ..................................................................................................................................... 56 PdkLkL6L rfh{ sG6«f]n/ Charge Controller Features ................................................................................................................................. 56 rfh{ sG6«f]n/sf ljz]iftfx? Specification of Charge Controller ...................................................................................................................... 58 rfh{ sG6«f]n/sf] lglb{li6s/0f | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Sizing a Charge Controller .......................................................................................................................................... 60 rfh{ sG6«f]n/sf] ;fOlhª Inverter ........................................................................................................................................................................ 62 OGe6{/ Types of Inverters ....................................................................................................................................................... 62 OGe6{/sf k|sf/x? O-Grid Inverter .................................................................................................................................................. 62 ckm3lu|8 OGe6{/ Hybrid inverter ..................................................................................................................................................... 62 xfOla|8 OGe6{/ Grid-tied inverter.................................................................................................................................................. 64 lu|836fO8 OGe6{/ Inverter Sizing .............................................................................................................................................................. 66 OGe6{/sf] ;fOlhª Specification of an inverter ......................................................................................................................................... 66 OGe6{/sf] lglb{li6s/0f Section II: Solar Irrigation Pump v08 @M ;f}o{ l;+rfO kDk 4. Introduction ...........................................................................................................................................72 $= kl/ro 5. Basic Steps in System Design ..............................................................................................................74 %= l;:6d l8hfOgsf] cfwf/e"t r/0fx? General Head Calculation ......................................................................................................................................... 74 ;fwf/0f x]8 u0fgf Choice of Pump ......................................................................................................................................................... 76 kDksf] 5gf]6 General Overview of SIPs Installation ...................................................................................................................... 78 ;f}o{ kDk h8fgsf] ;fdfGo kl/b[Zo Site selection ......................................................................................................................................................... 78 ;fO6 ;]n]S;g SIP Installation ....................................................................................................................................................... 80 ;f}o{ kDk h8fg Training manual on Solar Irrigation Pumps | 6. Annex: Installation Report Template .................................................................................................86 ^= cg';"rLM h8fg l/kf]6{sf] gd"gf Section III: Operation and Maintenance of SIPs v08 #M ;f}o{ kDksf] ;~rfng / dd{t 7. Routine Maintenance and Preventive Maintenance .......................................................................94 &= lgoldt dd{t;Def/ / lg/f]ws dd{t;Def/ PV Array ..................................................................................................................................................................... 94 lkeL P/] Pump ........................................................................................................................................................................... 96 kDk Controller box ........................................................................................................................................................... 96 sG6«f]n/ aS; Cables ......................................................................................................................................................................... 98 tf/x? Protection and other components ........................................................................................................................... 100 ;+/If0f / cGo sDkf]g]G6x? 8. Failure and Troubleshooting ............................................................................................................102 *= ;d:of / ;d:ofsf] lgjf/0f Type 1 ........................................................................................................................................................................ 102 klxnf] k|sf/ Problems in the fuses and miniature circuit-breakers ........................................................................................ 102 km\o'h / Pd;LaL -ldlgPr/ ;ls{6 a|]s/_ df ;d:of Faulty panel or panel wiring ................................................................................................................................ 104 Kofgndf v/faL jf s]andf ;d:of Faulty controller ................................................................................................................................................... 106 sG6«f]n/df v/faL Faulty pump ......................................................................................................................................................... 108 kDkdf v/faL Faulty cable between controller and pump ........................................................................................................ 110 sG6«f]n/ / kDk aLrsf] s]a'ndf v/faL Faulty fuses or circuit-breakers ........................................................................................................................... 110 km\o'hx? jf ;ls{63a|]s/df v/faL Type 2 ........................................................................................................................................................................ 112 k|sf/ @ | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Inadequate power generation from the solar array ........................................................................................... 112 ;f}o{ P/]af6 ckof{Kt pmhf{ pTkfbg Issues with power regulation by the controller .................................................................................................. 112 sG6«f]n/sf] pmhf{ lgodg;Fu ;DalGwt ;d:ofx? Issues with pump operation ................................................................................................................................ 114 kDk ;~rfng;Fu ;DalGwt ;d:ofx? 9. Electrical Testing ..................................................................................................................................116 (= ljB'tLo k/LIf0f Array open circuit voltage ................................................................................................................................... 116 P/]sf] v'nf ;ls{6 ef]N6]h Voltage under load (with running pump) ............................................................................................................ 116 nf]8 cGtu{t ef]N6]h -kDk ;~rfngdf /xFbf_ Test the float switch ............................................................................................................................................. 118 Ænf]6 :jLrsf] k/LIf0f Do this only for testing purposes. ...................................................................................................................... 118 of] k/LIf0f p2]Zosf nflu dfq} ug'{xf];\ 10. Dos and Don’ts for Basic Maintenance ...........................................................................................120 !)= cfwf/e"t -;fdfGo_ dd{tsf nflu ug{ x'g] jf gx'g] sfdx? 1. Annex: O&M template .....................................................................................................................124 cg';"rLM ;~rfng / dd{t ;+ef/ 6]DKn]6 11. References .........................................................................................................................................132 ;fGble{s ;|f]tx? Training manual on Solar Irrigation Pumps | Section I: Introduction to Solar PV System 10 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf v08 !M ;f}o{ lkeL k|0ffnLsf] kl/ro 11 Training manual on Solar Irrigation Pumps | 1. Introduction Energy continues to be a major building block of modern civilizations. Among the many existing technologies and sources of energy, there is now a pronounced interest in the promotion of renewable energy technologies that depend on nature for harvesting energy. These technologies are seen to be cleaner, and more sustainable than those depending on fossil fuels in particular. The photovoltaic (PV) system among other renewable technologies is becoming increasingly common; these systems are devices that convert sunlight to electrical energy. As a country that receives abundant sunlight with average solar radiation of 4.4 kWh/m2 to 5.5 kWh/m2 and around 300 sunny days per year (Solargis, 2019), Nepal has an excellent potential to be able to harvest this energy using a solar photovoltaic system. Figure 1 Photovoltaic Electricity Potential of Nepal (Solargis, 2021) Advantages of o-grid solar PV systems O-grid solar PV systems can be an ideal solution to cover basic and advanced energy needs. Basic needs can include lighting, mobile charging, etc. whereas, advanced needs can include o-setting industry-level grid electricity with proper cost-benefit analyses. Photovoltaic systems have numerous advantages, especially in comparison with conventional fossil fuels. 12 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf != kl/ro pmhf{ cfw'lgs lgdf{0fsf] k|d'v cfwf/ x'g] qmd hf/L 5 . cg]sf}+ ljBdfg k|ljlwx? / pmhf{ ;|f]tx?dWo] k|s[ltdf cfwfl/tg jLs/0fLo pmhf{ k|ljlwx?sf] k|j4{gdf ca a9L rf;f] lbg yflnPsf] 5 . ljz]iftM hLjfz]ifdf cfwfl/t OGwgx?df lge{/ /xg] eGbf oL k|ljlwx? a9L ;kmf / clws lbuf]] b]lvPsf 5g\ . kmf]6f]ef]N6flos -lkeL_ k|0ffnL cGo gjLs/0fLo k|ljlwx?eGbf cfd ?kdf k|of]u x'Fb} uPsf] 5 . lkeL -kmf]6f]ef]N6flos_ k|0ffnLdf ;"o{sf] ls/0fnfO{ ljB'tLo pmhf{df ?kfGt/0f ug]{ pks/0f hl8tx 'G5g\ . g]kfndf k|lt ju{ ld6/ If]qdf Ps 306fdf cf};t $=$ lsnf]jf6 b]lv %=% lsnf]jf6 ;f}o{ ljls/0f k|fKt x'G5 ;fy} jif{df ;/b/ tLg ;o lbg g} k|r'/ dfqfdf ;"o{sf] k|sfz k|fKt x'g] x'Fbf oxfF ;f}o{ k|0ffnL k|of]u u/L pmhf{ ;Íng ug{ ;Sg] w]/} ;Defjgf 5 . tl:j/ ! g]kfnsf] kmf]6f]ef]N6flos ljB'tsf] ;DefJotf -;f]nf/ hLcfOP;\, @)@!_ ckm3lu|8 ;f}o{ lkeL k|0ffnLsf kmfObfx? ckm3lu|8 ;f}o{ lkeL k0| ffnL -alQ gku' s] f ] 7fpxF ?df jf dg] nfOgdf ghfl] 8Psf_] cfwf/et" / pRr pmhf{ cfjZostfx? k"/f ug{sf nflu Ps cfbz{ ;dfwfg x'g ;S5 . cfwf/e"tc fjZostf cGt{ut\ aQL afNg', df]afOn rfh{ ug'{ cflbnfO{ lng ;lsG5 . hasL, pBf]u :t/sf] pGgt÷pRr cfjZostfx?dfp lrt nfut nfe ljZn]if0f;lxtsf] lu|8 ljB'tsf] lgof{t 36fpg ;lsG5 . ljz]if u/L k/Dk/fut\ hLjfz]ifdf cfwfl/t OGwgsf] t'ngfdf kmf]6f]ef]N6flos k|0ffnLsf] w]/} kmfObfx? 5g\ . 13 Training manual on Solar Irrigation Pumps | Clean Energy PV systems help reduce CO and other harmful emissions and pollutants into the atmosphere and improve 2 public health and the environment. Reliability The life of PV systems is expected to be about 25 years and they can be installed in various regions and climates where exposure to the sun is optimal. It is a proven technology with decades of global success history. Reduced Operating Costs PV systems depend on sunlight for energy conversion and do not require any external fuel resulting in fuel cost savings. Compared to diesel-fuelled generators, solar PV systems require minimum maintenance. No Sound Pollution Unlike generators and other sources of power and their generating system, PV does not contribute to sound pollution. Modularity PV systems are modular, meaning their capacity can be expanded as required to increase power generation. Its components are individually replaceable in case of failure (for eg. individual solar modules, inverters, batteries, etc.) Sustainable Energy Solar PV systems use solar radiation to generate electricity which is amongst the most sustainable renewable energy source as it is naturally found and will not be aected by market factors such as, changes in the fuel markets. 14 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf :jR5 ;kmf pmhf{ -lSng OghL{_ lkeL k|0ffnLn] jftfj/0fdf sfa{g8fOcS;fO8 36fpg d2t k'of{pF5 / cGo xflgsf/s pT;h{g tyf k|b"ifsnfO{ sd ug{ / hg:jf:Yo Pjd\ jftfj/0f ;'wf/ ug{ ;xof]u k'of{pF5 . ljZj;gLotf lkeL k|0ffnLsf] cfo" sl/a @% jif{ x'g] ck]Iff ul/Psf] 5 / ;f}o{ ls/0fsf] clwsQd kx'Fr tyf w]/} 3fd nfUg] If]q tyf df};ddf of] h8fg ug{ ;lsG5 . of] bzsf}+sf] ljZjAofkL ;kmn Oltxf;sf] Ps k|dfl0ft k|ljlw xf] . sd ;~rfng nfut pmhf{ ?kfGt/0fsf nflu lkeL k|0ffnL ;"o{sf] ls/0fdf lge{/ x'G5 / s'g} klg afXo OGwg cfjZos gkg]{ x'gfn] OGwgsf] nfut art x'G5 . ;f}o{ lkeL k|0ffnLnfO{ l8h]n h]g]/]6/x?sf] t'ngfdf Go"gQd dd{t cfjZos k5{ . Wjlg k|b"if0f x'Gg h]g]/]6/x? / kfj/sf cGo ;|f]tx? tyf ltgLx?sf] pTkfbg k|0ffnLsf] ljkl/t lkeL k|0ffnLn] Wjlg k|b"if0fdf of]ubfg ub}{g . k|lt?kstf lkeL k|0ffnL k|lt?ks x'G5, cyf{t\ ljB't pTkfbg j[l4 ug{ cfjZostf cg';f/ ltgLx?sf] Ifdtf la:tf/ ug{ ;lsg] vfnsf] x''G5 . of] k|0ffnL sfd gnfUg] ePsf] cj:yfdf klg o;sf ;f}o{ Kofgn, OGe6{/, Aof6«L cflb cGo sfddf k|of]u ug{ ;lsG5 . lbuf]] pmhf{ ;f}o{ lkeL k|0ffnLx?n] ljB't pTkfbg ug{ ;f}o{ ljls/0fsf] k|of]u u5{ h'g ;a}eGbf lbuf]] gjLs/0fLo pmhf{ dWosf] Ps xf] . ;|f]tsf] ?kdf of] k|fs[lts ?kn] pknAw x'G5 / OGwgsf] ahf/df cfpg] kl/jt{g h:tf sf/0fn] o;df k|efj kb}{g . 15 Training manual on Solar Irrigation Pumps | Limitations of o-grid solar PV systems Although the advantages of o-grid solar PV systems are becoming more apparent, they do possess some limitations that should be considered. High Initial Cost PV systems require high initial investment than those of conventional power sources. The PV system produces DC power which demands additional equipment to convert the DC power into AC to run AC loads. Relatively large footprint The PV system installation requires a comparatively large footprint (compared to diesel generators for example), which may not always be available on the ground or roofs. Need for Energy Storage Devices For 24-hr energy demand, sunlight is not always available and even when it is available, it is not constant. This requires energy storage, such as batteries, to provide a consistent and reliable power supply. The batteries and other storage devices increase the cost of the system. Inconsistent Source of Energy Sunshine is not always available even in the daytime. Geographic location, climate, and other environmental conditions aect the amount of sunlight exposure. Lack of Awareness People are generally unaware of the advantages of solar PV technology and its applications as it is fairly new compared to other fossil fuel-based technologies, and its adoption remains expensive and slow. 16 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ckm3lu|8 ;f}o{ lkeL k|0ffnLsf] s]lx sldx? ckm3lu|8 ;f}o{ k|0ffnLsf kmfObfx? w]/} eP klg o;sf s]xL sldx?af/] ;d]t ljrf/ ug'{kg]{ x'G5 . ;'?df nfut pRr kf/Dkl/s pmhf{ ;|f]tx?sf] t'ngfdf lkeL k|0ffnLnfO{ ;'?df w]/} nufgL cfjZos x'G5 . lkeL k|0ffnLn] l8;L kfj/ pTkfbg u5{ h;n] P;L nf]8 rnfpg l8;L kfj/nfO{ P;Ldf ?kfGt/0f ug{ cltl/Qm pks/0f cfjZos x'G5 . t'ngfTds ?kdf 7fpF w]/} rflxG5 lkeL k|0ffnL h8fgsf nflu ck]Iffs[t l8h]n h]g]/]6/sf] t'ngfdf w]/} 7fpF rflxG5 h'g ;w}+ hldgdf jf 5tdf pknAw gx'g ;S5 . pmhf{ e08f/0fsf nflu pks/0fsf] cfjZostf rf}aL; 306f;Dd pmhf{sf] dfu ;Daf]wg ug{ ;"o{sf] ls/0f ;w}+ pknAw xF'b}g / pknAw ePsf] cj:yfdf l:y/ x'Fb}g\ . cfk"lt{ lgoldt / e/kbf]{ agfpgsf nflu Ps pmhf{ e08f/0f pks/0f h:t} Aof6«L cfjZos x'G5 . Aof6«Lx? jf cGo e08f/0f pks/0fsf] dfun] k|0ffnLsf] nfut a9fpF5 . clgoldt phf{ ;|f]t lbgsf] ;dodf ;d]t 3fd ;w}F pknAw x'Gg . ef}uf]lns cjl:ylt, hnjfo' / cGo jftfj/0fLo kl/l:yltn] ;"o{sf] k|sfzsf] dfqfnfO{ c;/ u5{ . r]tgfsf] sdL cGo hLjfz]if OGwgdf cfwfl/t k|ljlwx?sf] t'ngfdf Psbd} gofF ePsf]n] ;f}o{ lkeL k|ljlw / o;sf] k|of]un] x'g] kmfObfx?af/] dflg;x? ;fdfGotof cglj1 5g\ / o;nfO{ ckgfpg dxFuf] / l9nf] x'G5 . 17 Training manual on Solar Irrigation Pumps | Solar PV Applications Lighting System for Home These PV lighting systems are generally o-grid or stand-alone systems where the only source of energy is solar energy. However, in regions of unreliable grid electricity, solar PV systems are used as a supplement to grid electricity for critical lights. Common applications at home include room lighting, pathway lights, etc. Television and Radio Solar PV systems typically ranging in size from 10 to 120Wp with one battery can be used to power a few LED lights, radio, computer, and television. The devices used in such systems are mainly DC-supplied type which reduces system costs. So, in this case, low powered DC TV is connected that does not require an inverter. Water Pumping In rural areas with no grid connection or unreliable grid electricity, solar water pumping can be used for applications such as irrigation, drinking, aquaculture, washing, and feeding livestock. There are generally two water tanks: one situated near the water source and the other near the village situated at a higher altitude. A high-eciency solar DC or AC water pump lifts water from the lower tank to the upper. The water collected at the upper tank is distributed through a standard pipeline through gravity. Street Light A solar street light is typically composed of an LED lamp, solar panels, battery, and charge controller. The lamp operates on electricity from batteries, charged through the use of a solar PV panel. 18 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;f}o{ lkeLsf] pkof]u 3/sf nflu ljB'tLo k|0ffnL oL lkeL ljB'tLo k|0ffnL ;fwf/0ftof ckm3lu|8 jf :6\ofG83Pnf]g k|0ffnLx? x'g h;df pmhf{sf] Psdfq ;|f]t ;f}o{ pmhf{ xf] . o2kL, ljB'tLo lu|8 e/kbf]{ gePsf] If]qx?df ;f}o{ lkeL k|0ffnLx? dxTjk"0f{ aQLx?sf nflu lu|8 lah'nLsf] k"/ssf] ?kdf k|of]u ul/G5 . 3/df ;fwf/0f ?kdf sf]7fdf k|of]u ul/g] aQL, tyf ;8s aQLdf pkof]u ul/G5 . 6]lnlehg / /]l8of] ;f}o{ lkeL k|0ffnL ;fdfGotof !) b]lv !@) jf6 lks -8ANo'kL_ ;Ddsf] Ps Aof6«Lsf] ;fydf s]xL PnO{8L aQL, /]l8of], sDKo'6/ / 6]lnlehg rnfpg k|of]u ug{ ;lsG5 . tL k|0ffnLx?df k|of]u ul/g] pks/0fx? d'Vo?kdf l8;L3cfk"lt{ ul/g] vfnsf x'G5g\ h;n] k|0ffnLsf] nfut 36fpF5 . To;}n], o; cj:yfdf, sd kfj/ ePsf] l8;L l6eL h8fg ul/G5, h;df OGe6{/ cfjZos kb}{g . kfgL tfGg] kDk lu|8 h8fg gePsf] jf e/kbf]{ lu|8 lah'nL gePsf u|fdL0f If]qdf ;f}o{ pmhf{df cfwfl/t kfgL tfGg] kDksf] k|of]u l;FrfO, vfg]kfgL], df5fkfng, ;/;kmfO, / kz'nfO{ v'jfpg] h:tf sfdsf nflu ug{ ;lsG5 . ;fdfGotof b'O{j6f kfgL 6\ofªsLx? x'G5g\ M klxnf] kfgLsf] ;|f]t glhs / bf];|f] ufpF glhs}sf] cUnf] pmrfOdf /flvG5 . tNnf] 6ofª\sLaf6 kfgL k7fpg pRr Ifdtfsf] ;f}o{ l8;L jf P;L kfgL tfGg] oGq k|of]u ul/G5 . dflyNnf] 6\ofª\sLdf hDdf ePsf] kfgL ;fwf/0f kfOknfOgaf6 u'?Tjfsif{0f -u|flj6L_ dfkm{t\ ljt/0f ul/G5 . ;8s aQL ;f}o{ ;8s aQLdf ;fdfGotof PnO8L aQL, ;f}o{ Kofgn, Aof6«L, / rfh{ sG6«f]n/ x'G5 . ;f}o{ lkeL Kofgnaf6 rfh{ eP/ Aof6«Lsf] ;xof]un] lah'nL aQL ;~rfng x'G5 . 19 Training manual on Solar Irrigation Pumps | 2. Electrical demand load analysis Ecient Energy Utilization The PV system must be designed eciently to minimize costs while being able to cater to the required electrical loads. The load size directly influences the size and cost of the PV system but professionals must advise on using energy- ecient devices. For example, use LED light instead of fluorescent or CFL light. All loads must not run as peak load. People must be aware of load peaking and the eciency of appliances. Both peak load and low-eciency devices increase the cost and size of the PV system. The load must shift peak time to o-peak time to reduce peak demand of the PV sy,stem which can reduce the size of the PV system and hence the cost. Electrical Load Analysis The load of the consumer needs to be correctly calculated for the demand analysis. The hour of operation of load is also equally important for the load analysis. The type of load also needs to be mentioned to gain an understanding of whether it is inductive or resistive and its usage pattern. The load may be AC or DC type and the power rating of the load is usually available in the nameplate of the device or the manufacturer provides a manual in which the power rating is given. If the power rating is not given, then the power can be calculated as: For DC load, For AC load, Power = Voltage x Current. Power = Voltage x Current x Power factor. (line-3ph) The power factor is taken as 0.8 if not specified. The voltage and current ratings are given in the nameplate. Some loads consume low power in standby mode and higher power in an active mode such as a computer. Also, some loads turn on and o automatically, such as iron, refrigerators, etc. These loads are taken into account with their on and o time while surge load must be taken into consideration such as for motors that take high current initially. Load estimation The load calculation requires daily average use of load, the number of loads, and its electrical specification. The specification includes AC or DC type loads, power rating, voltage, and current rating. The total average energy consumption by the load can be calculated by multiplying the number of loads, wattage of load, and the average operation of an hour. While calculating these loads, we must consider the seasonal variation of loads, low ecient loads, and standby power consumption of electrical devices/machines. The loads are variable and under certain conditions, some loads are wise to exclude in a PV system to reduce the size and cost of the PV system (for example, loads that are operated very infrequently). 20 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf @= lah'nL dfusf] nf]8 ljZn]if0f pmhf{sf] k|efjsf/L pkof]u lkeL k|0ffnL cfjZos ljB'tLo nf]8x? k"/f ug{ ;Ifd x'g] x'Fbf nfut sd ug{ s'zntfk"j{s l8hfOg ul/Psf] x'g'k5{ . nf]8sf] k|sf/n] k|ToIf ?kdf lkeL k|0ffnLsf] cfsf/ / nfutnfO{ k|efj kf5{ t/ Joj;flox?n] pmhf{3bIftf pks/0fx? k|of]u ug{ ;'emfj lbg'k5{ . pbfx/0fsf nflu, km\nf]/f];]G6 jf ;LPkmPn lrdsf] ;6\6f PnO8L lrdsf] k|of]u ug{'xf];\ . ;a} nf]8 pRr nf]8df rnfpg' x'Fb}g . dflg;n] pRr nf]8 / pks/0fsf] ;Ifdtfaf/] hfgsf/÷;r]t x'g'k5{ . pRr nf]8 / sd ;Ifd pks/0fx?n] lkeL Kofgnsf] d"No / cfsf/ a9fpF5g\ . lkeL Kofgnsf] r/d dfunfO{ sd ug{ nf]8n] r/d dfu ePsf] ;do -lks 6fOd_ nfO{ dfu sd ePsf] ;do -ckm lks 6fOd_ df kl/jt{g ug'{k5{ h;n] lkeL Kofgnsf] cfsf/ 36fpg ;S5 / To;}n] nfut klg sd x'G5 . ljB'tLo nf]8 ljZn]if0f pkef]Qmfsf] nf]8nfO{ 7Ls;Fu u0fgf u/L dfq} nf]8 ljZn]if0f ug'{ cfjZos x'g hfG5 . nf]8 ljZn]if0fsf nflu ;~rfng x'g] cjlw klg ;dfg ?kdf dxTjk0" f { 5 . of ] cfudgfTds -induc}ve_ jf k|lt/f]wL -resis}ve_ xf] / k|of]usf] :j?k s] x'g] a'em\gsf nflu nf]8sf] k|sf/ pNn]v ul/g' cfjZos x'g hfG5 . nf]8 P;L jf l8;L k|sf/sf] x'g ;S5 / nf]8sf] ;fdYo{ d"NofÍg ;fdfGotof pks/0fsf] &g]dKn]6Údf pknAw x'G5 jf lgdf{tfn] pknAw u/fpg] lgb]{lzsfdf ;fdYo{sf] &/]l6+uÚ lbOPsf] x'G5 . olb kfj/ d"NofÍg lbOPsf] 5}g eg], kfj/ lgDg ¿kdf u0fgf ug{ ;lsG5 M l8;L nf]8sf nflu P;L nf]8sf nflu kfj/ Ö ef]N6]h x s/]G6 kfj/ Ö efN] 6h] x s/]G6 x kfj/ ÆofS6/ (nfOg3# kmh] ) kfj/ ÆofS6/ pNn]v geP )=* lnOg]5 . ef]N6]h / s/]G6sf] dfqf g]dKn]6df lbOPsf] x'G5 . s]xL nf]8x? :6\of08afO{ df]8df sd kfj/ / ;lqmo cj:yfdf pRr kfj/ vkt u5{g\ h:t} M sDKo'6/ . ;fy}, Ol:t/L -cfO/g_, /]lkm|h]/]6/ h:tf nf]8df :jrflnt ?kdf cg / ckm x'G5g\ . o:tf nf]8nfO{ rfn" / aGb x'g] ;dodf Wofg /fVg'k5{ hals ;'?df pRr s/]G6 lng] df]6/ h:tfsf nflu ;h{ nf]8nfO{ Wofgdf /fVg'k5{ . nf]8 cg'dfg nf]8sf] lx;fa lgsfNg nf]8sf] b}lgs cf};t k|of]u, ;+Vof / o;sf] ljB'tLo lglb{li6s/0f h?/L k5{ . lglb{li6s/0fdf P;L jf l8;L k|sf/sf nf]8x?, kfj/ dfqf, ef]N6]h / s/]G6sf] dfqf ;dfj]z x'G5 . nf]8n] cf};tdf vkt ug]{ s'n pmhf{sf] lx;fa nf]8sf] ;+Vof, nf]8sf] jf6]h, / Ps 306fsf] cf};t ;~rfngnfO{ u'0fg u/]/ lgsfNg ;lsG5 . oL nf]8x?sf] lx;fa lgsfNb} ubf{ xfdLn] nf]8sf] df};dL leGgtf, phf{ bIftf, / ljB'tLo pks/0f÷oGqx?sf] kfj/ vktnfO{ ljrf/ ug'{k5{ . nf]8x? a9L / 36L x'G5g\ / lglZrt kl/l:yltdf lkeL Kofgnsf] cfsf/ / nfut 36fpg lkeL Kofgndf s]xL nf]8x? cnu ug'{kg]{ x'G5 . pbfx/0fsf nflu w]/} b'n{e -clgoldt_ ?kdf ;~rfng ul/g] nf]8x? . 21 Training manual on Solar Irrigation Pumps | Consideration in load estimation Many variables can aect the load estimation. The load calculation is not straightforward but dicult to calculate due to many variables. The several considerations taken into account in the calculation of loads are: i. Use of manufacturer’s manual for the energy consumption of load and power rating of the load ii. Peak power during operation iii. Frequency and duration of operation iv. The type of load (either AC or DC) v. The voltage level required by the load vi. The seasonal and daily variation of loads vii. Eciency and the use of loads viii. The duty cycle of load and energy conservation taken into account ix. The future expansion of load Cable Size We need to calculate the size of the cables based on the voltage loss and ampacity. Ampacity is defined as the maximum current carrying capacity of any conductor under certain cable properties, installation conditions, and the surrounding environment. For easier access, there are online tools that can help with cable calculations such as this: https://photovoltaic-software. com/solar-tools/voltage-drop-calculator-dc-ac. 22 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf nf]8 cg'dfgdf Wofg lbg'kg]{ a'Fbfx? nf]8 cg'dfgnfO{ w]/} s'/fx?n] c;/ ug{ ;S5 . nf]8sf] lx;fa lgsfNg Wofg /fVg'kg]{ a'Fbfx? M != nf]8sf] pmhf{ vkt / nf]8sf] kfj/ dfqfsf nflu lgdf{tfn] lbPsf] lgb]{lzsfsf] k|of]u @= ;~rfngsf] qmddf x'g] pRr kfj/ vkt #= ;~rfngsf] cjlw / lg/Gt/tf $= nf]8sf] k|sf/ -P;L jf l8;L_ %= nf]8sf nflu cfjZos ef]N6]hsf] dfqf -:t/_ ^= nf]8sf] df};dL / b}lgs leGgtf &= sfo{Ifdtf / nf]8sf] k|of]u *= nf]8 / pmhf{ ;+/If0fsf] Jojxf/ (= nf]8sf] eljio la:tf/ s]an ;fOh ef]N6]h n; / PlDkl;l6 -s]ann] s/]G6 wfGg ;Sg] Ifdtf_ sf] cfwf/df xfdLn] tf/sf] cfsf/sf] d"NofÍg ug'{kg]{ x'G5 . tf/sf] ljz]iftf, h8fgsf] kl/l:ylt / jl/kl/sf] jftfj/0f cg';f/ s'g} klg ;~rfnssf] clwsQd s/]G6 k|jfx ug]{ IfdtfnfO{ PlDkl;6L elgG5 . tf/sf] d"NofÍg tyf lx;faaf/] ;xh ?kdf a'em\g s]xL cgnfOg ;fdu|Lsf] ;xof]u lng ;lsG5, h:t} htps://photovoltaic- sovware.com/solar-tools/voltage-drop-calculator-dc-ac 23 Training manual on Solar Irrigation Pumps | 3. Solar PV System Component A typical o-grid Solar PV system generally consists of solar panels, a battery bank, a charger controller, and an inverter, as shown in the figure below. Figure 2 Solar PV System Component for a typical O-grid system (LSP-International, 2021) Similarly, the major components in other types of solar PV systems are, " Solar PV on-grid systems: solar panels, inverter " Solar water pumping systems: solar panels, controller, and pump 24 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf #= ;f}o{ lkeL k|0ffnLsf] sDkf]g]G6 tnsf] lrqdf b]vfOPsf] cg';f/, Ps ;fdfGo ckm3lu|8 ;f}o{ PV k|0ffnLdf ;fdfGotof ;f}o{ Kofgn, Aof6«L a}+s, rfh{/ sG6f« n] / / OGe6{/ x'G5 . ;f}o{ ls/0f Aof6«L a}+s rfh{ sG6«f]n/ ;f}o{ lkeL Kofgn P;L nf]8\; ckm lu|8 OGe6{/ tl:j/ @ ;fwf/0f ckm3lu|8 k|0ffnLsf] nflu ;f}o{ lkeLsf efux? -PnP;kL3cGt/f{li6«o, @)@!_ To:t}, s]xL cGo k|sf/sf ;f}o{ lkeL k|0ffnLsf dxTjk"0f{ tTjx? M " ;f}o{ lkeL cg3lu|8 k|0ffnL M ;f}o{ Kofgn, OGe6{/ " ;f}o{ kfgL tfGg] k|0ffnL M ;f}o{ Kofgn, sG6«f]n/ / kDk 25 Training manual on Solar Irrigation Pumps | Solar PV module A solar cell, or photovoltaic cell, uses the photovoltaic eect to convert radiated energy from the sun to electricity. Its electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Generally, the open-circuit voltage (when the cell is not connected to any load) is approximately 0.5 to 0.6 volts. Individual solar cell devices can be combined to form modules, otherwise known as solar panels. Figure 3 Solar PV cell, module, panel, and array (FSEC, 2021) Types of solar module There are three broad categories of technology used for the formation of PV cells: (i) Crystalline silicon, (ii) Thin-film, and (iii) Special (Compound semiconductor based). The Crystalline silicon (wafer-based) cell type accounts for most of PV cell production while the thin-film type is a newer technology. 26 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;f}o{ lkeL Kofgn ;f}o{ ;]n, jf kmf]6f]ef]N6flos -lkeL_ ;]nn] ;"o{af6 ljls/l0ft pmhf{nfO{ lah'nLdf ?kfGt/0f ug{ kmf]6f]ef]N6flos k|efjsf] k|of]u u5{ . o;sf] ljB'tLo ljz]iftfx?, h:t} s/]G6, ef]N6]h jf k|lt/f]w, ;f}o{ k|sfz cg';f/ leGg x'G5g\ . ;fdfGotof, cf]kg3;ls{6 ef]N6]h -ha ;]n s'g} nf]8df h8fg x'Fb}g_, nueu )=% b]lv )=^ ef]N6 x'G5 . w]/} ;f}o{ ;]nx?nfO{ hf]8]kl5 To;nfO{ ;f}o{ Kofgn eg]/ lrlgG5 . Kofgn kmf]6f]ef]N6flos -lkeL_ ;]n Kofgn P/] tl:j/ # ;f}o{ lkeL ;]n, To;sf] ;+/rgf, Kofgn, / P/] -PkmP;O;L, @)@!_ ;f}o{ Kofgnsf] k|sf/ lkeL ;]n agfpg k|of]u ul/g] k|ljlwsf] tLgj6f lj:t[t k|sf/x? 5g\ M != lqmi6lng l;lnsg\\, @= yLg lkmNd #= ljz]if -sDkfpG8 ;]dL3s08S6/ cfwfl/t_ . lqmi6lng l;lnsg\\ -j]km/df cfwfl/t_ ;]nsf] k|sf/ w]/}h;f] lkeL ;]n pTkfbgsf nflu lhDd]jf/ x'G5 ha sL kftnf]3l/n ;]n k|sf/ Ps gofF k|ljlw xf] . 27 Training manual on Solar Irrigation Pumps | Figure 4 PV technology family tree (Grid Nepal, 2014) Monocrystalline Solar Panels (Mono-SI) One can easily recognize monocrystalline silicon solar panels from the  uniform dark look  and the  rounded edges. The silicon’s high purity causes this type of solar panel to have one of the highest eciency rates, with the newest ones reaching above 20%. Monocrystalline panels  have a high power output, occupy less space, and last the longest. Another advantage of monocrystalline panels is that they tend to be slightly less aected by high temperatures compared to polycrystalline panels. 28 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf lkeL ;]nsf k|sf/x? ljz]if lqmli6lng l;lnsg\ yLg lkmNd sDkfp08 ;]dL3s08S6/ kf]ln lqmli6lng Pdf]{km;3P;cfO{ df]gf] lqmi6lng 6A8]g P3P;cfO{ sk/ OlG8od u}lnod ;]n]gfO8 Sof8ldod 6]n'/fO8 tl:j/ $ lkeL k|ljlw j+zj[If -lu|8 g]kfn, @)!$_ df]gf] lqmi6lng ;f}o{ Kofgnx? -df]gf]3P;cfO{_ Ps;dfg uf9f b]lvg] / uf]nf] lsgf/f ePsf] Psn:kml6s ;f}o{ KofgnnfO{ ;xh?kdf klxrfg ug{ ;lsG5 . l;lnsg\sf] pRr z'4tfn] o;k|sf/sf] ;f}o{ KofgnnfO{ pRrQd sfo{Ifdtf b/ ePsf] agfpF5 / gofF Kofgnx?sf] @) k|ltzteGbf dfly ;Dd kfj/ bIftf k'u]sf] kfOG5 . df]gf]lqmi6lng Kofgndf pRr kfj/ pTkfbg x'G5, yf]/} :yfg cf]u6\5 / bL3{sfnLg x'G5 . pRr tfkqmddf klg yf]/} k|efljt x'g' kf]ln lqmi6lng Kofgnsf] t'ngfdf df]gf] lqmi6lng Kofgnsf] csf]{ kmfObf xf] . 29 Training manual on Solar Irrigation Pumps | Polycrystalline Solar Panels (Poly-SI) You can quickly distinguish these panels because this type of solar cell is square, its angles are not cut, and it has a blue, speckled look. They are made by melting raw silicon, which is a  faster and cheaper process than that used for monocrystalline panels. This leads to a lower eciency (less than 20%), lower space eciency, and a shorter lifespan since they are aected by hot temperatures to a greater degree. The choice between mono- and polycrystalline types of solar panels will depend on the specific situation. The first option oers a slightly higher space eciency at a slightly higher price but power outputs can be the same if the array size is designed accordingly. Figure 5 Types of Crystalline Panel technology (Sungold Solar, 2021) 30 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf kf]ln lqmi6lng ;f}o{ Kofgn -kf]ln3P;cfO{_ o;k|sf/sf] KofgnnfO{ l5§} g} klxrfg ug{ ;lsG5 lsgls ;f}o{ ;]n juf{sf/, s'gf gsfl6Psf] / gLnf] wAaf ePsf] b]lvG5 . sRrf l;lnsg\nfO{ kUnfP/ of] tof/ ul/Psf] x'G5, h'gdf df]gf] lqmi6lngdf k|of]u x'g] eGbf l56f] / ;:tf] k|s[of x'G5 . o;sf] kfj/ bIftf sd x'G5 -@) k|ltzteGbf sd_, 7fpF a9L lnG5 / 5f]6f] hLjgsfn x'G5 lsgeg] of] pRr tfkqmdaf6 cToflws k|efljt x'G5 . df]gf]3 / kf]ln lqmi6lng k|sf/sf] ;f}o{ KofgnaLr s'g rog ug]{ ljifo ljlzi6 kl/l:yltdf lge{/ x'g] xf] . klxnf] ljsNkn] cln a9L d"Nodf sd 7fpF lnG5 t/ P/]sf] cfsf/ /fd|/L l8hfOg ul/Psf] 5 eg] kfj/ pTkfbg ;dfg x'g ;S5 . kf]nL kf]ln lqmi6lng Kofgn agfpgsf nflu l;lnsg\ sf 6'qmfnfO{ Ps cfk;df kUnfP/ j]km/ tof/ ul/G5 . df]gf] df]gf] lqmi6lng Kofgnsf nflu ;]n agfpg k|To]s af/ df l;lnsg\ agfP/ j]km/df ljeflht ul/G5 . tl:j/ % ls|i6nLg Kofgn k|ljwLsf lsl;dx? -;g\uf]N8 ;f]nf/, @)@!_ 31 Training manual on Solar Irrigation Pumps | Rated output specifications and solar panels Rated output for solar panels at dierent light intensities (W/m2) is shown in the figure below. The “knee” of the curves is where the most power output of the panel is generated. Figure 6 Voltage and current characteristics of solar panel (Altestore, 2021) Open Circuit Voltage (Isc) Open circuit voltage is the voltage output of a solar panel with no load. If you measure with a voltmeter across the plus and minus leads, you will read V . Since the solar panel is not connected to anything, there is no load on it, and it is OC producing no current. This is a very important number, as it is the maximum voltage that the solar panel can produce under Standard Test Conditions, so this is the number to use when determining how many solar panels you can wire in series going into your inverter or charge controller. Remember, fuses and breakers protect wires against over-current, not over-voltage. Short Circuit Current (Isc) Short Circuit Current is the current a solar panel produces when the plus and minus of the solar panel's wires are short- circuited. If you measure with an ammeter across the plus and minus leads, you will read I . This is the highest current SC the solar panels will produce under standard test conditions. When determining how many amps a connected device can handle, like a solar charge controller or inverter, the I is SC used, generally multiplied by 1.25 for National Electrical Code (NEC). 32 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf dfqfltt pTkfbg lglb{li6s/0f / ;f}o{ Kofgn ljleGg k|sfz tLj|tf -jf6 k|lt ju{ ld6/_ df ;f}o{ Kofgnx?sf] d"NofÍg ul/Psf] pTkfbg lgDg lrqdf b]vfOPsf] 5 . ;f}o{ Kofgnsf] ;a}eGbf a9L kfj/ pTkfbg x'g] laGb' lrqdf b]vfOPsf] cg';f/ 3'dfjsf] 3'F8fdf kb{5 . Isc clwsQd kfj/ KjfOG6 0 ef]N6Ù clwsQd PDK; pRr kfj/ cfp6k'6 Voc 0 PlDkc/, clwsQd ef]N6 tl:j/ ^ ;f}o} Kofgnsf] ef]N6 / s/]G6sf] Jojxf/ -PN6L:6f]/, @)@!_ vn' f efN] 6h] -Voc_ cf]kg ;ls{6 ef]N6]h ;f}o{ Kofgnsf] nf]8ljxLg ef]N6]h cfp6k'6 xf] . obL tkfO{ Kn; / dfOg; ePsf] ln8x?df ef]N6ld6/n] dfkg ug'{x'G5 eg] -Voc_ k9\g'x'g]5 . ;f}o{ Kofgn s]xL;Fu ghf]l8Psf]n] o;df s'g} nf]8 x'Gg, / o;n] ljB't pTkfbg ul//x]sf ] x'Fb}g . of] ef]N6]h cfp6k'6 Ps cToGt} dxTjk"0f{ ;+Vof xf], lsgeg] :6fG88{ 6]:6 slG8;gdf ;f}o{ Kofgnn] pTkfbg ug{ ;Sg] of] clwsQd ef]N6]h xf], To;}n] tkfO{n] cfkm\gf] OGe6{/ jf rfh{ sG6«f]n/df k'Ug] >[v+nfdf sltj6f ;f}o{ Kofgn h8fg ug{ ;lsG5 eg]/ lgwf{/0f ubf{ of] ;+Vof k|of]u ug{ ;lsG5 . :d/0f /xf];\, km\o'h / a|]s/x?n] tf/nfO{ cToflws s/]G6af6 hf]ufpF5, pRr ef]N6]haf6 xf]Og . ;6 { ;ls6{ s/G] 6 -Isc_ ;f}o{ Kofgnsf] tf/sf] Kn; / dfOg; ;6{ ;ls{6 x'Fbf ;f}o{ Kofgnn] pTkfbg ug]{ s/]G6nfO{ ;6{ ;ls{6 s/]G6 elgG5 . olb tkfO{+n] Kn; / dfOg; ln8x¿df PlDd6/sf] ;fy dfkg ug{'x'G5 eg], tkfO{+n] Isc sf] l/l8ª kfpg'x'g]5 . of] pRrtd s/]G6 xf] . h'g ;f}o{ Kofgnsf] :6fG88{ 6]:6 slG8;gn] pTkGg u/fpF5 . hl8t oGqn] ;f}o{ rfh{ sG6«f]n/ jf OGe6{/ h:tf slt PDK; XofG8n ug{ ;S5 eGg] lgwf{/0f ubf{, Isc k|of]u ul/G5, ;fdfGotof /fli6«o ljB'tLo sf]8 -NEC_ sf] cfwf/df !=@% n] u'0fg ul/G5 . 33 Training manual on Solar Irrigation Pumps | Maximum Power Point Tracking The maximum power point of a solar panel or solar array is the operating point where the solar panel/array generates the maximum power available at any given instance. Similarly, Maximum Power Point Tracking (MPPT) is an algorithm that tracks the maximum power point of a solar panel/ array at any given instance. The MPPT algorithm tracks the IV (Current and Voltage) curve and adjusts the voltage and current to yield maximum power. We know, P = I * V In the IV curve below, the ‘blue’ curve represents the power and the ‘orange’ curve represents the voltage and current. We can see that the maximum power can be extracted at V and I . Note that the IV curve changes at dierent mp mp radiation i.e. throughout the day, and the MPPT algorithm constantly tracks this maximum point. Figure 7 PV Panel IV curve and MPPT Tracking (Mayfield, 2021) The optimal Vmp and Imp are given in the solar panel datasheet which is specified for the Standard Test Conditions (STC). 34 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf clwsQd kfj/ kfO] G6 6o« flsª -Pdlklkl6_ ;f}o{ Kofgn jf ;f}o{ P/]sf] clwsQd kfj/ laGb' eg]sf] ;~rfng laGb' xf] hxfF ;f}o{ Kofgn÷P/]n] s'g} klg cj:yfdf pknAw clwsQd kfj/ pTkfbg u5{ . o;}u/L, clwsQd kfj/ kf]OG6 6«oflsª -PdkLkL6L_ Ps PNuf]l/bd xf] h;n] s'g} klg ;dodf ;f}o{ Kofgn÷P/]sf] clwsQdk fj/ kf]OG6 k5\ofpF5 . PdkLkL6L ul0ftLo Kofgnn] cfO{eL -s/]G6 / ef]N6]h_ se{nfO{ k5\ofpF5 / clwsQd kfj/ pTkfbg ug { ef]N6]h / s/]G6 ;dfof]hg u5{ . xfdLnfO{ yfxf 5, kfj/ -kL_ Ö s/]G6 -cfO{_ *ef]N6]h -eL_ tnsf] cfO{eL se{df, &lgnf]Ú se{n] kfj/sf] k|ltlglwTj u5{ / &;'GtnfÚ /u+ sf ] se{n] ef]N6]h / s/]G6sf] k|ltlglwTj u5{ . Vmp / Imp df clwsQd kfj/ lgsfNg ;lsG5 . cfO{eL se{ km/s3km/s ljls/0fdf cyf{t lbgsf] ljleGg ;dodf kl/jt{g eO/xG5, / PdkLkL6L PNuf]l/bdn] nuftf/ o; clwsQd laGcbl'nwsfOQ{ dk 5k\ofjf/pg] ub{5 . s/]G6 Vs ef]N6]h clwsQd kfj/ KjfOG6 kfj/ Vs ef]N6]h ef]N6]h-V_ tl:j/ & lkeL Kofgn cfO{eL se{ / PdkLkL6L 6«oflsª\u -kblrXg_ -d]lkmN8, @)@!_ Vmp / Imp ;f}o{ Kofgnsf] 8f6fzL6df lbOPsf] x'G5 h'g :6fG88{ 6]:6 slG8;gsf nflu lglb{i6 ul/Psf] x'G5 . 35 s/]G6-A_ kfj/-W_ Training manual on Solar Irrigation Pumps | Figure 8 Technical Specification of a typical Solar Panel (GAF DecoTech, 2021) Array Sizing The solar array sizing results in the total peak Wattage (Wp) provided to meet the demand. During solar array sizing, losses in the generation need to be factored in to obtain the desired power in the system. The average daily peak sun time plays a major role in sizing the PV system. The average daily peak sun hours in Nepal is 4.6 hours (average from SolarGIS GHI map). Factors that cause losses in solar panel power output are: " Solar irradiance " Power loss due to cell temperature " Nameplate DC Rating " Diode and Connection loss " Mismatch losses " DC and AC Wiring " Sun-Tracking loss " Shading losses " Soiling losses " Controller loss 36 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf tl:j/ * Ps ljlzi6 ;f}o{ Kofgnsf] k|fljlws lglb{li6s/0f -hLPPkm 8]sf]6]s, @)@!_ P/] ;fOlhª ;f}o{ P/] ;fOlhªn] pknAw s'n kLs jf6]h -Wp_ sf] dfu cfk"lt{ u5{ . ;f}o{ P/]sf] ;fOlhª ug]{ qmddf Kofgndf jfl~5t kfj/ k|fKt ug{ pTkfbgdf x'g] n;nfO{ Wofgdf /fVg h?/L x'G5 . cf};t b}lgs pRrQd ;"o{ pbfpg] ;don]] lkeL Kofgnsf] cfsf/ lbg Ps k|d'v e"ldsf lgjf{x u5{ . g]kfndf cf};t b}lgs pRrQd 3fd nfUg] ;do $=^ 306f xf] . ;f}o{ Kofgnsf] kfj/ pTkfbgdf n; Nofpg] sf/0fx? M " ;f}o{ ljls/0faf6 n; " ;]nsf] tfkqmdn] kfj/df n; " g]dKn]6 l8;L /]l6ª\uaf6 leGgtfn] n; " 8fo8 / h8fg n; " Kofgnx?sf] leGgtfn] n; " l8;L / P;L jfol/ª\u n; " ;g36«]lsª\u n; " 5fofFFsf] sf/0fn] x'g] n; " Kofgndf w'nf]sf] sf/0fn] x'g] n; " sG6«f]n/ n; 37 Training manual on Solar Irrigation Pumps | Additionally, as a general rule of thumb, losses in generation can be taken into account with a factor of 0.6 to 0.7. The general steps for array sizing are, " Determine energy demand in Wh (watt-hours) " Use the following formula to calculate the array size (Total Energy [Wh]) Array size (Wp) = 4.6*Wp*0.7 Where, Wh = Watt-hour (power x time) 4.6 = Total peak sun hours in Nepal Wp = watt size of modules to be used 0.7 = Losses in modules due to factors like temperature, soiling etc. Note: This calculation is used for the rule-of-thumb sizing of a solar array. The peak sun hours and losses are specific to the site conditions and components used. Once the array size has been determined, the arrangement of solar panels in the array i.e. the number of panels in series and parallel must be compatible with the charge controller or the inverter that it will directly connect to. To check this, make sure the array voltage and current are within acceptable limits of the charge controller or the inverter. 38 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf To; cltl/Qm, ;fdfGotof pTkfbgdf x'g] n;nfO{ )=^ b]lv )=& ;Dd sf/sdf lng ;lsG5 . P/] ;fOlhªsf nflu ;fdfGo r/0fx?, " pmhf{sf] dfunfO{ jf63cfj/df lgwf{/0f ug]{ " P/]sf] ;fOlhªaf/] lx;fa ug{ lgDg ;"q k|of]u ug]{ s'n pmhf{ -jf63cfj/_ P/]sf] ;fOh -8ANo'kL_ Ö $=^* 8ANo'kL*)=& hxfF, 8ANo'Pr Ö jf63cfj/ -kfj/ x ;do_ $=^ Ö g]kfndf pRr 3fd nfUg] s'n ;do 8ANo'kL Ö k|of]u x'g] Kofgnsf] ;fOh -Pp6f Kofgnsf] ;fOh_ )=& Ö tfkqmd, w'nf] nufotsf sf/0fn] ;+/rgfdf cfpg] n; gf]6M of] lx;fa ;f}o{ P/]sf] cg'dfg ug{sf] nflu dfq k|of]u ul/G5 . pRr 3fd nfUg] cjlw / n; :ynsf] cj:yf / k|of]u ul/Psf] tTj cg';f/ km/s x'G5 . P/]sf] cfsf/ lgwf{/0f eO;s]kl5 P/]df ;f}o{ Kofgnsf] Joj:yf cyf{t >[+vnf -series_ / ;dfgfGt/ -parallel_ Kofgnsf] ;+Vof rfh{ sG6«f]n/ jf OGe6{/ ;Fu ldNg'k5{ . o;nfO{ k/LIf0f ug{ P/] ef]N6]h / s/]G6 b'a} rfh{ sG6«f]n/ jf OGe6{/sf] :jLsfo{ ;Ldf leq /x]sf] ;'lglZrt ug'{k5{ . 39 Training manual on Solar Irrigation Pumps | Batteries A battery is an electrochemical device that can store electrical energy in a chemical form. It contains various cells and each cell contains a positive terminal (or cathode) and a negative terminal (or anode). The electrolyte allows the ion to flow between terminals. The energy produced by the PV array and stored in the battery is used at night when no sunlight is available or when there is minimal sunlight in the daytime. Figure 9 Battery and its components (BCcampus, n.d.) Types and operation of a battery Batteries can be categorized as Primary (non-rechargeable) and Secondary (rechargeable) batteries. Primary batteries are not suitable in solar PV applications because the battery needs to be charged and discharged. There are many types of batteries used in commercial and residential applications. Commonly used batteries in a solar PV system are: Flooded Lead Acid Battery In flooded lead-acid batteries, the positive and negative lead plates, which are made of dierent compositions, are immersed in sulfuric acid solution also known as electrolyte. The voltage of the individual cell is approximately 2V regardless of the cell size. Electricity flows from the battery as soon as there is a circuit between the positive and negative terminals when any load (appliance) that needs electricity is connected to the battery. The flooded lead-acid batteries need frequent maintenance i.e. the electrolyte needs to be topped up with distilled water to maintain the desired electrolyte level inside the battery. The condition of the battery can be checked using a hydrometer which measures the specific gravity of the electrolyte. 40 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Aof6«Lx? Aof6«L Ps On]S6«f]s]ldsn pks/0f xf] h;n] ljB't pmhf{nfO{ /;folgs ?kdf e08f/ ug{ ;S5 . o;df cg]sf}+ ;]nx? x'G5g\ / k|To]s ;]ndf kf]lhl6e 6ld{gn -cathode_ / g]u]l6e 6ld{gn -anode_ ;dfj]z x'G5 . On]S6«f]nfO6n] cfog (ion) nfO{ 6ld{gnx?aLr k|jfx ug{ cg'dlt lbG5 . lkeL P/]n] pTkfbg u/L Aof6«Ldf e08f/0f u/]sf] pmhf{ /flt ;"o{sf] k|sfz gePsf] a]nf jf lbgsf] ;dodf ;"o{sf] k|sfz cToGt} yf]/} /x]sf] a]nf k|of]u ul/G5 . kf]h]l6e 6ld{gn k|f]6]lS6e s}l;ª\u lgu]l6e 6ld{gn ;]n l8efO8/ kf]h]l6e On]S6«f]8 -ln8 8fcS;fO8_ lgu]l6e On]S6«f]8 -ln8_ 8fONo'6 H SO 2 4 tl:j/ ( Aof6«L / o;sf tTjx? -aL;L SofDk;, Pg=8L=_ Aof6«Lsf] k|sf/ / ;~rfng Aof6«LnfO{ k|fylds -rfh{ ug{ x'g]_ / dfWolds -rfh{ ug{ gx'g]_ u/L juL{s/0f ug{ ;lsG5 . k|fylds Aof6«L ;f}o{ lkeLdf pko'Qm x'Gg lsgeg] Aof6«LnfO{ rfh{ / l8:rfh{ ug{ cfjZos x'G5 . 3/fozL / Joj;flos k|of]hgsf nflu ljleGg k|sf/sf Aof6«Lx?sf] k|of]u ul/G5 . ;f}o{ lkeL Kofgndf ;fwf/0ftof k|of]u ul/g] Aof6«Lx? lgDg k|sf/sf x'G5g\ M Æn8]8 ln8 Pl;8 Aof6«L Æn8]8 ln8 Pl;8 Aof6«Ldf ljleGg ;+/rgfn] ag]sf kf]lhl6e / g]u]l6e ln8 Kn]6x?nfO{ ;Nkm\o'l/sP l;8 -h;nfO{ On]S6«f]nfO6 klg elgG5_ leq 8'afOG5 . ;]nsf] cfsf/nfO{ jf:tf gu/] Psn ;]nsf] ef]N6]h sl/a @ ef]N6sf] x'G5 . ljB'tsf] cfjZos x'g] s'g} pks/0fnfO{ Aof6«L;Fu hf]8\bf kf]lhl6e / g]u]l6e 6ld{gnsf] aLrdf kl/ky tof/ x'G5 h;n] ubf{ Aof6«Laf6 lah'nL k|jfx x'G5 . Æn8]8 ln83Pl;8 Aof6«LnfO{ lgoldt dd{t cfjZos x'G5 cyf{t\ Aof6«Lleq cfjZos On]S6«f]nfO6sf] :t/ sfod /fVg On]S6«f]nfO6nfO{ l8l:6N8 jf6/ cfjZostf cg';f/ ykL /fVg'k5{ . Aof6«Lsf] cj:yf xfO8«f]ld6/sf] k|of]u u/]/ k/LIf0f ug{ ;lsG5 h;n] On]S6«f]nfO6sf] ljlzi6 u'?Tjfsif0f{ -:k]l;lkms u|feLl6_ gfK5 . 41 Training manual on Solar Irrigation Pumps | VLRA battery VRLA battery (Valve-Regulated Lead-Acid battery), is a maintenance-free lead-acid rechargeable battery. Being maintenance-free and not requiring frequent distil water top-up, they can be used in applications where frequent maintenance and monitoring can be a challenge (for example, in remote locations). However, they do require cleaning and functional testing. AGM battery AGM batteries (absorbed glass mat) are a type of sealed, or valve-regulated lead-acid battery, the electrolyte in an AGM battery is absorbed in glass mats which are sandwiched in layers between the plates. The battery is completely sealed and individual cell conditions cannot be checked with a hydrometer. Vents prevent pressure build-up in case of gassing. These require lower voltage charge controls and have a life expectancy of 2-5 years and 5-10 years for higher quality gel cell batteries. Nickel-Cadmium Batteries Nickel-Cadmium batteries consist of positive electrodes made from nickel-hydroxide (Ni(OH) ) and negative electrodes 2 made from cadmium (Cd) and immersed in an alkaline potassium hydroxide (KOH) electrolyte solution. These batteries have a long life, low maintenance, survivability from excessive discharges, excellent low-temperature capacity retention, and non-critical voltage regulation requirements which makes them suitable for solar application. But the high cost and limited availability are the main disadvantages of these batteries. Lithium-ion batteries Lithium-ion (Li-ion) batteries have electrodes made of lightweight lithium and carbon. These batteries can be easily used in place of traditional lead-acid batteries and Nickel-Cadmium batteries. Li-ion batteries have higher energy density and higher eciency compared to lead-acid batteries and can last for more than 10 years. The main disadvantage of Li-ion is that it is relatively expensive than lead-acid and Nickel-Cadmium batteries.  Battery bank sizing and Calculations For calculating the battery sizing, the AC energy consumption can be converted in DC by dividing AC energy consumption by inverter eciency. The considerations for battery sizing are autonomy days (number of days requiring back-up in case of low/no PV generation), depth of discharge (DoD), the eciency of the battery, and the system voltage at which the battery is configured. The general formula to calculate the battery bank is, (Wh* DoA) Ah = (Vs*DoD*Losses) 42 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf eLcf/PnP Aof6«L eLcf/PnP Aof6«L -eNe3/]u'n]6]8 ln83Pl;8 Aof6«L_, Ps dd{t/lxt ln83Pl;8 hg' k'g{rfh{ ug{ ;Sg] Aof6«L xf] . dd{t ug{ gkg]{ / af/Daf/ l8l:6N8 jf6/ dflyaf6 /fVg cfjZos gkg]{ x'gfn] lgoldt dd{t / cg'udg r'gf}tLk"0f{ x'g] :yfgdf k|of]u ug{ ;lsG5 -pbfx/0fsf nflu b'ud{ If]qdf_ . o2kL ltgLx?sf] ;kmfO / sfof{Tds Ifdtf k/LIf0f h?/L x'G5 . PhLPd Aof6«L PhLPd Aof6«L -PAhA8{ Unf; Dof6_ Ps k|sf/n] aGb ul/Psf], jf eNe3lgolGqt ln83Pl;8 Aof6«L xf], PhLPd Aof6«Ldf /x]sf] On]S6«f]nfO6 Unf; Dof6df lehfOG5 h'g Kn]6\;sf] txsf] aLrdf n]kg ul/G5 . ;]nnfO{ xfO8«f]ld6/n] k/LIf0f ug{ g;Sg] u/L Aof6«Lx? k"0f{?kdf l;n ul/G5 . e]G6;\n] UofF; el/Psf] cj:yfdf bafa -rfk_ lgoGq0f u5{ . logLx?nfO{ sd ef]N6]hsf] rfh{ lgoGq0f cfjZos x'G5 / o;sf] b'O{b]lv kfFr jif{ cfo' x'G5 . pRr u'0f:t/sf] h]n ;]n Aof6«Lx? h8fg eP kfFrb]lv bz jif{ cfo' x'g] ck]Iff ul/Psf] 5 . lgs]n Sof8ldod Aof6«L lgsn] 3Sof8ldod Aof6L« x?df posi}ve On]S6«f]8\; lgs]n xfO8«f]S;fO8 (Ni(OH)) af6 / nega}ve On]S6«f]8\; -cd_ af6 ag]sf] x'G5 h;nfO{ cNsnfOg kf]6fl;od xfO8«f]S;fO8 (KOH) sf] On]S6«f]nfO6 ld>0fdf 8'afOG5 . oL Aof6«Lx?sf] cfo' nfdf] x'G5, sd dd{t ug'{k5{, cToflws l8:rfh{af6 aRg] Ifdtf, pTs[i6 sd tfkdfg wf/0f Ifdtf / hf]lvd/xLt ef]N6]h lgodg x'G5 h;n] ;f}o{ phf{sf] k|of]usf nflu pko'Qm agfpF5 . pRr nfut d"No / ;Lldt pknAwtf eg] oL Aof6«Lx?sf] d'Voa ]kmfObfx? 5g\ . lnlyod3cfof]g Aof6«L lnlyod3cfof]g Aof6«Lx?sf] On]S6«f]8x? sd jhg ePsf] lnlyod / sfa{gaf6 ag]sf x'G5g\ . oL Aof6«Lx? k/Dk/fut\ ln83 Pl;8 Aof6«Lx? / lgs]n Sof8ldod Aof6«Lx?sf] :yfgdf k|of]u ug{ ;lsG5 . lnlyod3cfof]g Aof6«Lx?sf] ln8 Pl;8 / lgs]n Sof8ldod Aof6«Lx?sf] t'ngfdf pRr pmhf{ 3gTj / pRr sfo{Ifdtf x'G5 / o;sf] cfo' bzjif{eGbf dfly x'G5 . ln8 Pl;8 / lgs]n Sof8ldodeGbf t'ngfTds ?kdf a9L dxFuf] x'g' ln3cfof]g Aof6«Lsf] k|d'v a]kmfObf xf] . Aof6«L a}+s ;fOlhª / u0fgf Aof6«Lsf] ;fOlhª\u u0fgf ug{, P;L pmhf{ vktnfO{ l8;Ldf ?kfGt/0f ug{ ;lsG5 . P;L pmhf{ vktnfO{ OGe6{/sf] kfj/ bIftfn] efu u/]/ l8;Ldf lx;fj ug{ ;lsG5 . Aof6«L a}ª\s u0fgf ug]{ ;fdfGo ;"q, Wh -8ANo' Pr_ * DoA -8LP_ Aof6«Lsf] Ah -PPr_ Ö Vs -eL_ * DoD -8L8L_ * Losses -n;_ 43 Training manual on Solar Irrigation Pumps | Where, Ah is the Battery size in Ampere hour Wh is the total energy requirement (Watt-hour) DoA is the days of autonomy (generally 1.5 for hybrid systems (provision for grid charging, 2 for stand-alone) V is the system voltage (12V, 24V, 48V, etc.) S DoD is the depth of discharge (0.8 for 80% discharge) To meet the battery bank size, batteries are configured in series and parallel. The total battery bank size (Ah) is divided by battery Ampere-Hour (Ah) which gives a total number of batteries in parallel. The number of batteries in series can be calculated by dividing the system voltage by individual battery voltage. The total number of batteries required is the product of the number of batteries in parallel and the number of batteries in series. If a single battery cannot deliver the required current, multiple batteries should be connected in parallel to meet the required current. The number of batteries to be connected in parallel can be calculated by the following equation, Required battery capacity NBp = Individual battery capacity To obtain the desired system voltage, the number of batteries in series has to be increased. This can be calculated by the following equation, Nominal System Voltage NBs = Nominal Battery Voltage The total number of batteries in the battery bank can be calculated as Nt = NBp * NBs For example, let the total DC energy generated by the solar array be 4,500Wh and this energy must be stored in the battery bank. Being an o-grid system, the autonomy days is 2 days, the depth of discharge is 80%, system eciency is 80% and system voltage is 48V. Then Battery Bank Size = (4,500*2) / (0.8*0.8*48) = 292.96Ah Let us use a 12V battery of 150Ah. The number of battery required in parallel is = 292.96/150 = 1.95 or, ~ 2 nos. of 150Ah batteries Number of the battery connected in series = 48V/12V = 4 nos. Hence total number of batteries = 4 x 2 = 8 nos. 44 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf hxfF, Ah PlDko/ 306fdf Aof6«Lsf] cfsf/ xf] Wh s'n pmhf{ cfjZostf -jf63cfj/ -kfj/ x ;do__ DoA eg]sf] Aof6«Ln] PSn} nf]8 wfGg ;Sg] lbg xf] . ljB'taf6 klg rfh{ x'g] eP !=% lbg lng] t/ ;f]nf/af6 dfq} rfh{ x'g] eP @ lbg lng] . Vs Kofgnsf] ef]N6f]h xf] -!@ ef]N6, @$ ef]N6, $* ef]N6 cflb ._ DoD eg]sf] Aof6«Lsf] s'n Ifdtfdf slt ;Dd l8:rfh{ ug]{ ulx/fO xf] -)=* sf nflu *) k|ltzt l8:rfh{_ Aof6«L a}ª\s cfsf/ k"/f ug{, Aof6«LnfO{ l;l/h jf Kof/fnn /fVg'k5{ . Aof6«L a}ª\ssf] s'n cfsf/ -P Pr_ nfO{ Aof6«L PlDko/3 306fn] efu ug'{k5{, h;n] ;dfgfGt/df nufOPsf] s'n Aof6«Lsf] Kof/fnn ;+Vof lbG5 . l;l/hdf nufOPsf] Aof6«Lsf] ;+Vof u0fgf ug{ l;:6dsf] ef]N6]hnfO{ k|To]s Aof6«Lsf] ef]N6]hn] efu nufpg'k5{ . cfjZos s'n Aof6«Lsf] ;+Vof lgsfNg Kof/fnn / l;l/hdf nufOPsf] Aof6«LnfO{ u'0fg ul/G5 . olb Pp6f Psn Aof6«Ln] cfjZos s/]G6 k|jfx ug{ ;s]g eg] Kof/fnn qmd yk Aof6«Lx? h8fg ug'{k5{ . Kof/fnndf h8fg ug'{kg]{ Aof6«Lsf] ;+Vof lgsfNg tnsf] ;dLs/0f k|of]u ug'{k5{, cfjZos Aof6«L Ifdtf NBp -Pg aLkL_ Ö k|lt Aof6«L Ifdtf k|0ffnLdf ck]lIft ef]N6]h k|fKt ug{, l;l/hdf nufOPsf] Aof6«Lsf] ;+Vof j[l4 ug'{k5{, h'g lgDg ;dLs/0faf6 lgsfNg ;lsG5 . cfjZos l;:6d ef]N6]h NBs -Pg aLP;_ Ö cfjZos Aof6«L ef]N6]h Aof6«L a}ª\sdf /x]sf] Aof6«Lsf] s'n ;+Vof o;/L lgsfNg ;lsG5 M Nt -Pg6L_ Ö NBP -Pg aLkL_ * NBs -Pg aLP;_ pbfx/0fsf nflu, ;f}o{ P/]n] pTkfbg u/]sf] s'n l8;L pmhf{ $,%))Wh 5 / of] pmhf{ Aof6«L a}ª\sdf e08f/0f ug'{k5{ . ckm lu|8 Kofgn ePsf]n] cfTdlge{/ lbg b'O{ lbg x'g cfpF5, l8:rfh{sf] ulx/fO *) k|ltzt xf] . l;:6dsf] sfo{Ifdtf *) k|ltzt / Kofgn ef]N6]h $* ef]N6 5 . ta, Aof6«L a}ª\s cfsf/ Ö -$%))*@)/()=**)=**$*) Ö @(@= (^Ah Pp6f !@ ef]N6sf] Aof6«Lsf] !%) Ah k|of]u u/f}+ . ;dfgfGt/df cfjZos Aof6«L ;+Vof Ö @(@=(^÷!%) Ö !=(% jf, !%) Ah s sf ~@ j6f Aof6«L >[+vnfdf h8fg ul/g] Aof6«Lsf] ;+Vof Ö 48V/12V = 4 nos. -$* ef]N6÷!@ ef]N6 Ö $ j6f_ o;/L Aof6«Lsf] s'n ;+Vof Ö 4 x 2 = 8 nos. -$ x@ Ö * j6f_ 45 Training manual on Solar Irrigation Pumps | Battery Cable Connections The cables that connect batteries play an important part in the performance of the battery bank. Selecting the correct size (diameter) and length of cable is important for the overall system eciency. Cables that are too small or unnecessarily long will result in power loss and increased resistance. When connecting batteries in series and parallel, the cable length interconnecting each battery and to the charge controller or inverter should be of equal length. This ensures that the cable resistance in the positive and negative terminal is the same which allows the battery bank to be uniformly charged. Figure 10 Battery cable connection (National Luna, 2021) All cables in the solar PV system should meet the voltage and current (ampacity), voltage loss, and current loss requirements of the system. For example, the battery cable size (cross-sectional area) and its ampacity (rated current carrying capacity) should be able to carry the maximum current that the cable should be able to carry during charging and discharging. 46 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Aof6«Lsf] tf/ h8fg Aof6«Ldf hf]l8Psf] tf/x?n] Aof6«L a}ª\ssf] ;~rfngdf dxTjk"0f{ e"ldsf lgjf{x u5{ . cfsf/ -Aof;_ / tf/sf] nDafO ;xL rog ug'{ l;:6dsf] ;du| sfo{ Ifdtfsf nflu dxTjk"0f{ x'G5 . cfsf/df Psbd} ;fgf] /x]sf] tf/ jf cgfjZos nfdf] tf/n] kfj/ n; lgDtfpg ;S5 / k|lt/f]w j[l4 u5{ . Aof6L« nfO { l;l/h jf Kof/fnndf h8fg ubf{ k|To]s Aof6«L, rfh{ sG6«f]n/ jf OGe6{/;Fusf] cGt/hl8t tf/ ;dfg nDafOsf] x'g'k5{ . o;n] kf]lhl6e / g]u]l6e 6ld{gndf tf/sf] k|lt/f]w ;dfg /x]sf] ;'lglZrt u5{ h;n] Aof6«L a}ª\snfOP{ sgfzn] rfh{ x'g ;xof]u k'of{pF5 . tl:j/ !) Aof6«Ldf tf/ h8fg -g]zgn n'gf, @)@!_ ;f}o{ lkeL Kofgnsf ;a} tf/x?n] ef]N6]h / s/]G6 -PlDkl;6L_, ef]N6]h n;, / Kofgnsf] s/]G6 n;sf] cfjZostfnfO{ k"/f ug'{k5{ . pbfx/0fsf nflu, Aof6«Lsf] tf/sf] cfsf/ -qm; ;]Szgn Pl/of_ / o;sf] PlDkl;6L -clª\st s/]G6 jxg Ifdtf_ n] rfh{ eO/xFbf / l8:rfh{ ePsf] a]nf clwsQd s/]G6 jxg ug{ ;Sg] x'g'k5{ . 47 Training manual on Solar Irrigation Pumps | Series Connection Batteries are connected in series to add the voltages of individual batteries. The positive terminal of each battery is connected to the negative terminal of the following one. Finally, the negative terminal of the first battery and the positive terminal of the last battery is taken as the output. Figure 11 Batteries in Series (Newenergyco, 2021) Parallel Connection Parallel coupling involves connecting the positive terminals of multiple batteries together and the same with the negative terminals of multiple batteries. This type of arrangement is used to increase the capacity of the battery bank while maintaining the nominal voltage constant. Figure 12 Parallel connection (Newenergyco, 2021) 48 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf l;/Lh h8fg k|To]s Aof6«L a}+ssf] ef]N6]h a9fpg Aof6«Lx? l;l/hdf h8fg ul/G5 . kf]lhl6e 6ld{gn k|To]s Aof6«Lsf] g]u]l6e 6ld{gn;Fu hf]l8G5 . cGTodf, klxnf] Aof6«Lsf] g]u]l6e 6ld{gn / clGtd Aof6«Lsf] kf]lhl6e 6ld{gnnfO{ cfp6k'6sf] ?kdf lnOG5 . $*V rfh{ sG6«f]n/ !@V Aof6«L !@V Aof6«L !@V Aof6«L !@V Aof6«L tl:j/ !! l;l/hdf Aof6«Lx? -g]j]g]{lhsf], @)@!_ Kof/fnn h8fg Kof/fnn slKnª\udf ;a} Aof6«Lx?sf] kf]lhl6e 6ld{gnx? Ps;fy hf]8\g] / ;a} Aof6«Lx?sf] g]u]l6e 6ld{gnx? Ps;fy hl8G5 . o;k|sf/sf] Joj:yf Aof6«L a}ª\ssf] Ifdtf a9fpgsf nflu pRr ef]N6]h l:y/ /fVg k|of]u ul/G5 . !@V rfh{ sG6«f]n/ !@V Aof6«L !@V Aof6«L tl:j/ !@ Kof/fnn h8fg -g]j]g]lh{sf], @)@!_ 49 Training manual on Solar Irrigation Pumps | Series/Parallel Connection A combination of series and parallel connections is required if you need, for example, a 24V battery set using a 12V individual battery and a higher capacity. Figure 13 Series / Parallel Connection (Newenergyco, 2021) Specification Some typical terms used to describe batteries in the market are given below as an example only, " 12V Flooded Lead Acid Battery: capacity ranging from 10Ah to 200Ah " 2V Flooded Lead Acid Battery: capacity ranging from 200Ah to 3,800Ah " 12V VRLA GEL Tubular: capacity ranging from 100Ah to 200Ah " 2V VRLA GEL Tubular: capacity ranging from 200Ah to 4,200Ah 50 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf l;/Lh÷Kof/fnn h8fg l;/Lh / Kof/fnn h8fgsf] ;+of]hg tkfO{nfO{ Tolta]nf cfjZos k5{ ha !@ ef]N6 eGbf dfly ef]N6 / al9 Ifdtf rflxG5 . @$V rfh{ sG6«f]n/ !@V Aof6«L !@V Aof6«L !@V Aof6«L !@V Aof6«L tl:j/ !# l;l/h÷Kof/fnnsf] h8fg -g]j]g]lh{sf], @)@!_ lglb{li6s/0f ahf/df Aof6«Lx? j0f{g ug{ k|of]u ul/Psf s]xL ;fdfGo zAbx? pbfx/0fsf ?kdf tn lbOPsf 5g\ M " !@ ef]N6 Æn8]8 ln8 Pl;8 Aof6«L M !)Ah b]lv @)) Ah ;Ddsf] Ifdtf " @ ef]N6 Æn8]8 ln8 Pl;8 Aof6«L M @)) Ah b]lv #,*)) Ah ;Ddsf] Ifdtf " !@ ef]N6 eLcf/PnP h]n 6\o'an/ M !)) Ah b]lv @)) Ah ;Ddsf] Ifdtf " @ ef]N6 eLcf/PnP h]n 6\o'an/ M @)) Ah b]lv $,@)) Ah ;Ddsf] Ifdtf 51 Training manual on Solar Irrigation Pumps | Example of battery specification Note: The following technical specifications are obtained from Exide Solar Batteries1. Figure 14 Example of technical specification of a battery Charge Controller A charge controller regulates the energy from the solar array and charges the battery bank. It is similar to the voltage regulator and regulates the voltage and current from the solar panels to safely charge the battery bank. Battery life reduces drastically due to overcharging and deep discharging hence it is necessary to protect the battery from being overcharged or deeply discharged. The primary purpose of the charge controller is to prevent the battery from overcharging and deep discharging. 1 https://docs.exideindustries.com/pdf/products/solar-batteries/solar-all-product-catalogue.pdf, Accessed 2021, November, 25 52 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Aof6«L lglb{li6s/0f -:k]l;lkms]zg_ sf pbfx/0fx? gf]6M PS;fO8 ;f}o{ Aof6«Laf6 lgDg adf]lhdsf k|fljlws lglb{li6s/0f k|fKt ul/Psf] 5 .1 tl:j/ !$ Aof6«Lsf] k|fljlws lglb{li6s/0fsf] pbfx/0f rfh{ sG6«f]n/ Pp6f rfh{ sG6«f]n/n] ;f}o{ P/]af6 cfPsf] pmhf{nfO{ lgoGq0f / Aof6«L a}ª\snfO{ rfh{ u5{ . of] ef]N6]h /]Uo'n]6/ h:t} xf] / Aof6«L a}ª\snfO{ ;'/lIft rfh{ ug{ ;f}o{ Kofgnaf6 cfPsf] ef]N6]h tyf s/]G6sf] lgoGq0f u5{ . cfjZostfeGbf a9L rfh{ ubf{ / l/lQg] u/L l8:rfh{ ul/g'n] Aof6«Lsf] cfo' 36fpF5 To;}n] Aof6«LnfO{ oL b'a} cj:yfaf6 hf]ufpg cfjZos x'g hfG5 . rfh{ sG6«f]n/sf] d'Vo p2]Zo Aof6«LnfO{ cToflws rfh{ / l/lQg] u/L l8:rfh{ x'g] cj:yfaf6 /f]Sg' xf] . 1 https://docs.exideindustries.com/pdf/products/solar-batteries/solar-all-product-catalogue.pdf, Accessed 2021, November, 25 53 Training manual on Solar Irrigation Pumps | Figure 15 PV System with a Charge controller (Synergy, 2021) The charge controller takes battery voltage as a reference to determine its state of charge and stops charging when the battery bank voltage has reached its high level. The charge controller resumes charging when the battery bank voltage drops as it powers the load. The following tashowse of the battery status during charging and discharging. The following table shows the state of charge of a nominal 12V battery at dierent battery voltages. Note: The following table is for general reference only and does not apply to all batteries. Battery voltage (volts) State of charge Above 13V 100% 12V 67% 11V 34% Below 10V 1% 54 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Aof6«L OGe6{/ nf]8\; kmf]6f]ef]N6flos Kofgn rfh{ sG6«f]n/ tl:j/ !% Pp6f rfh{ sG6«f]n/;lxtsf] lkeL Kofgn -l;ghL{, @)@!_ rfh{ sG6«f]n/n] Aof6«L ef]N6]hnfO{ o;sf] rfh{sf] cj:yf lgwf{/0f ug]{ ;Gbe{sf] ?kdf lnG5 / Aof6«L a}ª\s ef]N6]h pRr :t/df k'Ubf rfh{ ug{ /f]S5 . Aof6«L a}ª\s ef]N6]h 36]kl5 rfh{ sG6«f]n/n] rfh{ ug{ k'gM ;'? u5{ . tnsf] tflnsfn] rfh{ x'g] qmddf / l8:rfh{ ePsf] a]nf Aof6«Lsf] cj:yfsf] pbfx/0f atfpF5 . tnsf] tflnsfn] ljleGg Aof6«L ef]N6]hdf ;fdfGo !@ ef]N6sf] Aof6«Lsf] rfh{sf] cj:yf b]vfpF5 . gf]6 M tnsf] tflnsf ;fdfGo ;Gbe{sf nflu dfq} pko'Qm 5g\ / ;a} Aof6«Lsf nflu nfu" x'Gg . Aof6«L ef]N6]h -ef]N6\;_ rfh{sf] cj:yf !# ef]N6dfly !)) % !@ ef]N6 ^&% !! ef]N6 #$% !) ef]N6 d'lg ! % 55 Training manual on Solar Irrigation Pumps | Types of Charge Controller Generally, there are two types of charge controllers in use: non-MPPT charge controller and MPPT charge controller. Non-MPPT Charge Controller Non-MPPT charge controller operates by making a direct connection from the solar panel to the batteries, and thus, the solar array voltage is referenced to the battery voltage. The battery voltage adjusts slightly depending on the current generated by the panel and the characteristics of the batteries. Generally, the non-MPPT charge controller rarely operates at the V of the solar panel, potential energy is being wasted that could otherwise be used to better charge MAX the battery bank and maintain system power. The greater the dierence between battery voltage and the V of the MAX panel, the more energy is wasted and reduces the eciency of the system. MPPT Charge Controller A Maximum Power Point Tracker (MPPT) is an electronic DC to DC converter that maximizes the available power from the solar panels at any instance by optimizing the charging voltage and current between the solar panels and the battery bank. Generally, it can provide a power gain of up to 33% compared to non-MPPT controllers. Charge Controller Features Following are some important features of a charge controller: " Electronic blocking (to protect against reverse polarity connection of PV panel and block current from the battery to PV panel when the battery is overcharged), " Rated charging/load current, " PWM Charging with 3-stage Charge Control (to allow the battery to be left unattended for long period), " User adjustable charge control settings for dierent types of batteries, " User Adjustable Low Voltage Disconnect and Low Voltage Reconnect, " Built-In Microprocessor for PV charge control to maximize the charging eciency, overcharge and over-discharge protection " Over-temperature protection, " Short-circuit protection at load terminal & battery reverse polarity protection at battery connection terminal, " Informative LCD Display and tri-color LED indication of system and battery conditions, optional temperature sensor for compensated battery charging, " Optional remote signal terminal. 56 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf rfh{ sG6«f]n/sf] k|sf/x? ;fwf/0ftof, b'O{ k|sf/sf rfh{ sG6«f]n/x? k|of]udf 5g\ M u}/3PdkLkL6L rfh{ sG6«f]n/ / PdkLkL6L rfh{ sG6«f]n/ . u}/3PdkLkL6L rfh{ sG6«f]n/ -PdkLdL6L gePsf]_ u}/3PdkLkL6L rfh{ sG6«f]n/ ;f}o{ Kofgnsf] Aof6«L;Fu k|ToIf h8fg eP/ ;~rfng x'G5 / o;k|sf/, ;f}o{ P/] ef]N6]hsf] ;Gbe{ Aof6«L ef]N6]hnfO{ dflgG5 . Aof6«L ef]N6]h, Kofgnåf/f pTkGg s/]G6 / Aof6«Lsf] ljz]iftfx?df lge{/ eO{ ;Gt'lnt x'G5 . ;fwf/0ftof, u}/3PdkLkL6L rfh{ sG6«f]n/n] ;f}o{ Kofgnsf] Vmax df lj/n} sfd u5{, v]/ uO/x]sf] ;Defljt pmhf{ Aof6«L a}ª\snfO{ /fd|f];Fu rfh{ ug{ / Kofgnsf] kfj/ sfod /fVg k|of]u ug{ ;lsG5 . Aof6«L ef]N6]h / Kofgnsf] eLDofS; aLrsf] leGgtf hlt a9L eof] Tolt g} pmhf{ v]/ hfG5 / Kofgnsf] sfo{Ifdtf sd x'G5 . PdkLkL6L rfh{ sG6«f]n/ Pp6f clwsQd kfj/ KjfOG6 6«ofs/ -PdkLkL6L_ Ps ljB'tLo l8;Laf6 l8;L ?kfGt/s xf] h;n] s'g} ;do ;f}o{ Kofgnaf6 pknAw kfj/nfO{ ;f}o{ Kofgn / Aof6«L a}ª\ssf] aLrdf rflh{ª\u ef]N6]h / s/]G6nfO{ cg's"n agfP/ clwsQd agfpF5 . ;fwf/0ftof, o;n]] u}/ PdkLkL6L sG6«f]n/sf] ck]Iff ## k|ltzt;Dd kfj/ nfe u/fpg ;S5 . rfh{ sG6«f]n/sf ljz]iftfx? rfh{ sG6«f]n/sf lgDg dxTjk"0f{ ljz]iftfx? 5g\ M " On]S6«f]lgs cj/f]w -lkeL Kofgnsf] pN6f] w'|jLo -Polarity_ h8fgaf6 hf]ufpg / Aof6«L cf]e/rfh{ x'Fbf Aof6«Laf6 lkeL Kofgndf k|jfx /f]Sg_, " rfh{÷s/]G6 nf]8 d"Nofª\sg u5{, " tLg r/0fdf rfh{ lgoGq0f ug'{sf ;fy} kLPd8ANo' rflh{ª\u -Aof6«LnfO{ nfdf] cjlwsf nflu Wofg glbO{ pk]lIft ug{ cg'dlt lbg_, " ljleGg k|sf/sf Aofl6«sf nflu o"h/ P8h:6]an rfh{ sG6«f]n ;]l6ª\u, " sd ef]N6]hdf ljR5]bg / sd ef]N6]hdf k'gM h8fg ug{ k|of]ustf{nfO{ ;dfof]Ho, " dfOqmf]k|f];];/df lgld{t ePsf]n] rflh{ª\u Ifdtf, cf]e/rfh{ / cf]e/3l8:rfh{ clwsQd agfpg lkeL rfh{ lgoGq0fdf ;'/lIft /fV5, " clwsQd tfkqmdaf6 ;'/Iff, " nf]8 w|'j -terminal_ df ;6{ ;ls{6 ;'/Iff / Aof6«L h8fg w|'j -terminal_ df Aof6«L pN6f] w|'jLo -Reverse Polarity_ ;'/Iff, " ;"rgfTdsg Pn;L8L l8:Kn] / Kofgn Pjd\ Aof6«Lsf] cj:yfsf] lq/ª\uLo PnO8L ;+s]t, Aof6«L rflh{ª\usf nflu Ifltk"lt{o'Qm j}slNks tfkdfg ;]G;/, " j}slNks l/df]6 ;+s]t w|'j . 57 Training manual on Solar Irrigation Pumps | Specification of Charge Controller If maximum charging capacity is only a factor to be considered, the MPPT charge controller is the best choice. Normally, specifying a PV charge controller depends on site conditions, system components, size of the panel and load, and finally the cost for a particular solar power system. MPPT charge controllers are relatively more costly than non-MPPT charge controllers. The below table shows an example technical specification of a Xantrex charge controller2. Figure 16 Example technical specification of a charge controller 2 http://www.xantrex.com/documents/Solar/20191122_XantrexSolar_MPPT_ChargeController2019.pdf, Accessed 2021, December, 1 58 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf rfh{ sG6«f]n/sf] lglb{li6s/0f obL clwsQd rflh{ª\u Ifdtf Pp6f dfq} sf/s /x]sf] dflgG5 eg], PdkLkL6L rfh{ sG6«f]n/ ;a}eGbf pTs[i6 5gf}6 xf] . ;fdfGotof, lkeL rfh{ sG6«f]n/ ljlzli6s[t ug'{ :ynsf] cj:yf, k|0ffnLsf sDkf]g]G6, Kofgnsf] cfsf/ / nf]8, / cGTodf ljz]if ;f}o{ phf{ k|0ffnLsf] d"Nodf lge{/ x'G5 . PdkLkL6L rfh{ sG6«f]n/x? PdkLkL6L gePsf] rfh{ sG6«f]n/ eGbf dxFuf] x'G5 . pbfx/0fsf nflu tnsf] tflnsfn] h]G6«]S;sf] rfh{ sG6«f]n/sf] k|fljlws lglb{li6s/0f bzf{p52 tl:j/ !^ Pp6f rfh{ sG6«f]n/sf] k|fljlws lglb{li6s/0f ;lxtsf] pbfx/0f 2 http://www.xantrex.com/documents/Solar/20191122_XantrexSolar_MPPT_ChargeController2019.pdf, Accessed 2021, December, 1 59 Training manual on Solar Irrigation Pumps | Sizing a Charge Controller The charge controller sizing involves the following formula and in this step, calculate the short circuit current of PV module and then charge controller minimum power current: Charge Controller Size= Isc*N*Safety Factor Where, I is the short circuit current of the solar array SC N is the number of modules connected in parallel Safety Factor can be taken to be 1.25 for non-MPPT and 1.33 for MPPT Note: This is a general sizing method only. Safety factors are specific to site requirements. Next, the input voltage range of the charge controller must accept the solar array configuration voltage. 60 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf rfh{ sG6«f]n/sf] ;fOlhª rfh{ sG6«f]n/sf] cfsf/Ls/0fdf lgDg ;"q ;dfj]z x'G5 . o; k|s[ofdf lkeL ;+/rgfsf] 5f]6f] kl/ky -z6{ ;ls{6_ s/]G6sf] u0fgf ug'{xf];\ / To;kl5 rfh{ sG6«f]n/sf] Go'gQd kfj/ s/]G6 u0fgf ug'{xf];\ M rfh{ sG6«f]n/ cfsf/ Ö Isc * N * ;'/Iff sf/s hxfF, &IscÚ ;f}o{ ;/0fLsf] ;6{ ;ls{6 s/]G6 xf]] &NÚ Kof/fnndf h8fg ul/Psf] ;f}o{ Kofgnx?sf] ;+Vof xf] ;'/Iff sf/s PdkLkL6L gePsf nflu !=@% / PdkLkL6Lsf nflu !=## lng ;lsG5 . gf]6M of] Pp6f ;fwf/0f cfsfl/s/0f k|s[of xf] . ;'/Iff sf/sx? :yn -;fO6_ sf] cfjZostf adf]lhd ljlzi6 x'G5 . rfh{ sG6«f]n/sf] OGk'6 ef]N6]h bfo/fn] ;f}o{ P/]sf] ef]N6]hnfO{ :jLsf/ ug'{k5{ . 61 Training manual on Solar Irrigation Pumps | Inverter An inverter converts the direct current (DC) into alternating current (AC). It allows the use of ordinary AC-powered equipment. Generally, inverters use the principle of Pulse Width Modulation (PWM) to produce output, which may be a variable voltage or variable frequency supply. DC CURRENT INVERTER AC CURRENT Types of Inverters O-Grid Inverter O-grid inverters are used in a stand-alone system intended to operate independently of the electricity grid. A general schematic of the o-grid system with an inverter is shown below. Figure 17 Schematic of o-grid system with inverter (Solarreviews, 2021) Hybrid inverter  Hybrid Inverters are sometimes referred to as multi-mode inverters, which is an inverter that can simultaneously manage inputs from both solar panels and a battery bank, charging batteries with either solar array or the electricity grid. 62 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf OGe6{/ OGe6{/n] 8fO/]S6 s/]G6 -l8;L_ nfO{ cN6/g]l6ª s/]G6 -P;L_ df ?kfGt/0f u5{ . o;n] ;fwf/0f P;L3;~rflnt pks/0fsf] pkof]unfO{ cg'dlt lbG5 . ;fwf/0ftof, OGe6{/x?n] cfp6k'6 pTkfbg ug{ &kN; lj8\y df]8\o'n]zgÚ -kLPd8ANo'_ l;4fGt k|of]u u5{, h'g Pp6f kl/jt{gzLn ef]N6]h cyjf kl/jt{gzLn cfj[lQ -lk|mSj]G;L'_ x'g ;S5 . l8;L s/]G6 OGe6{/ P;L s/]G6 OGe6{/sf k|sf/x? ckm3lu|8 OGe6{/ ckm3lu|8 OGe6{/sf] k|of]u ljB't lu|8af6 :jtGq ?kn] ;~rflnt ug]{ p2]Zon] Ps :6\ofG83cnf]g k|0ffnLdf k|of]u ul/G5 . OGe6{/;Fu} ckm3lu|8 Kofgnsf] ;fdfGo of]hgf tn b]vfOPsf] 5 . ;f}o{ Kofgn cf]K;gn h]g]/]6/ rfh{ sG6«f]n/ OGe6{/ 3/ Aof6«L a}+s tl:j/ !& OGe6{/;Fu} ckm3lu|8 Kofgnsf] ;fdfGo of]hgf -;f]nf/ l/Eo'h, @)@!_ xfOla|8 OGe6{/ xfOla|8 OGe6{/x?nfO{ slxn]sflx+ ax'3df]8 OGe6{/x? elgG5, h;n] ;f}o{ Kofgnx? / Aof6«L a}ª\s b'j}af6 OGk'6x? Joj:yfkg ug{ ;S5, of t ;f}o{ P/] jf ljB't lu|8af6 Aof6«Lx? rfh{ u5{ . 63 Training manual on Solar Irrigation Pumps | Figure 18 Schematic of Hybrid Inverter (Solarreviews, 2021) Grid-tied inverter  Grid tied-inverter converts direct current (DC) from the solar array into alternating current (AC) that can be directly injected into the power grid. For reference, the single-phase voltage and frequency standard in Nepal is 230V RMS at 50Hz. In this system, energy from the solar array is used for self-consumption (residential or commercial applications) and any excess or deficit energy is exported or imported from the electricity grid. Figure 19 Schematic of Grid-tied power inverter (Solarreviews, 2021) 64 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;f}o{ Kofgnx? P;L Aof6«L ljB't lu|8 ld6/ 3/ OGe6{/ tl:j/ !* xfOla|8 OGe6{/sf ;fdfGo of]hgf -;f]nf/ l/Eo'h, @)@!_ lu|836fO8 OGe6{/ lu|836fO8 OGe6{/n] ;f}o{ P/]af6 cfPsf] 8fO/]S6 s/]G6 -l8;L_ nfO{ cN6/g]l6ª s/]G6 -P;L_ df ?kfGt/0f u5{ h'g ljB't lu|8df l;w} hf]8\g ;lsG5 . ;Gbe{sf] nflu, g]kfndf Psn3km]h ef]N6]h / lk|mSj]G;L dfgs 50Hz df 230V RMS xf] . o; k|0ffnLdf, ;f}o{ P/]af6 cfPsf] pmhf{nfO{ :j3vktdf k|of]u ul/G5 -cfjf;Lo jf Joj;flos pkof]u_ / s'g} klg cltl/Qm jf 36L x'g] pmhf{nfO{ ljB't lu|8af6 lgof{t jf cfoft ul/G5 . ld6/ ljB't lu|8 ;f}o{ Kofgn OGe6{/ 3/ tl:j/ !( lu|836fO8 OGe6{/sf] ;fdfGo of]hgf -;f]nf/ l/Eo'h, @)@!_ 65 Training manual on Solar Irrigation Pumps | Inverter Sizing The sizing of the inverter can be done using the formula below. The DC voltage input for the inverter must be compatible with the charge controller and the battery bank. Inverter ( Watt/ kVA) = Total power (W) X safety factor Where, Total Power = Peak instantaneous power of the load Safety Factor = 1.25 (as general reference) Note: This is a general sizing method only. Safety factors are specific to site requirements. Specification of an inverter The important features of inverters for solar PV applications are: " Nominal input voltage of DC " Nominal output voltage of 230V AC (single-phase), or 400V AC (three-phase) " Designed rating " Optimally suited range " Peak eciency factor of > 98% " Module and its importance " MPPT range " Programming facility " Positioning functionality " Display of monitored current and voltage " Compact solution based on overall space and cost " Data monitoring/ remote control via Ethernet/network integration/vector control etc. 66 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf OGe6{/sf] ;fOlhª OGe6{/sf] cfsf/ lgwf{/0f tnsf] ;"q k|of]u u/]/ ug{ ;lsG5 . OGe6{/sf nflu l8;L ef]N6]h OGk'6 rfh{ sG6«f]n/ / Aof6«L a}ª\s;Fu d]n vfg] x'g'k5{ . OGe6{/ ( Wat/ kVA) = s'n kfj/ (W) X ;]Æ6L ÆofS6/ hxfF, s'n kfj/ -Total Power_ Ö nf]8sf] tfTsflns kfj/ ;]Æ6L ÆofS6/ -Safety Factor_ Ö !=@% -;fdfGo ;Gbe{sf nflu_ OGe6{/sf] lglb{li6s/0f ;f}o{ lkeL pkof]usf nflu OGe6{/sf] dxTjk"0f{ ljz]iftfx? M " l8;Lsf] gf]ldgn OGk'6 ef]N6]h " P;L l;+un km]hsf nflu gf]ldgn ef]N6]h @#) ef]N6 jf $)) ef]N6 P;Lsf nflu -tLg km]h_ " l8hfOg ul/Psf] /]l6+u " pko'Qm pTs[i6 bfo/f " pRrQd kfj/ bIftf >(* k|ltzt a9L " Kofgn / o;sf] dxTj " PdkLkL6L -MPPT_ bfo/f " k|f]u|fldª\u ;'ljwf " l:ylt lgwf{/0f Ifdtf " lgodg ul/Psf] ef]N6]h / s/]G6sf] l8:Kn] " ;du| :yfg / d"Nosf] cfwf/df sDKofS6 -;fgf] 7fpF vfg]_ ;dfwfg " Oy/g]6÷PsLs[t ;~hfn -g]6js{_÷e]S6/af6 tYofª\s lgodg÷l/df]6 sG6«f]n OToflb . 67 Training manual on Solar Irrigation Pumps | An example of an inverter datasheet for solar PV application is given in the figure below. Note: The following technical specifications are obtained from the EssenSolar inverter datasheet3. Figure 20 Example of a technical specification of an inverter 3 https://www.fsp-group.com/download/pro/EssenSolar1k3k5k_Datasheet.pdf, Accessed 2021, November, 25 68 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;f}o{ lkeL PKnLs]zgsf nflu OGe6{/ 8f6flz6sf] pbfx/0f tnsf] tl:j/df lbOPsf] 5 . gf]6M tnsf] k|fljlws lglb{li6s/0f P:;}g;f]nf/ OGe6{/ 8f6flz6af6 k|fKt ePsf] 5 .3 tl:j/ @) OGe6{/sf] k|fljlws lglb{li6s/0fsf] pbfx/0f 3 https://www.fsp-group.com/download/pro/EssenSolar1k3k5k_Datasheet.pdf, Accessed 2021, November, 25 69 Training manual on Solar Irrigation Pumps | Section II: Solar Irrigation Pump 70 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf v08 @M ;f}o{ l;+rfO kDk 71 Training manual on Solar Irrigation Pumps | 4. Introduction Solar Water Pumping (SWP) systems have been used commonly for irrigation, livestock watering, and even in town water supply systems. Solar Irrigation Pump (SIP) is an application of the SWP system used mostly in irrigating paddy fields and vegetables, and watering gardens among others. Some advantages of a typical solar irrigation system are: 1 Makes irrigation possible in remote areas where there is no/limited access to the grid 2 Is environment-friendly 3 No grid connection is required and no electricity bills need to be paid 4 No fuel is required; hence the cost of operation is very low 5 Is durable, requiring minimal maintenance The major components of a typical solar-powered pumping system include a solar array that powers a submersible or surface pump. The solar array capacity of the SIP is dependent on the size of the pump chosen for the desired water output at the desired vertical head. The water may be pumped from a bore well, open well, stream, pond, and other water sources to a storage tank ,or, the water can be directed to the field. The SIP system has three major components: pump, controller, and solar panels. A typical example of an SWP or SIP system is shown in Figure 21. The pump is driven by a motor which is powered by the electricity generated by the solar panel. The motor can be AC or DC. Most DC pumps run at 24 volts rather than 12 volts. However, smaller systems for 12 volts do exist for light- duty applications, while systems running on 48 volts also exist for heavier applications. As for AC, pumps rated at 230V or 400V are available for Nepal’s market. The power of a motor is specified in either watt (W) or horsepower (HP). Figure 21 Overview of the Solar Water Pump system: Submersible pump (Top) and Surface Pump (Bottom) 72 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf $= kl/ro ;f}o{ kDk k|0ffnL ;fdfGotof l;+rfO, ufO{j:t'nfO{ kfgLsf] cfjZostf k"lt{ ug{, / zx/L kfgL cfk"ltk{ |0ffnLdf ;d]t k|of]u ul/G5 . ;f}o{ l;+rfO kDk eg] clwsf+z wfg v]t / t/sf/L tyf au}+rfdf kfgL xfNg k|of]u ul/G5 . ;fdfGo ;f}o{ l;+rfO k|0ffnLsf s]xL kmfObfx? lgDg cg';f/ 5g\ M != lu|8;Dd kx'Fr gePsf] jf lu|8df ;Lldt kx'Fr ePsf] b'u{d If]qdf l;+rfO ;Dea agfpF5 . @= jftfj/0fd}qL xf] . #= lu|8df h8fgsf] cfjZostf x'Gg / lah'nL lan ltg{ cfjZos x'Gg . $= OGwg cfjZos x'Gg, To;}n] ;~rfng vr{ cToGt} Go"g x'G5 . %= l6sfp x'G5, Go'gQd dd{t cfjZos x'G5 . Pp6f ;fdfGo ;f}o{3;~rflnt klDkª\ k|0ffnLsf] k|d'v k|sf/x?df ;f}o{ P/] ;dfj]z x'G5 h;n] ;adl;{an kDk jf ;km]{; kDknfO{ pmhf{ lbG5 . ;f}o{ kDksf] ;f}o{ P/]sf] Ifdtf ck]lIft kfgL tfGgsf nflu rog ul/Psf] kDksf] cfsf/df lge{/ x'G5 . kfgL, tnfp, v'nf Ogf/, vf]nf, kf]v/L / cGo kfgLsf ;|f]tx?af6 e08f/0f 6ofª\sLdf kDk ug{ ;lsG5 jf v]tdf k7fpg ;lsG5 . ;f}o{ kDk l;:6dsf] tLg k|d'v efux? 5g\ M kDk, sG6«f]n/ / ;f}o{ Kofgn . ;f}o{ kDk l;:6dsf] ;fdfGo pbfx/0f tl:j/ @! df b]vfOPsf] 5 . kDk df]6/af6 ;~rflnt x'G5 h;nfO{ ;f}o{ Kofgnn] pTkfbg u/]sf] lah'nLaf6 pmhf{ k|fKt x'G5 . df]6/ P;L jf l8;L s'g} x'g ;S5 . clwsf+z l8;L kDk @$ ef]N6df rfn" x'G5 g sL !@ ef]N6df . o2kL, ;fgf pks/0fx?sf nflu !@ ef]N6sf] ;fgf k|0ffnLx? ljBdfg 5g\ hasL 7"nf pks/0fsf nflu $* ef]N6sf] k|0ffnL ;d]t ljBdfg 5 . P;Lsf nflu @#) ef]N6b]lv $)) ef]N6;Dd Ifdtfsf] kDk g]kfnL ahf/df pknAw 5g\ . df]6/sf] kfj/ jf6 -W_ of xf];{kfj/ -HP_ df pNn]v ul/Psf] x'G5 . Tl:j/ @! ;f}o{ jf6/ kDk k|0ffnLsf] ljj/0f M ;adl;{an kDk -dfly_ / ;km]{; kDk -tn_ 73 Training manual on Solar Irrigation Pumps | 5. Basic Steps in System Design The general approach to designing a system can be summarized as follows: i. Determine the volume of water to be pumped each day and verify the discharge rate ii. Determine the total dynamic head iii. Calculate the pump’s rated power and discharge capacity manually and verify with the selected company’s performance chart iv. Select the pump referring to pump performance curves of reputed manufacturers v. Select the appropriate size of solar PV modules considering losses and eciency vi. Select a compatible controller that regulates power from the solar array and drives the pump However, before following these guidelines, it is helpful to ascertain whether a directly coupled system (no batteries, no external controller, or power conditioning circuitry) is feasible for the particular application. If so, such a system is strongly recommended, even though its use provides little flexibility in component choice and system configuration. However, there are occasions when directly coupled systems are unsuitable. These include: " When pumping heads are too large to use a centrifugal pump with reasonable eciency; " When suitable DC motors are not available, such as with some large systems (greater than 10 HP) where little choice exists, or when a submersible motor is necessary and no brushless DC motors are available at a suitable price; " When batteries must be used for energy storage (i.e. where “availability” of pumped water must be very high and tank storage is unsuitable) e.g. portable units; " Where locations characterized by excessive cloudy weather make the poor part-load eciencies of a directly coupled system unacceptable. General Head Calculation The Total Dynamic Head (TDH) is the total vertical height that the pump has to push water that takes into account all losses. TDH is calculated as TDH=Delivery head + Suction Head + Head due to friction loss Where, Delivery head is the total vertical head the water travels from the pump level to the top of the tank; Suction head is the head required to lift the water from the source to the pump level When the total pumping head is very high, appropriate sizing of pump and solar array may become a challenge to pump in one stage. In such a case multi-stage pumping can be done where a single large SIP is divided into two or more SIPs operating as a cascading system. When staging pumping stations, technical and economic analyses are to be done. In high head, appropriate material and thickness of pipes and non-return value fittings need to be chosen to protect the pump from water hammer pressure. 74 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf %= l;:6d l8hfOgsf] cfwf/e"t r/0fx? Kofgn l8hfOgsf] ;fdfGo b[li6sf]0fnfO{ ;+If]kdf lgDgfg';f/ ug{ ;lsG5 M != k|To]s lbg kDk ug'{kg]{ kfgLsf] dfqf lgwf{/0f ug'{k5{ / kfgLsf] lgj{xg b/ k|dfl0ft ug'{k5{ . @= s'n 8fogflds x]8 lgwf{/0f ug'{k5{ . #= kDksf] d"Nofª\sg kfj/ / l8:rfh{ Ifdtf u0fgf ug'{k5{ / rog ul/Psf] sDkgLsf] kkm{d]G; rf6{;Fu 7Ls 5 ls 5}g\ x]g'{k5{ . $= k|ltli7t lgdf{tfx?sf] kDk k/km/d]G; se{nfO{ ;Gbe{ ug]{ kDk rog ug'{k5{ . %= n; / kfj/ bIftfnfO{ Wofgdf /fv]/ ;f}o{ lkeL Kofgnx?sf] pko'Qm cfsf/ rog ug'{k5{ . ^= s'g} cg's"n sG6«f]n/nfO{ rog ug'{k5{ h;n] ;f}o{ P/]af6 pmhf{ lgolGqt u/]/ kDk ;~rfng u5{ . o2kL, oL lgb]{zgx? kfngf ug'{k"j{ Aof6«L/lxt, aflxl/ sG6«f]n/ljxLg jf kfj/ slG8l:gª\u ;ls{6/L lagfsf] l;:6d ;Dea 5 jf 5}g\ eGg] lglZrt x'g' h?/L x'G5 . olb ldN5 eg], To:tf k|0ffnLnfO{ lgjf{b l;kmfl/z ul/G5, o2kL o;sf] k|of]un] k|sf/ 5gf}6 / Kofgn ;+/rgfdf yf]/} nlrnf]kg k|bfg u5{ . t/ 8fO/]S6 -Direct_ hf]l8Psf] k|0ffnL o:tf dfldnfdf pko'Qm x'Fb}gg\ . " klDkª\u x]8x? ;]lG6«km\o'un kDksf] k|of]u u/]/ plrt sfo{Ifdtf lbg cToflws 7"nf] x'Fbf . " pko'Qm l8;L df]6/ pknAw gx'Fbf, h:t} s]xL 7"nf] k|0ffnL -!) PrkL clws_ hxfF yf]/} dfq ljsNk ljBdfg x'G5,j f ;adl;{an df]6/ cfjZos x'Fbf jf s'g} a|zn]; l8;L df]6;{ pko'Qm d"Nodf pknAw gePsf] cj:yfdf . " Aof6«L pmhf{ e08f/0fsf nflu k|of]u ug'{kg]{ ePdf -kDk ul/Psf] kfgLsf] pknAwtf cToflws x'g'kg]{ jf 6\ofª\ssf] e08f/0f cg'ko'Qm ePdf_ pbfx/0fsf nflu kf]6]{an o"lg6\; . " cToflws afbn nfUg] df};d x'g] :yfgx?n] k|ToIf ?kdf hf]l8Psf] k|0ffnLsf] sdhf]/ nf]8 Ifdtfx?nfO{ c:jLsfo{ agfpFbf . ;fwf/0f x]8 u0fgf s'n 8fogflds x]8 -6L8LPr_ eGgfn] kDkn] kfgL ws]Ng kg]{ s'n 7f8f] prfO{ xf] h;n] ;a} n;nfO{ Wofgdf /fV5 . 6L8LPr o;/L u0fgf ul/G5 6L8LPr Ö 8]lnel/ x]8 ± ;Szg x]8 ± 3if{0f -Fric}on_ n] x'g] x]8 n; hxfF, 8]lnel/ x]8 eg]sf] kfgLsf] ;txaf6 6ofª\sLsf] dfly;Ddsf] s'n prfO{ xf] . kfgLsf] ;txaf6 kDk n]en;Dd kfgL tfGg] prfO{ &;Szg x]8Ú xf] . s'n klDkª\u x]8 w]/} pRr ePdf kDk / ;f}o{ P/] sf] pko'Qm cfsf/ Ps r/0fdf kDk ug{ r'gf}tLk"0f{ x'g;S5 . o:tf] cj:yfdf ax'3r/0f klDkª\u ug{ ;lsG5 hxfF Pp6f Psn 7"nf] ;f}o{ kDknfO{ b'O{ jf a9L ;f}o{ kDkdf ljeflht ul/G5 h'g Sof:s]l8ª\u k|0ffnLsf] ?kdf ;~rfng x'G5 . klDkª :6]zgx¿ :6]lhª ubf{, k|fljlws / cfly{s ljZn]if0f ug{'k5{ . kDksf] kfgLnfO{ cToflws bafaaf6 hf]ufpg xfO x]8df pko'Qm ;fdu|L jf kfOksf] df]6fO jf gg\3l/6g{ eNe lkml6+u ug'{k5{ . 75 Training manual on Solar Irrigation Pumps | Figure 22 Vertical measurements of surface pump systems Choice of Pump Surface Centrifugal pump As the name suggests, the surface pump is normally placed at ground level and is suitable for pumping from shallow bore wells, open wells, reservoirs, lakes, and canals. Surface pumps are generally suitable for regions where the water level is within 5-7m below ground level due to the limitation of the suction head. Figure 23 Typical Surface Centrifugal Pumps (Pedrollo, 2021) A typical surface centrifugal pump is shown in Figure 23 which is relatively cheap and is readily available in the market. Surface centrifugal pumps are usually designed for high flow rates and low heads. They are usually made of cast iron and are finished with an anti-corrosive primer, followed by silver-coloured polyurethane paint. These pumps may be damaged if they are run dry for a long period and needs a priming mechanism. 76 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf 6ofª\s el6{sn /fOh\ :6]l6s u|fpG8 n]en klDkª ulx/fO n]jn 8«g8fpg af]/ j]n ulx/fO{ ;adh]{G; kDk ulx/fO{ tl:j/ @@ kfgLsf] ;txaf6 7f8f] gfkx? kDksf] 5gf]6 ;km]{; ;]lG6«km\o'un kDk gfdn] ;'emfP h:t}, ;km]{; kDk ;fdfGotof hdLgsf] txdf /flvG5 / sd ulx/f] s'jf -z}nf] af]/ j]n_, v'nf Ogf/, hnfzo, tfn / gx/x?af6 kDk ug{ pko'Qm x'G5 . ;km]{; kDkx? tL If]qsf nflu pko'Qm x'G5 hxfF ;Szg x]8sf] ;Lldttfsf sf/0f kfgLsf] :t/ hdLgsf] ;txeGbf kfFr3;ft ld6/ leq x'G5 . tl:j/ @# ;km]{; ;]lG6«km\o'un gd"gf kDk -k]8«f]nf], @)@!_ Pp6f gd"gf ;txdf cfwfl/t ;km]{; kDk tl:j/ @# df b]vfOPsf] 5 h'g t'ngfTds ?kdf ;:tf] / ahf/df ;lhn} pknAw x'G5 . ;txdf cfwfl/t ;km]{; kDk k|foh;f] pRr axfj b/ / nf} x]8x?sf nflu l8hfOg ul/Psf] xf] . ltgLx? ;fdfGotof 9nf}6] -sRrf_ kmnfdaf6 ag]sf x'G5g\ / lvof nfUg glbg] n]kg -k|fOd/_ nufOPsf] x'G5, To;kl5 rfFbL /ª\usf] kf]nLo"/]y]g k}G6 x'G5 . o:tf] kDknfO{ kfgL tfGg' cufl8 k|fOd ug{ h?/L x'G5 . 77 Training manual on Solar Irrigation Pumps | Submersible pump As the name suggests, a submersible pump is immersed in water. It pumps water by displacement and is mostly used in deep wells. Such type of pumps is designed for high head and medium flow application. They are multi-stage pump and has high-eciency micro-computer-based inverter. The inverter optimizes the power input and thus enhances the overall system eciency. These pumps are relatively costly compared to surface pumps but have a longer life and greater reliability than surface pumps. Figure 24 Typical Submersible Pumps (Pedrollo, 2021) Table 1 Comparison of surface and submersible pumps Surface pumps Submersible pumps " Needs to be primed " Doesn’t need to be primed " More prone to theft as they are above " Less prone to theft ground " Less prone to wear and tear due to " More prone to wear and tear due to environmental eects environmental eects " Dicult to remove once installed " Easy to access for repair and maintenance " Requires major overhaul maintenance and " Parts are more easily available in the possible rewinding of coil approximately local market (in Nepal’s scenario), and by every 5 years doing so the lifetime of the pump can be extended " Submersible pumps usually last a long time, since they are made of stainless steel. General Overview of SIPs Installation Site selection Selecting an appropriate location for SIP is an important step for the successful implementation of the system. The location of the pump, solar array, and controller needs to be carefully evaluated and the potential for generating desired energy from the system needs to be estimated. This process contains several considerations including interconnection, the configuration of the inverter, siting of transformer equipment, zoning, and environmental regulation to determine the viability of the site. 78 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;adl;{jn kDk gfdn] atfP em}+ of] kDk kfgLdf 8'a]sf] x'G5 . o;n] lj:yflkt u/]/ kfgL kDk u5{ / k|foh;f] ulx/f] Ogf/df k|of]u ul/G5 . o;k|sf/sf kDkx? xfO x]8 / dWod axfjsf nflu l8hfOg ul/Psf x'G5g\ . ltgLx? ax'3r/0f cfwfl/t kDk x'g / pRr Ifdtf af]s]sf] dfOqmf] sDKo'6/df cfwfl/t OGe6{/n] rN5 . OGe6{/n] nufOPsf] kfj/nfO{ clwsQd pkof]u u5{ / o;k|sf/ ;du| Kofgnsf] sfo{Ifdtf a9fpF5 . ;km]{; kDkeGbf oL kDkx?sf] d"No dxFuf] x'G5 t/ lbuf]] x'G5 / ;km]{; kDkeGbf w]/ } e/kbf]{ x'G5 . tl:j/ @$ kfgLdf 8'Ag] gd"gf kDk -k]8«f]nf], @)@!_ tflnsf ! ;km]{; / ;adl;{jn kDksf] t'ngf ;km]{; kDkx? ;adl;{jn kDk " k|fOldª ug{ cfjZos 5 . " k|fOldª ug{ cfjZos x'Gg . " ;txdfly /xg] x'gfn] rf]/Lx'g] hf]lvd /xG5 " rf]/Lsf] ;Defjgf sd x'G5 . " jftfj/0fLo k|efjn] 6'6km'6 x'g] ;Defjgf " jftfj/0fLo k|efjn] 6'6km'6 x'g] ;Defjgf x'G5 . sd x'G5 . " dd{t ;Def/sf nflu ;xh kx'Fr x'G5 . " Psk6s h8fg u/]kl5 x6fpg c;xh x'G5 . " :yfgLo ahf/df kf6{k"hf{x? ;xh pknAw " ;du|df dd{tsf] vfFrf] x'G5 / k|To]s kfFr x'G5 -g]kfnsf] ;Gbe{df_, / pQm sf/0fn] jif{df SjfOnsf] l/jfOlG8ª -a]g]{_ ug'{k5{{ . kDksf] cfo" nDAofpg ;lsG5 . " ;adlh{an kDk lbuf]] x'G5 lsgeg] lolgx? :6}gn]; l:6naf6 lgld{t x'G5 . ;f}o{ kDk h8fgsf] ;fdfGo kl/b[Zo ;fO6 5gf}6 ;f}o{ kDksf nflu pko'Qm :yn rog ug'{ l;:6dsf] ;kmn sfof{Gjogsf] dxTjk"0f{ sbd xf] . kDk h8fg ug]{ :yn, ;f}o{ Kofgn, / sG6«f]n/nfO{ Wofgk"j{s d"Nofª\sg ug'{k5{ / Kofgnaf6 cfkm"n] ck]Iff u/]sf] pmhf{ pTkfbgsf] ;DefjgfnfO{ cg'dfg ug'{ cfjZos x'G5 . o;k|s[ofdf pkoQ' m :ynsf] lgwf{/0fsf nflu OGe6{/sf] ;+/rgf, 6«fG;kmd{/ pks/0fsf] :yn rog, e" ;|f]t ;Ldfª\sg / jftfj/0fLo lgodg;lxt cg]sf}+ s'/fsf] Wofg /fVg'k5{ . 79 Training manual on Solar Irrigation Pumps | If a PV panel’s orientation or tilt varies significantly from optimal for a given location, the potential energy yield reduces accordingly. Thus, the practicality of array tilt and orientation must be evaluated while on site which is important for the system design later. The optimal combination of panel tilt and direction will depend on a few factors such as geographical location, seasonal weather, and system application. With the designed components, such as the annual insolation tool, you can create a chart for quickly evaluating potential energy production as it changes with the panel positions. The results will reveal the ideal panel orientation and tilt for an unshaded panel in a particular location. Normally, the process of a site evaluation is completed in the following steps: 1. First, the proper site for the solar power plant is to be located based on considerations of the location of water use, land availability and permits, suitability of land (minimum shading, minimum site grading required, etc.). 2. Then, the solar insolation data for a given location is obtained. This can be done by using online databases and software such as SolarGIS, PVSyst, etc. The atmospheric data provided by the software considers various eects such as atmosphere temperature, humidity, solar radiation, wind speed, direction, etc. on monthly basis. 3. Then, the most preferable site is to be selected by comparing the necessary atmospheric data. SIP Installation Solar panels and structure " Make sure the installation area is clear and ready for installation. The support structure must be erected on a clear, dry, and level area. " Make sure the panels are facing south and do not have any near or far shadings. For an optimum generation, the modules must be placed at an angle of 30o (in Nepal’s context). " For concrete footing, wait for the mixture to dry before installing the solar panels. The ground clearance of the modules must be at least 0.3m (1ft) to avoid high shading from ground vegetation. " Spacing between adjacent modules must be at least 5mm to 10mm between the rows/column. " All the modules must be mounted with the help of a nut, bolts, and spring washer. " Ensure that the structure is rigid and there are no sags in the structure which may indicate mechanical stress. " A suitable size of string breaker must be used in between modules and controller. Pumps " All the plumbing work connected to the pumps needs to be leak-proof. " The surface pump needs to be placed under protective housing to protect it from the environment. The pump housing must allow proper ventilation and enough room for plumbing work. " The submersible pump needs to be properly fastened with a stay wire to hold the pump under the water. To allow ease of repair and maintenance, a union should be placed above the pump. " All electrical connections must be properly insulated. 80 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf olb s'g} lkeL Kofgnsf] cleljGof; -orienta}on_ jf em'sfj s'g} lbOPsf] :yfgsf nflu k|lts'n ?keGbf leGg x'G5 eg] ;Defljt pmhf{ pTkfbg ;f]xL adf]lhd sd x'G5 . t;y{, P/] l6N6 / cled'vLs/0f -orienta}on_ sf] Jofjxfl/stf ;fO6df x'Fbf d"NofÍg ul/g' k5{ h'g kl5 k|0ffnL l8hfOgsf] nflu dxQ\jk"0f{ 5 . ;Defljt pmhf{ pTkfbgsf] b|'t d"Nofª\sgsf nflu Pp6f dfglrq agfpg ;lsG5 lsgeg] Kofgnsf] l:ylt;Fu} of] kl/jt{g eO/xG5 . glthfx?n] Kofgnsf] k|lts'n orienta}on / l6N6sf] hfgsf/L lbG5 . ;fdfGotof, ;fO6 d"Nofª\sgsf] k|s[of lgDg adf]lhd k'/f ug{ ;lsG5 M != klxnf], kfgL k|of]usf] :yfg, hUufsf] pknAwtf / cg'dlt, hUufsf] pko'Qmtf -Go'gQd 5fofF x'g], :yfgsf] Go'gQd >[+vnfs/0f cfjZos, OToflb ._ @= lbOPsf] :yfgdf ;"o{sf] ls/0f k'Ug] tYofª\s k|fKt x'G5 . / of] k|s[of cgnfOg 8f6fa]; / ;km\6j]o/ h:t} ;f]nf/ hLcfO{P;, lkeLl;:6 cflb af6 k'/f ug{ ;lsG5 . ;km\6j]o/n] pknAw u/fpg] tYofª\sdf jftfj/0fsf] tfkqmd, cfb|{tf, ;f}o{ ljls/0f, xfjfsf] ult, lbzf OToflbsf] k|efj ;d]tnfO{ dfl;s ?kdf Wofgdf /flvG5 . #= clg, cfjZos jfo'd08nLo tYofª\s t'ngf u/]/ ;a}eGbf /fd|f] :yn rog ug'{k5{ . ;f}o{ kDk h8fg ;f}o{ Kofgn / :6«Sr/ " h8fg ul/g] If]q :ki6 / :yfkgfsf nflu tof/ /x]sf] ;'lglZrt ug'{xf];\ . ;kf]6{ :6«Sr/ ;'Vvf / ;dy/ If]qdf plePsf] x'g'k5{ . " Kofgnx? blIf0ftkm{ kmls{Psf] / glhs jf 6f9f;Dd 5fofF gkg{]]] ;'lglZrt ug{'xf];\ . Oi6td ;f}o{ pmhf{ pTkfbg nflu Kofgnx? #) l8u|Lsf] sf]0fdf 9Ng] u/L /flvg'k5{ -g]kfnsf] ;Gbe{df_ . " ;txdf slGqm6 /flv;s]kl5 ;f}o{ Kofgn h8fg x'g'k"j{ ld>0fnfO{ /fd|/L / kof{Kt ;'Sg lbg'k5{ . hdLgdf pld|g] jg:kltsf] 5fofFaf6 hf]ufpg Kofgnsf] pmrfO{ hdLgaf6 slDtdf )=# ld6/ -Ps lkm6_ x'g'k5{ . " cf;Gg Kofgnx?sf] aLrdf slDtdf kfFr ldlnld6/b]lv bz ldlnld6/sf] cGt/ x'g'k5{ . " ;a} Kofgnx? g6, af]N6 / nlrnf] jfz/sf] ;xof]un] hf]l8Psf] x'g'k5{ . " ;+/rgf l:y/ 5 / ;+/rgfdf oflGqs tgfjnfO{ ;+s]t ug{ ;Sg] ;+/rgfdf s'g} klg :ofux¿ x'g'x'Fb}g h;n] d]sflgsn tgfjnfO{ ;+s]t ug{ ;S5 . " Kofgn / sG6«f]n/sf] aLrdf pko'Qm cfsf/sf] &l:6«ª\u a|]s/Ú /fVg'k5{ . kDk " kDkx?df h8fg ul/Psf ;a} KnlDaª sfo{x? r'xfj63/f]ws x'g' cfjZos 5 . " ;km]{; kDknfO{ jftfj/0faf6 hf]ufpg ;'/IffTds cfjf; d'lg /fVg' cfjZos 5 . kDk xfpl;ªdf plrt e]lG6n]zg / KnlDaª sfdsf] nflu kof{Kt 7fpF x'g'k5{ . " kfgL d'lgsf] kDknfO{ c8\ofpgsf] nflu :6] tf/n] /fd|f];Fu afFWg''k5{ . dd{t ;Def/df ;xhtfsf nflu kDkdfly o'lgog /fVg'k5{ . " ;a} lah'nLsf h8fgx¿÷sg]S;gx? /fd|/L OG;'n]6 x'g'k5{ . 81 Training manual on Solar Irrigation Pumps | Figure 25 Installation of Surface Pump in pump housing (left) and Submersible Pump fastened with stay wire (right) Pump Controller " The pump controller must be properly housed inside a box to protect it from rain and dirt with proper labelling (unless the controller is IP68 rated). Figure 26 Pump controller housing Cables " All exposed cables must have an appropriate conduit and be buried at an appropriate depth. " If possible, a UV cable of a suitable cross-section must be used for outdoor purposes. " Cables behind the solar panels need to be neatly fastened using cable ties 82 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf :6] jfo/ PGs/ Anfs PS;]; 8f]/ kDk xfplhªu e]lG6n]zg ljG8f] tl:j/ @% kDk xfplhª\u -b]a|]_ df ;km]{; kDksf] h8fg / kfgLd'lgsf] kDknfO{ :6] tf/n] afFlwPsf] -bfofF_ kDk sG6«f]n/ " kDk sG6«f]n/nfO{ plrt ;+s]tsf] ;fy jiff{ / kmf]xf]/af6 hf]ufpg afs;leq ;'/lIft /flvPsf] x'g'k5{ -sG6«f]n/ IP68 dfkg ul/bf;Dd_ lkeL l8:sg]S6 sG6«f]n/ aS; sG6«f]n/ Pdl;aL e]G6Ln];g ;h{ k|f]6]S6/ 8LPn /}n OSjkf]6]lG;on u|fp08Lª 6ld{gn cuf8Laf6 x]bf{ s]jn UNof08;\ ;fO8af6 x]bf{ -9f]sf vf]n]sf]_ tl:j/ @^ kDk sG6«f]n/ xfplhª\u tf/x? " ;a} v'nf tf/x? /fd|/L afFlwPsf] / pko'Qm kfOk leq x'g'k5{ / pko'Qm ulx/fOdf ufl8Psf] x'g'k5{ . " ;Dej eP, aflx/L p2]Zosf nflu pko'Qm qm;;]Szgsf] o"eL tf/ k|of]u ug'{k5{ . " ;f}o{ Kofgn k5fl8sf] tf/x?nfO{ /fd|/L afFWg h?/L x'G5 . 83 Training manual on Solar Irrigation Pumps | Float Switch " A float switch is a contact switch that signals the controller whether the water level in the source is adequate or not, and stops the pump from running dry when the water level is low. " It protects the pump from dry run and damages due to overheating. Grounding Pits " Grounding must be given to the pump, controller, panel, panel structure, and controller body. " The ground pit should be near the solar panel structure and where soil resistivity is low. " Measure ground resistance after the ground electrodes have been installed and make sure they meet the required value. Usually, the grounding resistance should be 10 ohms or less. 84 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Ænf]6 :jLr " Ænf]6 :jLr eg]sf] h;n] sG6«f]n/nfO{ ;|f]tdf kfgLsf] :t/ kof{Kt 5 jf 5}g egL ;+s]t u5{ / kfgLsf] :t/ sd xF'bf kDknfO{ ;'Vvf rNgaf6 /f]S5 . " o;n] kDknfO{ 8«fO{ /gaf6 hf]ufpg'sf ;fy} cf]e/lx]l6+usf] sf/0fn] x'g] Ifltaf6 hf]ufpF5 . cly{ª÷u|fplG8ª\u lk6 " kDk, sG6«f]n/, Kofgn, Kofgnsf] :6«Sr/ / sG6«f]n/ a8LnfO{ u|fplG8ª\u lbOg'k5{ . " hldgsf] vfN8f] ;f}o{ Kofgn ;+/rgfsf] glhs / df6f]sf] k|lt/f]wstf sd ePsf] 7fpFdf x'g'k5{ . " u|fpG8 On]S6«f]8x? ufl8;s]kl5 hldgsf] k|lt/f]w dfkg ug'{xf];\ / lolgx?sf] cfjZos dfkg k'/f u/]sf] ;'lglZrt ug'{xf];\ . k|fo h;f], u|fplG8ª k|lt/f]w !) cf]xd jf ;f]eGbf sd x'g'k5{ . 85 Training manual on Solar Irrigation Pumps | 6. Annex: Installation Report Template Date of installation Date of commissioning Contact person Phone System location Pumping head Water source Water output per day Application 100% powered by solar (Yes/No) Pump Installation data: Best describe the weather condition Array mount spacing Panel mount structure material Angle of tilt Mounting structure type Mounting and PV module frame grounding (Yes/No) Module installation location No. in series No. in parallel String Parameters: Circuit breaker rating Voltage V oc Voltage V mp Current Grounding connection (Yes/No) Cable insulation (Yes/No) Cable labelling (Yes/No) Continuity check (Yes/No) Controller Controller model Protection rating Cable labelling (Yes/No) Serial numbers PV panels serial numbers Module 1 Module 2 Module 3 Module 4 Module 5 Module 6 Cables  86 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf String cables appropriately conduit/ tied to the frames (Yes/No) Underground piping (Yes/No) Cable length from the controller to pump Wiring size from the controller to pump Lightning Arrestor parameters Lightning Arrestor type Lightning Arrestor position Lightning Arrestor height from the top of the solar array Main copper strip dimension Main copper strip length Earthing wire length to earthing pit The material used at grounding Earthing wire size Pump Power rating Pump manufacturer Pump model/serial number Pump type Outlet diameter Inlet diameter Wire contact check Pump body earthing System Performance Table Observation date: Describe weather condition (cloudy/clear): Tests are done by bucket test. The time taken to fill a bucket is recorded with three sample readings. Bucket volume: ……………… Liters 87 Training manual on Solar Irrigation Pumps | Time taken to fill the S.N Time of reading Water Discharge LPM bucket (Sec) 1 2 3 Guideline for the Photographs of Installation 1. Area of PV array and structure before and after installation 2. Cables and conduits below the panels 3. Controller box 4. UV cable routing pathway 5. Pump installation 6. Water discharge from the Pump 88 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ^= cg';"rLM h8fg l/kf]6{sf] gd"gf h8fg÷:yfkgf ePsf] ldlt rfn" ePsf] ldlt ;Dks{ JolQm kmf]g l;:6d :yfg klDkË x]8 kfgLsf] d'xfg÷;|f]t kfgL pTkfbg k|tL lbg pkof]u ;f}o{af6 zt k|ltzt ;~rflnt -xf]÷xf]Og_ kDk :yfkgf 8f6fM df};dsf] cj:yfnfO{ /fd|/L j0f{g ug]{ P/] larsf] b'/L P/] :6«Sr/sf] ljj/0f Kofgnsf] 9NsfO{ (Angle) P/] :6«Sr/sf] k|sf/ dfplG6ª / lkeL Kofgn km|]d u|fplG8ª -cly{ª_ -5÷5}g_ P/] h8fg -:yfkgf_ :yfg l;l/h ;+Vof Kof/]nn ;+Vof :6«LË kf/fld6/M ;ls{6 a|]s/ /]l6+u ef]N6]h -Voc_ ef]N6]h -Vmp_ s/]G6 (A) u|fpG8LË sg]S;g -cly{ª_ -5÷5}g_ s]jn OG;'n]zg -5÷5}g_ s]jn n]alnª\u -5÷5}g_ sG6LGo"6L r]s -5÷5}g_ sG6«f]n/ sG6«f]n/sf] df]8n ;'/Iff /]l6+ux? s]an n]aln+u -5÷5}g_ l;l/on gDa/ lkeL Kofgnsf] l;l/on gDa/x? 89 Training manual on Solar Irrigation Pumps | Kofgn ! Kofgn @ Kofgn # Kofgn $ Kofgn % Kofgn ^ tf/x? tf/nfO{ km|]ddf pko'Qm kfOk leq nu]sf] jf k|m]ddf afFw]sf] x'g'k¥of] hldgd'lg kfOk h8fg -l7s÷a]l7s_ sG6«f]n/b]lv kDk;Ddsf] tf/sf] nDafO sG6«f]n/b]lv kDk;Dd tf/sf] ;fOh nfO6lgª\u P/]:6/ kf/fld6;{ nfO6lgª\u P/]:6/ k|sf/ nfO6lgª\u P/]:6/ kf]lhzg ;f}o{ P/]sf] 6'Kkf]af6 nfO6lgª\u P/]:6/sf] prfO{ tfdfsf] d'Vo l:6«ksf] gfk tfdfsf] d'Vo l:6«ksf] nDafO{ cly{ª\u lk6b]lv cly{ª\u tf/sf] nDafO{ u|fplG8ª\u ubf{ pkof]u ul/Psf] j:t' -s]ldsn 5÷5}g_ cly{ª\u tf/ nDafO{ kDk kfj/ /]l6Ë kDk pTkfbs kDksf] gd"gf÷l;l/on gDa/ kDk k|sf/ cfp6n]6 8fold6/ Ogn]6 8fold6/ tf/ k/LIf0f kDk cly{ª k|0ffnL sfo{ tflnsf cjnf]sg ldlt df};dsf] cj:yf j0f{g -afbn nfu]sf]÷5n{ª\u 3fd_ k/LIf0fx? afN6L hfFraf6 k'/f ul/G5 . Pp6f afN6L eg{ nfUg] ;do tLg j6f gd"gf l/l8+U;sf ;fy /]s8{ ug'{xf];\ . afN6Lsf] cfotg M =====ln6/ 90 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf qmd ;+= l/l8ª\usf] ;do jf6/ l8:rfh{ afN6L eg{ nfu]sf] ;do -;]s]08_ nL6/ k|lt ldg]6 ! @ # h8fgsf] tl:j/x?sf] nflu lbzflgb]{z != :yfkgf ug'{ cl3 / kl5 lkeL P/]sf] If]qkmn / agfj6 @= Kofgnd'lg tf/ / gnL #= sG6«f]n/ afs; $= o"eL tf/ hfg] af6f] %= kDk h8fg ^= kDkaf6 kfgL l8:rfh{ 91 Training manual on Solar Irrigation Pumps | Section III: Operation and Maintenance of SIPs 92 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf v08 # M ;f}o{ kDksf] ;~rfng / dd{t 93 Training manual on Solar Irrigation Pumps | 7. Routine Maintenance and Preventive Maintenance Regular maintenance ensures that the PV system works without problems for many years. Usually, solar pumps require only simple maintenance that can be easily done. Dirty panels reduce eciency PV Array of the system due to soiling losses Figure 27 PV Array Maintenance (ecoPlanetenergy, 2016) " Check the PV array and mounting structure nut and bolts for adequate tightening. If found to be loose, repair it accordingly. " Ensure that the solar PV modules do not have any cracks or hot spots. Otherwise, disconnect the solar panel(s) and replace it. " All cables need to be properly insulated, terminated, and properly routed with or without conduits. " Make sure the earthing connections are properly connected. 94 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf &= lgoldt dd{t;Def/ / lg/f]ws dd{t;Def/ lgoldt dd{t;Def/n] lkeL k|0ffnL w]/} jif{sf] nflu ;d:of lagf sfd u5{ eg] ;'lglZrt u5{ . ;fdfGotof, ;f}o{ kDkx?nfO{ ;/n dd{t ;Def/sf] cfjZostf k5{ h'g ;lhn} ug{ ;lsG5 . Kofgn kmf]xf]/ eP df6f]n] x'g] n;n] P/]sf] kfj/ sd u5{ . lkeL P/] tl:j/ @& lkeL P/] dd{t -Osf] Knfg]6]glh{, @)!^_ " lkeL P/] / dfplG6ª\u :6«sr/sf] g6 af]N6x? kof{Kt dfqfdf s;]sf] 5 egL k/LIf0f ug'{xf];\, obL v's'nf] 5 eg] o;nfO{ ;f]xL adf]lhd dd{t ug'{xf];\ . " ;f}o{ lkeL Kofgnx?df s'g} b/f/ jf x6 :k6x? 5}gg\ eGg] ;'lglZrt x'g'xf];\ . olb 5 eg] ;f}o{ KofgnnfO{ h8fgaf6 cnUofP/ gofF Kofgn h8fg ug'{xf];\ . " ;a} tf/x? /fd|/L OG;'n]6 ul/Psf], aGb ul/Psf] / l7s tl/sfn] ?6 ul/g' cfjZos x'G5 . " cly{ª /fd|/L h8fg ePsf 5g\ egL ;'lglZrt ug'{xf];\ . 95 Training manual on Solar Irrigation Pumps | Pump Figure 28 Submersible pump (Pedrollo, n.d.) " Check if the system is performing as per the specification of the supplier (looking at parameters like the discharge of water at specified total dynamic head, ambient temperature, and input power). " Make sure the earthing connections are properly connected. Controller box Figure 29 Controller (Made-in-China, n.d.) " The junction box should be firmly attached. If it is not, attach it correctly with screws. " The controller box must be clean and dry on the inside. " All cable connections need to be properly screwed with no loose terminals. " Look for burnt wires, bits of black debris, and any other signs of lightning damage. " Inspect the grounding wires and connections. Most controller failures are caused by an induced surge from nearby lightning where the system is not eectively grounded. Ground connections must be properly made and free of corrosion. 96 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf kDk tl:j/ @* kfgLdf 8'Ag] kDk -k]8«f]nf], Pg=8L=_ " l;:6dn] cfk"lt{stf{n] lglb{i6 u/] adf]lhd rln/x]sf] 5 5}g\ eGg] k/LIf0f ug'{xf];\ -h:t} sL, lglb{i6 s'n 8fOgflds x]8, kl/j]z tfkdfg / Ogk'6 kfj/ cg';f/ kfgLsf] l8:rfh{ h:tf dfkgx? x]g]{ ._ " cly{ª h8fgx? 7Ls;Fu hf]l8Psf] ;'lglZrt x'g'xf];\ . sG6«f]n/ aS; tl:j/ @( sG6«f]n/ -rLgdf lgld{t, Pg=8L=_ " h+Szg aS; sl;g] u/L hf]l8Psf] x'g'k5{ . olb 5}g\ eg] o;nfO{ :qm"n] ;xL ?kdf hf]8\g'xf];\ . " sG6«f]n/ aS; leqk§L ;kmf / ;'Vvf x'g'k5{ . " ;a} tf/ hf]l8Psf] 7fpF :qm"n] ;xL ?kdf hf]l8Psf] x'g'k5{, 6ld{gndf v's'nf] h8fg ePsf] x'g'x'Gg . " 89]sf] tf/, sfnf] eUgfjz]ifsf] 6'qmf, / lah'nLaf6 ePsf] cGo Ifltsf] ;+s]tx? x]g'{xf]; . " u|fplG8ª\u tf/ / h8fgx? lg/LIf0f ug'{xf];\ . clwsf+z sG6«f]n/ ljkmntfx? glhs}sf] r6\ofª nfUg'af6 x'G5 hxfF k|0ffnL k|efjsf/L ?kdf u|fpG8 ul/Psf] 5}g\ . u|fpG8÷cly{ªsf] sg]S;gx? pko'Qm / lvofd'Qm x'g'k5{ . 97 Training manual on Solar Irrigation Pumps | Besides, several simple faults can arise which need immediate corrections: " Dirty/wet/corroded terminal and/or plugs causing poor electrical connection " Blocked strainers and filters on the pump due to debris " Failure of the suction pump due to leakage of water in the suction line caused by faulty non-return valve or air leaks in suction line (in case of the surface pump) " Leaking pipe and hose connections " Leaking pump gland seal Manufacturers may have special recommendations for routine maintenance which need to be strictly followed for the long-term operation of the system. Logs of any scheduled or unscheduled maintenance works must be recorded by the technicians which must be maintained on-site and in the remote oce. Cables Figure 30 SIP showing major cable arrangements (Made-in-China, n.d.) " All cables in the system need to be properly insulated, terminated, and properly routed with or without conduits. " The cable from the controller to the pump needs to be water-sealed. " Check that the cable from the controller to the is well fastened and does not rub against sharp edges when the wind blows. In the case of underground cabling, ensure that the conduit or the cable is not exposed to the ground. " If any cables have been replaced since the last check, make sure that it is of the correct specifications (size, material, insulation, etc.) and that it is well terminated and fastened securely in their new place. " Check the connections for corrosion and tightness. 98 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf o;afx]s, cg]sf}+ ;fwf/0f q'6Lx? cfpg ;S5g\ h;nfO{ lz3| ;'wf/ ug{ cfjZos x'G5 . " kmf]xf]/÷leh]sf]÷lvof nfu]sf] 6ld{gn jf sdhf]/ ljB'tLo h8fg ePsf] Knux? . " lxnf]÷9'Fufsf sf/0f kDkdf lkmN6/x? cj?4 . " q'6Lk"0f{ gg3l/6g{ eNe jf ;Szg nfOgdf xfjf l5g]{ l5b|sf] sf/0fn] ubf{ ;Szg nfOgdf kfgLsf] r'xfj6 x'g'n] ;Szg kDksf] ljkmntf -;tx kDksf] cj:yfdf_ . " r'lxg] kfOk / h8fgx? . " UNof08 l;naf6 kfgL r'lxg' . kDk lgdf{tfx?;Fu lgoldt÷cfjlws dd{/tsf nflu ljz]if l;kmfl/zx? x'g ;S5g\ h'g k|0ffnLsf] bL3{sfnLg ;~rfngsf nflu s8fOsf ;fy kfngf ug{ cfjZos x'G5 . s'g} klg lgwf{l/t jf clgwf{l/t dd{t sfo{ k|fljlwsx?n] /]s8{ ug{'k5{ h'g dd{t :yn / sfof{nodf /fVg'k5{ . tf/x? ;f}o{ Kofgn P/] ;f}o{ sG6«f]n/ jf6/ 6ofª\s jf6/ ;]G;/ Kofgn l6N6 P+un l8;L Po/ l8;L s]a'n :jLr df]6/ s]a'n ;]G;/ s]a'n jf6/ ;]G;/ kfOk nfOG; jf6/ kDk tl:j/ #) ;f}o{ kDksf] d'Vo tf/ Joj:yfkg b]vfO+b} -rLgdf lgld{t, Pg=8L=_ " k|0ffnLdf ePsf ;a} s]anx? /fd|f];Fu OG;'n]6 ul/Psf] / /fd|f]l;t kfOkdf jf s]a'n 6fO{n] afFl9Psf] x'g'k5{ . " sG6«f]n/af6 kDk;Dd uPsf] tf/nfO{ kfgLsf] ;Dks{df gcfpg] u/L ;Ln ug'{k5{ . " sG6«f]n/ / s]a'n /fd|f];Fu afFlwPsf] 5 / xfjf rNbf wfl/nf] lsgf/fx?df /ul8Psf] 5}g egL hfFr ug'{xf];\ . e"ldut s]alnªsf] cj:yfdf s]a'n hldgdf v'nf g/x]sf] ;'lglZrt x'g'xf];\ . " kl5Nnf] k6s k/LIf0f u/] otf s'g} s]a'n lj:yflkt ul/Psf] 5 eg] of] ;xL lglb{li6s/0fx? -cfsf/, ;fdu|L, OG;'n]zg, cflb_ sf] xf] / /fd|/L k'/f ePsf] 5 / gofF :yfgdf ;'/lIft ?kdf afFlwPsf] 5 eg]/ ;'lglZrt ug'{xf];\ . " ;a} h8fgx?df lvof gnfu]sf] / /fd|/L sl:;Psf] 5 eg]/ k/LIf0f ug'{xf];\ . 99 Training manual on Solar Irrigation Pumps | " Ensure that the path of cable routing (underground or exposed) is dry. Water puddles on the path of cables increase the risk of short-circuiting. Protection and other components " Check whether the lightning air terminal and its grounding path are properly fastened and the lightning air terminal pole is straight and not touching any other metallic surface. 100 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf " s]a'nsf] ky -e"ldut jf v'nf_ ;'Vvf /x]sf] ;'lglZrt x'g'xf];\ . s]a'nsf] kydf kfgLsf] vf8nn] z6{3;ls{6sf] hf]lvd a9fpF5 . ;+/If0f / cGo sDkf]g]G6x? " r6\ofª /f]Sg -nfO6lgª_ Po/ 6ld{gn / o;sf] u|fplG8ª dfu{ 7Ls;Fu hf]l8Psf] 5 ls 5}g / nfO6lgª Po/ 6ld{gn kf]n ;Lwf 5 / s'g} cGo kmnfd;Fu 5f]Psf] 5}g eg]/ hfFr ug{'xf];\ . 101 Training manual on Solar Irrigation Pumps | 8. Failure and Troubleshooting Failures are inevitable in most systems, even in well-maintained and designed systems. There could be two types of such failure: Type 1: Whole system and all its appliances are not working Type 2: The system works but water output is low/intermittent Type 1 Problems in the fuses and miniature circuit-breakers " The first step for any troubleshoot or repairing is to disconnect the PV array. Check whether fuses or miniature circuit breakers in the system for damages (for example, loose connections and burnt smell/spots). " Corrective action o Disconnect all the loads from the controller. o If the fuse is blown, replace it with the appropriate specifications of the fuse (such as correct current rating). o If the miniature circuit breaker is tripped, check for any cable damages or possible overload that may have caused the surge current to trip the breaker. Correct any problems in the system. o If the fuse or circuit-breaker does not trip, reconnect the load and turn the appliances on. 102 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf *= ;d:of / ;d:ofsf] lgjf/0f clwsf+z k|0ffnLdf c;kmntf lglDtPsf] x'G5 . /fd|/L ;Def/ / l8hfOg ul/Psf] k|0ffnLdf ;d]t o:tf] x'G5 . To:tf ;d:of b'O{ k|sf/sf x'G5g\ . k|sf/ !M ;Dk"0f{ k|0ffnL / o;sf c? pks/0fx?n] sfd ul//x]sf 5}gg\ . k|sf/ @M k|0ffnLn] sfd ul//x]sf] 5 t/ kfgL alxu{dg sd 5 jf cl:y/ 5 . k|sf/ ! km\o'h / Pd;LaL -ldlgPr/ ;ls{6 a|]s/_ df ;d:of " s'g} klg ;d:ofsf] lgjf/0f / dd{tsf] r/0f eGbf cufl8 lkeL P/]nfO{ ljR5]bg ug'{k5{ . km\o'hx? jf Pd;LaLdf s'g} Iflt k'u]sf] 5 ls k/LIf0f ug'{xf];\ -pbfx/0fsf nflu, v's'nf] h8fg / 89]sf] uGw÷bfu_ . " ;'wf/sf] pkfo o sG6«f]n/af6 ;a} nf]8nfO{ cnu ug'{xf];\ . o olb kmo\ h' hns] f ] 5 eg ] o;nfO { pkoQ' m lglbl{ i6s/0f ePsf ] kmo\ h' n ] lj:yflkt ugx{' f;] \ -h:t } ls ;xL s/G] 6 /l] 6Ë ePsf_] . o olb ldlgPr/ ;ls{6 a|]s/ l6«k eof] eg], s'g} klg s]an Iflt jf ;Defljt cf]e/nf]8sf] nflu hfFr ug{'xf];\ h;n] a|]s/nfO{ l6«k u/]sf] x'g ;S5 . k|0ffnLdf s'g} klg ;d:of cfPsf] eP 7Ls ug'{xf];\ . o obL km\o'h jf ;ls{63a|]s/ l6«k ePsf] 5}g\ eg] nf]8nfO{ k'gM h8fg ug'{xf];\ / pks/0fx? rnfpg'xf];\ . 103 Training manual on Solar Irrigation Pumps | Faulty panel or panel wiring Figure 31 Faulty panel or panel wiring " Disconnect the PV array. " Check the array V and correlate with the radiation to ensure that the array V is correct. oc oc " If the solar array voltage is less or more than the configured voltage, there is a problem with the panel or the panel wiring. Check all series and parallel connections. " If the current is low for a panel or array, the connections to the panel or array may be loose or corroded. Possibly, panel(s) may also be damaged. Corrective action: Disconnect all pan- Make sure that Replace panels that Clean all terminals els and check them panels are clean and aren’t working and cables individually shade-free Verify the V of oc the array 104 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Kofgndf v/faL jf s]andf ;d:of lkeL P/] kmN6 rfh{ sG6«f]n/ Pd;LaL ;f}o{ jf6/ kDk tl:j/ #! Kofgndf v/faL jf s]jndf ;d:of " lkeL P/]sf] h8fg x6fpg'xf];\ . " P/]sf] Voc hfFr ug'{xf];\ / P/]sf] Voc ;xL 5 eg]/ ;'lglZrt ug{ ljls/0f;Fu t'ngf ug'{xf];\ . " olb ;f}o{ P/] ef]N6]h sd 5 jf ;+/rgfTds ef]N6]heGbf a9L 5 eg] of t Kofgndf jf Kofgnsf] jfol/ª\udf ;d:of /x]sf] a'em\g'xf];\ . ;a} l;l/h / Kof/nn h8fgsf] k/LIf0f ug'{xf];\ . " olb s'g} Kofgn jf P/]df s/]G6 k|jfx sd 5 eg] Kofgn jf P/];Fusf] h8fg v's'nf] jf hL0f{ ePsf] x'g;S5 . ;DejtM Kofgn -x?_ v/fa ePsf] klg x'g ;S5 . ;'wf/sf sfo{ M ;a} Kofgsf] sg]S;g sfd gu/]sf ;a} 6ld{gn / ;a} Kofgnx? ;kmf x6fP/ k/LIf0f ug'{xf];\ . KofgnnfO{ lj:yflkt s]a'nx?nfO{ ;kmf / 5fofFF /lxt /x]sf] ug'{xf];\ . ug'{xf];\ . ;'lglZrt ug'{xf];\ . P/]sf] eLcf];L hfFr ug'{xf];\ . 105 Training manual on Solar Irrigation Pumps | Faulty controller Figure 32 Faulty controller " First, check for any fault indicators and fault code. Refer to the controller’s manufacturer manual for the description of the fault. " Check the DC voltage (V and V ) at the input side of the controller when the controller is in the o and on oc mp mode. Correlate the input voltage with the radiation to ensure that the DC input voltage is correct. When the controller is on and should be powering the load, check the input and output power using a multimeter (measure voltage and current, then calculate power) or from the controller display. Correlate the input power with the output power to ensure that the controller is working correctly. " Check all input parameters in the controller. For example, correct entry of pump capacity, pump voltage, pump current, array size, etc. Corrective action: Diagnose the fault indi- Ensure all input parame- Replace the controller if it cated by referring to the ters are correct is deemed damaged controller manual 106 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf sG6«f]n/df v/faL lkeL P/] rfh{ sG6«f]n/ kmN6 Pd;LaL ;f}o{ jf6/ kDk tl:j/ #@ sG6«f]n/df v/faL " klxn], s'g} klg q'6L ;"rsx? / q'6L sf]8 /x] jf g/x]sf] hfFr ug'{xf];\ . q'6Lsf] ljj/0fsf] nflu sG6«f]n/sf] lgdf{tf lgb]{lzsf -d}g'cn_ df q'6Lsf] ljj/0f;Fu bfFHg'xf];\ -ldnfpg'xf];\_ . " sG6«f]n/ ckm / cg cj:yfdf x'Fbf sG6«f]n/sf] Ogk'6lt/ l8;L ef]N6]h -Voc / Vmp_ k/LIf0f ug'{xf];\ . l8;L Ogk'6 ef]N6]h ;xL 5 eg]/ ;'lglZrt ug{ ljls/0f;Fu Ogk'6 ef]N6]hnfO{ bfFHg'xf];\ . ha sG6«f]n/ cg 5, nf]8nfO{ kfj/ lbO/x]sf] x'G5, dlN6ld6/ -ef]N6]h / s/]G6 gfKg'xf];\ / To;kl5 kfj/sf] lx;fa lgsfNg'xf];\_ jf sG6«f]n/ l8:Kn]sf] pkof]u u/]/ Ogk'6 / cfp6k'6 kfj/ hfFr ug'{xf];\ . sG6«f]n/n] 7Ls;Fu sfd ul//x]sf] 5 ;'lglZrt ug{ Ogk'6 kfj/nfO{ cfp6k'6 kfj/;Fu ldnfpg'xf];\ . " sG6«f]n/df /x]sf] ;a} Ogk'6 kf/fld6/ -dfkg_ sf] k/LIf0f ug'{xf];\ . pbfx/0fsf nflu kDk Ifdtf, kDk ef]N6]h, kDk s/]G6 / P/]sf] cfsf/ cflbsf] OlG6« 7Ls kfg'{xf];\ . ;'wf/sf sfo{ M sG6«f]n/ lgb]{lzsfnfO{ ;a} OGk'6 dfkb08x? olb sG6«f]n/ gi6 ePsf] 5 ;Gbe{ u/]/ ;+s]t ul/Psf] ;xL /x]sf] ;'lglZrt eg] lj:yflkt ug'{xf];\ . q'6Lsf] lgjf/0f ug'{xf];\ . x'g'xf];\ . 107 Training manual on Solar Irrigation Pumps | Faulty pump Figure 33 Faulty pump " First, check if cable connections to the pump are correct, waterproof, and tightened. " Check for any debris in the pump inlet that may have jammed the pump. " If the pump seems to be jammed, dismantle the pump and clear the debris. Check the impeller for any damage. " Disconnect the pump and check if the pump rotor can be rotated freely. " For submersible pumps, check whether the rotor and impeller connecting teeth are well connected and gripped. Corroded teeth can result in rotor slippage. " Correcting action: o For impeller damage, replace the impeller. o If the rotor is jammed without debris, contact the supplier or manufacturer. o If the rotor and impeller connecting teeth are corroded, replace the teeth after contacting the supplier or manufacturer. Corrective action: If the rotor is jammed For impeller damage, If the rotor and impeller con- without debris, contact the replace the impeller necting teeth are corroded, supplier or manufacturer replace the teeth after contacting the supplier or manufacturer 108 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf kDkdf v/faL lkeL P/] rfh{ sG6«f]n/ Pd;LaL kmN6 ;f}o{ jf6/ kDk tl:j/ ## kDkdf v/faL " klxnf], kDk;Fusf] s]a'n /fd|/L h8fg eP jf gePsf], kfgL k|lt/f]ws -jf6/ k|'km_ sfd u/]÷gu/]sf] / sl:;Psf] 5÷5}g\ hfFRg'xf];\ . " kDksf] Ogn]6df s'g} kmf]xf]/ y'lk|Psf] 5÷5}g\ hfFRg'xf];\ h;n] kDk hfd u/]sf] x'g ;S5 . " olb kDk hfd ePsf] 5 eg] kDk x6fP/ kmf]xf]/ vfln ug'{xf];\ . ODk]n/df s'g} ;d:of cfPsf] xf] sL hfFRg'xf];\ . " kDksf] h8fg x6fP/ kDksf] /f]6/ :jtGq?kn] 3'd]sf] 5÷5}g\ hfFRg'xf];\ . " kfgLdf /xg] kDkx?sf] nflu /f]6/ / ODk]n/ hf]8\g] bfFt /fd|f];Fu hf]l8Psf] / a;]sf] 5÷5}g\ hfFRg'xf];\ . lvOPsf] bfFtn] /f]6/ lrlKng ;S5 . " ;'wf/sf sfo{ o ODk]n/ Iflt ePsf] eg] lj:yflkt ug'{xf];\ . o olb lxnf]÷9'+ufaf6 /f]6/ hfd 5 eg] cfk"lt{stf{ jf lgdf{tf;Fu ;Dks{ ug'{xf];\ . o olb /f]6/ / ODk]n/ hf]8\g] bfFt lvOPsf] 5 eg] lgdf{tf jf cfk"ltstf{;Fu ;Dks{ u/]/ lj:yflkt ug'{xf];\ . ;'wf/ sfo{ olb kmf]xf]/ 5}g / /f]6/ olb /f]6/ / ODk]n/ hf]8\g] bfFt ODk]n/ lau|]sf] 5 eg] hfd 5 eg] cfk'lt{stf{ jf lvOPsf] 5 eg] cfk'lt{stf{ jf lj:yflkt ug'{xf];\ . lgdf{tf;Fu ;Dks{ ug'{xf];\ . lgdf{tf;Fu ;Dks{ u/L bfFt lj:yflkt ug'{xf];\ . 109 Training manual on Solar Irrigation Pumps | Faulty cable between controller and pump Figure 34 Faulty cable between controller and pump " Measure the voltage at the pump and controller terminals. " If the voltage is low even during sunny hours, there may be a cable fault. Note that the output voltage (in the case of AC pumps) of the controller will constantly change as the controller regulates the voltage and frequency of the pump depending on the input power. " Clean/replace corroded cable terminals and tighten all connections. " Make sure that the cable connecting the controller and the pump is of the correct size for the rated pump voltage and current. Faulty fuses or circuit-breakers " Check all fuses and circuit-breakers for any physical damage (puncture, burnt smell, burnt spots, etc.). " If they continuously trip, there is a possible short circuit in the cable or components. " Corrective action: o Fix shorted wiring or faulty components, replace fuses and reset circuit-breakers. 110 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf sG6«f]n/ / kDk aLrsf] s]a'ndf v/faL lkeL P/] rfh{ sG6«f]n/ Pd;LaL kmN6 ;f}o{ jf6/ kDk tl:j/ #$ sG6«f]n/ / kDkaLrsf] s]a'ndf v/faL " kDk / sG6«f]n/ 6ld{gnx?sf] ef]N6]h gfKg'xf];\ . " 3dfOnf] lbgdf klg ef]N6]h sd 5 eg] s]a'ndf q'6L ePsf] x'g;S5 . sG6«f]n/sf] cfp6k'6 ef]N6]h -P;L kDksf] xsdf_ lg/Gt/ kl/jt{g x'g]5 Wofg lbg'xf];\ lsgeg] sG6«f]n/n] Ogk'6 kfj/ -kfj/_ sf] cfwf/df kDksf] ef]N6]h / lkm|Sj]G;L -af/Daf/tf_ nfO{ ldnfpg] u5{ . " lvOPsf] jf lvof nfu]sf] s]a'n 6ld{gnx?nfO{ ;kmf÷abNg'xf];\ / ;a} sg]S;gx?nfO{ s:g'xf];\ . " sG6«f]n/ / kDknfO{ hf]8\g] s]a'n kDksf] dfkb08 adf]lhd ef]N6]h / s/]G6sf] nflu pko'Qm cfsf/sf] /x]sf] ;'lglZrt ug'{xf];\ . km\o'hx? jf ;ls{63a|]s/df v/faL " ;a} km\o'hx? / ;ls{6 a|]s/x?df ef}lts Iflt ePsf] 5÷5}g\ hfFRg'xf];\ -kGr/, 89]sf] uGw, 89]sf] efu, cflb ._ " obL of] lg/Gt/ l6«k u/]sf] 5 eg] s]a'n jf cGo sf/sx?df z6{ ;ls{6 ePsf] x'g ;S5 . " ;'wf/sf sfo{ M o z6 { ePsf ] jfol/ªu\ jf q6' Lk0" f { sDkfg] G] 6x?nfO { klxrfg ug,{] kmo\ h' kl/jtg{ ug {] / ;ls6{ as]| /nfO { kg' M l/;6] ug {] . 111 Training manual on Solar Irrigation Pumps | Type 2 The system works but water output is low/intermittent. This is the most common problem with solar PV systems and can be caused by various factors acting alone or in combination. This may be caused by inadequate power generation from the solar array, issues with power regulation by the controller or issues with pump operation. Inadequate power generation from the solar array " The reason for this may be due to shading, damaged panels, long cables with high power losses, dirty or loose connections, the array not facing the right direction, or dirt on the panels (soiling loss). " Corrective action: o Remove the cause of shading o Align the array in the correct direction and tilt. o Replace any faulty panels. o Check the voltage drop and power losses in the DC cables. If these are higher than the limit (<3% DC voltage loss), either cable size needs to be increased or the length must be decreased. Align the array in the Check for voltage Remove the cause of Replace any faulty correct direction and drop* and power loss shading panels tilt in DC cable. *In case the voltage drop is greater than 3% either increase the cable size or decrease the length. Issues with power regulation by the controller " The pump and array parameters in the controller may be incorrect. " Check the input and output voltage and current at the terminals of the controller. If the array side voltages and currents are not as desired in correlation with the instantaneous radiation, the cables may not have been designed properly (for example, high voltage loss that results in the input voltage being outside of the input voltage range of the controller). If the array side voltages and currents are not as desired, then either the controller circuitry or output cables may be faulty. " The cable connections may be loose or corroded. " Corrective action: o Verify all input (array side) and output (pump side) parameters in the controller with the components used by referring to the manufacturer manual. o Clean or replace all cable connections for proper contacts. o Use a boost controller if the input voltage is too low and is not within the input voltage range of the controller. o If the controller is found to be faulty, replace the controller and send the old one for repair. 112 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf k|sf/ @ k|0ffnLn] sfd u/]sf] 5 t/ jf6/ cfp6k'6 sd 5 jf sdhf]/ 5 . of] ;f}o{ lkeL k|0ffnLsf] ;a}eGbf a9L cfO/xg] ;d:of xf] / of] PSn} sfd ubf{ jf ;+of]hgdf sfd ubf{ ljleGg sf/0fn] x'g ;S5 . of] ;f}o{ P/]af6 ckof{Kt lah'nL pTkfbg, sG6«f]n/af6 pmhf{ ;~rfng jf kDk ;~rfngdf ;d:ofsf] sf/0fn] x'g ;S5 . ;f}o{ P/]af6 ckof{Kt pmhf{ pTkfbg " 5fofFF, lau|]sf] Kofgn, nfdf] s]a'nn] pRr kfj/ n;, kmf]xf]/ jf v's'nf] h8fg -sg]Szg_, P/] pko'Qm lbzfdf gkms]{/ jf Kofgndf kmf]xf]/ a:gfn] -df6f] hd]/ x'g] n;_ o;f] x'g ;S5 . " ;'wf/sf sfo{ M o 5fofFF x'g] sf/0f x6fpg'xf];\ . o P/]nfO{ ;xL lbzf / l6N6df k+lQma4 ug{'xf];\ . o s'g} Kofgndf q'6L 5 eg] kl/jt{g ug'{xf];\ . o l8;L s]a'ndf ef]N6]h 8«k / kfj/ n; gfKg'xf];\ . olb of] ;LdfeGbf pRr -< # k|ltzt l8;L ef]N6]h n;_ 5 eg] of t s]a'nsf] cfsf/ a9fpg'k5{ jf nDafO{ 36fpg'xf];\ . P/]nfO{ ;xL lbzfdf l8;L s]a'ndf ef]N6]h 5fofF x'g] sf/s s'g} Kofgndf q'6L 5 k+lQma4 u/]/ 8«k / pmhf{ n; x6fpg'xf];\ . eg] kl/jt{g ug'{xf];\ . em'sfpg'xf];\ . gfKg'xf];\ . *ef]N6]h 8«k olb tLg k|ltzteGbf a9L 5 eg] s]a'nsf] cfsf/ a9fpg'xf];\ jf nDafO{ 36fpg'xf];\ . sG6«f]n/sf] pmhf{ lgodg;Fu ;DalGwt ;d:ofx? " sG6«f]n/df kDk / P/] dfkb08x? unt x'g ;S5g\ . " sG6«f]n/sf] 6ld{gnx?df Ogk'6 / cfp6k'6 ef]N6]h hfFRg'xf];\ . olb P/] 5]psf ef]N6]h / s/]G6x? tfTsflns ljls/0f;Fu kf/:kl/s 5}gg\ eg] s]a'nx? 7Ls;Fu l8hfOg gul/Psf] x'g ;S5 -pbfx/0fsf nflu pRr ef]N6]h n; h;n] sG6«f]n/sf] Ogk'6 ef]N6]h bfo/feGbf aflx/ x'G5_ . olb P/]sf] ef]N6]hx? / s/]G6x? ck]lIft cg';f/ gePdf of t sG6«f]n/ ;ls{6/L jf cfp6k'6 s]a'nx?df q'6L x'g ;S5 . " s]a'n h8fg v's'nf] jf lvof nfu]sf] x'g ;S5 . " ;'wf/sf] sfo{ o lgdf{tf lgb]{lzsf -dfg'on_ nfO{ pkof]u u/]/ k|of]u ul/Psf sDkf]g]G6x?sf] sG6«f]n/df ;a} Ogk'6 -P/] lt/_ / cfp6k'6 -kDklt/_ sf dfkgx? k|dfl0ft ug'{xf];\ . o plrt ;Dks{x¿sf] nflu ;a} s]a'n h8fgx? ls ;kmf ug'{xf];\ jf x6fpg'xf];\ . o Ogk'6 ef]N6]h cToflws sd 5 eg] sG6«f]n/sf] a':6sf] k|of]u ug'{xf];\ / k'/fgf]nfO{ dd{tsf nflu k7fpg'xf];\ . 113 Training manual on Solar Irrigation Pumps | Issues with pump operation " Long AC cables (usually >100m) result in voltage spikes that may damage the pump insulation over time. Use DU/DT filter when long AC cables are used between the pump and the controller. " The pump may not work correctly if the adequate voltage is not maintained on the pump side due to high voltage losses. Check the voltage drop and ensure correct cable sizing. 114 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf kDk ;~rfng;Fu ;DalGwt ;d:ofx? " nfdf] P;L s]a'nx? -;fdfGotof !)) ld6/eGbf nfdf]_ n] ef]N6]h :kfOs lgDTofpF5 h;n] ;do ;dodf kDksf] OG;'n]zgnfO{ laufg{ ;S5 . kDk / sG6«f]n/sf] aLrdf nfdf] s]a'n k|of]u eP 8Lo"÷8L6L lkmN6/ nufpg'k5{ . " kDklt/ kof{Kt ef]N6]h ;Gt'ng gul/P pRr ef]N6]h n;n] kDknfO{ ;xL?kdf sfd ug{ lb+b}g . ef]N6]h sd ePsf] hfFRg'xf];\ / s]a'nsf] ;fOlhª\u ;xL /x]sf] ;'lglZrt ug{'xf];\ . 115 Training manual on Solar Irrigation Pumps | 9. Electrical Testing Equip yourself with a multimeter, clamp meter, and other required tools before electrical testing. Ensure safety precautions such as the use of insulating gloves while working with power circuits. Check for the following, Array open circuit voltage " Problem: No current is being drawn and is normally high (idle voltage). o Solution: Conduct a short circuit current or spark test, ÷ Disconnect the array from the controller and measure its short circuit current (a short circuit at the array will only cause a current slightly higher than normal). Voltage under load (with running pump) " Problem: If the input connection to the controller is connected in reverse polarity, the controller will not power on. o Solution: No damage will be caused if the controller has reverse polarity protection. Correct the connection polarity. " Test the motor circuit (resistance test with power o), conduct this test if there is a proper voltage at the controller input but the motor does not run. It will confirm the condition of the entire motor circuit, including the motor, pump cable, and splice connections. " Test the running current of the motor circuit (AC amps), this is useful as it indicates the force (torque) that the motor is applying to the pump. " Compare the reading with the nominal specifications provided by manufacturers to better understand if the workload on the motor is normal. " Higher current (especially pump overload light) may indicate: o The pump may be dealing with excessive sediment (such as sand or clay). The total dynamic head (vertical lift plus pipe friction) may be higher than expected. o There may be an obstruction to the water flow- check for sediment/ice in the pipe, a crushed section of the pipe, or a partially closed valve(s). o Helical rotor models: if water is warmer than 72°F (22°C), this could cause the rubber stator to expand and tighten against the rotor (temporarily, non-damaging). o Helical rotor models: Pump may have run dry. Remove the pump stator (outer body) from the motor, to reveal the rotor. If there is some rubber stuck to the rotor, the pump end must be replaced. " To reset the overload shut o (red light), switch the controller o and on again. Lower current may indicate: o The pump head (rotor and impeller connection) may be worn, thus easier to turn than normal (especially if there is abrasive sediment). o The transmission and distribution pipes may have leakages that may be reducing the pressure load. o The pump may not be pumping and may be running dry. 116 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf (= ljB'tLo k/LIf0f ljB'tLo k/LIf0f ug'{cl3 cfkm"nfO{ dlN6ld6/, SNofDk ld6/ / c? cfjZos pks/0f lnP/ ;';lHht x'g'xf];\ . kfj/ ;ls{6 ;DaGwL sfdx? Ul//xFbf h:t} ls OG;'n]l6ª\u Unf]E; nufotsf ;'/Iff ;fjwfgL ckgfPsf] ;'lglZrt ug'{xf];\ . lgDg hfFr ug'{xf];\ . P/]sf] v'nf ;ls{6 ef]N6]h " ;d:of M s'g} klg s/]G6 au]sf] 5}g\ / ;fdfGotof pRr 5 -lgliqmo ef]N6]h_ . o ;dfwfg M ;6{ ;ls{6 s/]G6 jf :kfs{ k/LIf0f ;~rfng ug'{xf];\, ÷ P/]nfO{ sG6«f]n/af6 ljR5]b ug'{xf];\ / o;sf] ;6{ ;ls{6 s/]G6 gfKg'xf];\ -P/]sf] ;6{ ;ls{6n] ;fdfGoeGbf yf]/} a9L dfq s/]G6 Nofpg]5 _ . nf]8 cGtu{t ef]N6]h -kDk ;~rfngdf /xFbf_ " ;d:of M olb sG6«f]n/df Ogk'6 h8fg l/e;{ kf]nfl/6Ldf hf]l8Psf] 5 eg] sG6«f]n/n] kfj/ cg ub}{g\ . o ;dfwfg M olb sG6«f]n/df l/e;{ kf]nfl/6L ;'/Iff 5 eg] s'g} Iflt x'g] 5}g\ . sg]Szg kf]nfl/6LnfO{ 7Ls ug'{xf];\ . " df]6/ ;ls{6 k/LIf0f ug'{xf];\ -kfj/ ckmdf k|lt/f]w k/LIf0f_, olb sG6«f]n/ Ogk'6df plrt ef]N6]h 5 t/ df]6/ rn]ge g] of] k/LIf0f ug'{xf];\ . o;n] df]6/, kDk, s]a'n / :KnfO; sg]S;g;lxt ;du| df]6/ ;ls{6sf] cj:yf ;'lglZrt ug]{5 . " df]6/ ;ls{6 -P;L PDK;_ sf] ;~rfngdf /x]sf] s/]G6 k/LIf0f ug'{xf];\, o;n] df]6/n] kDkdf nufO/x]sf] an -6s{_ sf] ;+s]t u5{ . " df]6/df nf]8 ;fdfGo 5 eg] /fd|/L a'em\gsf] nflu sG6«f]n/n] pknAw u/fPsf] ;f+s]lts ljlzli6s/0f;Fu l/l8ªnfO{ t'ngf ug'{xf];\ . " pRr s/]G6 -ljz]if u/L kDk cf]e/nf]8 nfO6_ n] ;+s]t ug{ ;S5 M o kDkn] cToflws lylu|g] j:t' -afn'jf jf df6f]_ sf] ;fdgf ul//x]sf] x'g ;S5 . s'n 8fogflds x]8 -7f8f] pmrfO{ / kfOk 3if{0f n;_ ck]IffeGbf a9L x'g ;S5 . o kfgLsf] k|jfxdf cj/f]w x'g ;S5, kfOkdf a/km jf s]xL lylu|Psf] 5, kfOksf] efu s'lNrPsf], jf cf+lzs ?kdf eNe aGb 5 ls k/LIf0f ug'{xf];\ . o x]lnsn /f]6/ df]8]N; M olb kfgL &@ l8u|L kmx/]gxfO6 -@@ l8u|L ;]G6Lu]|6_ eGbf tftf] 5 eg] /a/ :6f6/nfO{ tGSofP/ /f]6/;Fu 5'g x'g;S5 -c:yfoL?kdf glalu|g]u/L_ . o x]lnsn /f]6/ df]8]N; M kDk ;'Vvf ePsf] x'g;S5 . /f]6/ vf]NgnfO{ df]6/af6 kDksf] :6f6/ -aflx/L cfj/0f_ nfO{ x6fpg'k5{ . obL /f]6/df s'g} /a/ c8lsPsf] -a;]sf]_ 5 eg] To;nfO{ abNg'k5{ . " cf]e/nf]8 z6 ckm -/ftf] aQL_ l/;]6, sG6«f]n/nfO{ ckm u/]/ cg ug'{ . s]lx ul/ kDkn] sd s/]G6 lnPsf] 5 eg], o; sf/0f x'g;S5 M o kDk x]8 -/f]6/ / ODk]n/ aLrsf] sg]S;g_ v/fa x'g nfu]sf] x'g ;S5, h;n] ;fdfGo eGbf 3'dfpg ;lhnf] x'G5 -ljz]ifu/L lylu|Psf] j:t'n] hfd ePsf] cj:yfdf_ . o 6«fG;ld;g / ljt/0f kfOkx?df r'xfj6 ePsf] x'g ;S5 h;n] nf]8sf] bafa sd ul//x]sf] x'G5 . o kDkn] klDkª\u ug{ g;ls/x]sf] x'g ;S5 / of] ;'Vvf g} ;~rfng ePsf] x'g ;S5 . 117 Training manual on Solar Irrigation Pumps | Test the float switch " If the controller indicates “source low” when the pump is in the water, the float switch may be at fault or incorrectly placed. " When the water level is above the float switch, the switch in the float switch makes contact. That causes the applied voltage to drop toward zero (LO signal). The controller interprets this signal as an ‘ok’ water level and allows the pump to run. " If the HI signal from the probe is triggered, the controller interprets this signal as a low water level and stops the pump. " To bypass the float switch (and activate the pump), connect a small wire between the float switch terminals in the controller. Reconnect the float switch correctly after the test. Do this only for testing purposes. " Restart the controller after disconnecting the float switch. If the pump runs, there is a fault in the float switch or the wiring. The wires may be shorted, open (broken), the moving part on the float switch may be stuck due to debris, or the float switch may be out of its desired placement. 118 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Ænf]6 :jLrsf] k/LIf0f " kDk kfgLdf x'Fbf olb sG6«f]n/n] æ;f];{ nf]Æ ;+s]t u/]sf] 5 eg] km\nf]6 :jLr q'6Lk"0f{ :yfgdf jf ;xL :yfgdf gePsf] x'g;S5 . " kfgLsf] :t/ obL km\nf]6 :jLrdfly 5 eg] km\nf]6 leqsf] sg]S;g aGb x'G5 . h;n] pkof]udf /x]sf] ef]N6]h z"Godf -LO ;+s]t_ emg{ ;S5 . sG6«f]n/n] pQm ;+s]tnfO{ &;xLÚ hn :t/sf] ?kdf AofVof u/]/ kDk ;~rfngsf] cg'dlt lbG5 . " olb k/LIf0fkl5 PrcfO{ -HI_ ;+s]t x'G5 eg] sG6«f]n/n] pQm ;+s]tnfO{ lgDg hn :t/sf] ?kdf AofVof u5{ / kDknfO{ /f]S5 . " km\nf]6 :jLrnfO{ gh/cGbfh ug{ -/ kDknfO{ ;qmLo agfpg_, sG6«f]n/df km\nf]6 :jLrsf] 6ld{gnx?aLr Pp6f ;fgf] tf/ hf]8\g'xf];\ . k/LIf0fkl5 km\nf]6 :jLrnfO{ k'gM ;xL ?kdf h8fg ug'{xf];\ . of] k/LIf0f p2]Zosf nflu dfq} ug'{xf];\ . " km\nf]6 :jLrsf] h8fg x6fPkl5 sG6«f]n/nfO{ k'g{;'rf? ug'{xf];\ . olb kDk rN5 eg] km\nf]6 :jLr jf jfol/ª\udf q'6L 5 eGg] a'lemG5 . tf/x? ;6{ ePsf] x'g ;S5, v'nf -r'Fl8Psf]_, km\nf]6 :jLrdf rNg] efu lxnf]÷c? kmf]x/n] c8\lsPsf] x'g ;S5, jf km\nf]6 :jLr cfkm\gf] :yfgaf6 ;/]sf] x'g ;S5 . 119 Training manual on Solar Irrigation Pumps | 10. Dos and Don’ts for Basic Maintenance " " Clean solar panels o Use a soft damp cloth to clean solar panels at least once a week. o If the panels are installed in a dusty environment, clean them frequently as necessary. " Keep the controller box dry and clean: o Make sure the insides of the controller box are clean and dry. o Since the controller box may be installed in the middle of the field, check for any insect nests that may have developed in hidden corners. " Avoid cleaning the panels during daytime: o It is advised to clean the panels in the morning or evening. o Cleaning the panels during the daytime may result in pump stoppage during cleaning due to shading. " Keep the panels shade-free: o This is especially applicable to panels installed in the field; over time bushes, trees or plants may grow around the panels causing shading. o Make sure objects in the area around the panels do not shade the panels any time of the day. " Don’t use water to clean any other part of the SIP except solar panels o Other components those house electrical systems should not be cleaned by water or wet cloth. o Always use a dry cloth to clean these components when the system is o. " Don’t connect or disconnect any wires of the system without consultation with a qualified technician o The DC and AC wires in SIP systems carry high voltages that can be fatal if mishandled. o Always contact qualified technicians to repair or dismantle the system. " Inspect the water source o Always inspect the water source for any debris or potential risk for the pump. o It is extremely important that the water pumped is clean and the pump is well protected and secured. 120 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf !)= cfwf/e"t -;fdfGo_ dd{tsf nflu ug{ x'g] jf gx'g] sfdx? " ;f}o{ KofgnnfO{ ;kmf ug'{xf];\ o leh]sf] g/d sk8fn] ;ftfsf] slDtdf Psk6s ;f}o{ KofgnnfO{ ;kmf ug'{xf];\ . o olb Kofgn w'nf] ePsf] jftfj/0fdf 5g\ eg] cfjZostf cg';f/ lg/Gt/ ;kmf ug'{xf];\ . " sG6«f]n/ aS;nfO{ ;kmf / ;'Vvf /fVg'xf];\ M o sG6«f]n/ aS;sf] leqL efunfO{ ;kmf / ;'Vvf /x]sf] ;'lglZrt x'g'xf];\ . o sG6«f]n/ aS; aflx/ /flvg] x'gfn], aS; leq sL/fn] u'F8 agfPsf] 5 ls hfFRg'xf];\ . " KofgnnfO{ lbgsf] ;dodf ;kmf gug'{xf];\ M o laxfg jf ;fFemsf] ;dodf dfq} Kofgn ;kmf ug{ ;'emfj lbOG5 . o lbgsf] ;dodf Kofgnsf] ;/;kmfO ubf{ 5fofFFn] kDk /f]lsg ;S5 . " KofgnnfO{ 5fofFF/lxt agfpg'xf];\ . o rf}/df h8fg ul/Psf] Kofgndf of] ;'emfa ljz]if?kdf nfu" x'G5 Ù Kofgnsf] jl/kl/ emf8L, ?v jf la?jf pld|P/ 5fofFF kg{;S5 . o Kofgn jl/kl/sf] If]qsf] s'g} klg j:t'n] lbgsf] s'g} klg ;dodf Kofgndf 5fFof gkf?g\ eg]/ ;'lglZrt x'g'k5{ . " ;f}o{ Kofgnafx]s ;f}o{ kDksf] s'g} efusf] ;/;kmfOdf kfgLsf] k|of]u ug{'x'Gg . o 3/df ljB'tLo k|0ffnLsf] cGo tTjx? kfgL jf leh]sf] sk8fn] ;kmf ug'{x'Fb}g\ . o k|0ffnL aGb u/]sf] a]nf ;w}+ ;'Vvf sk8fn] dfq} tTjx? ;kmf ug'{xf];\ . " s'g} bIf k|fljlwssf] ;'emfjlagf k|0ffnLsf] s'g} klg tf/nfO{ hf]8\g] jf x6fpg] sfd gug'{xf];\ o ;fo} { kDk k0| ffnLsf ] l8;L / P;L tf/df pRr efN] 6h] kj| flxt xG' 5 To;n} ] unt ko| fu] jf &ld;xof08nÚ 3fts xg' ;S5 . o k|0ffnLsf] dd{t jf eTsfpg -x6fpg_ bIf k|fljlwssf] ;Dks{ ug'{xf];\ . " kfgLsf] ;|f]tsf] k/LIf0f ug'{xf];\ o kDknfO{ xflg k'of{pg] s'g} eUgfjz]if jf ;DefAo hf]lvd kfgLsf] ;|f]tdf 5 sL ;w}+ k/LIf0f ug'{xf];\ . o kDk ul/Psf] kfgL cToGt} ;kmf /x]sf] / kDk ;'/lIft ?kdf ;+/If0f ul/g' cToGt} dxTjk"0f{ xf] . 121 Training manual on Solar Irrigation Pumps | " Inspect the output pipe o In some irrigation systems spanning over large field areas, it is observed that farmers block the output pipe of the pump after use and forget to unblock it in the next operation only to observe no water output. o Do not block the output pipe since this will result in pump overloading during operation causing it to heat which decreases its life. 122 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf " cfp6k'6 kfOksf] k/LIf0f ug'{xf];\ o 7"nf] If]qdf km}lnPsf s]xL l;+rfO k|0ffnLx?df ls;fgn] k|of]u ul/;s]kl5 kDksf] cfp6k'6 kfOknfO{ Ans ug]{ -aGb ug]{_ / csf]{k6ssf] ;~rfngdf kfgL gcfPkl5 dfq} Ans x6fpg la;]{sf] cjnf]sg ul/Psf 5g\ . o kfOksf] cfp6k'6nfO{ aGb ug]{ jf cj/f]w ;[hgf ug]{ sfd slxn] ug'{x'Gg o;n] kDk ;~rfngdf cfpFbf nf]8 a9]/ kDk tfTg uO{ o;sf] cfo" 36fpF5 . 123 Training manual on Solar Irrigation Pumps | 1. Annex: O&M template General information Project name: Date: Location: Name of O&M technician: Name of client representative: Contact number of client representative: Scheduled or unscheduled maintenance: ¨ Scheduled ¨ Unscheduled If unscheduled, describe the problem: SIP information Array size (Wp): Pump size (HP/kW): Type of pump: ¨ Surface ¨ Submersible ¨ DC pump ¨ AC pump Vertical head (m): Designed water output per day (L/day): Measured water output per minute (L/min): ……………. L/min Basic measurement – take a known volume of the buck- Measurement method: et and measure the time it takes to fill up. Take three samples of time readings. Use the average of the time ¨ Bucket measurement readings to calculate the flow rate in lpm. ¨ Flow meter ¨ RMU ¨ Others, specify For bucket measurement, fill in the following, Bucket volume: …………….. Liters Time (reading 1): ……………seconds Time (reading 2): ……………seconds Time (reading 3): ……………seconds Time of day: …………… Radiation: ……………W/m2 O&M maintenance checklist Make necessary rectifications to the SIP as the checklist proceeds Is there any physical damages observed in the solar ¨ Yes, describe: ……………………………… panels? …………………………………………………. Example: cracks, hotspots, etc. ¨ No Is the solar array clean? ¨ Yes ¨ No, describe the level of dirt:….…………… …………………………………………………. Disconnect the solar array from the controller and ¨ Yes, V measured: …………… oc check the V . Is the V of the array correct? oc oc ¨ No, V measured: …………… oc 124 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf During solar array diagnosis, were any of the following ¨ Faulty panel, describe:……………………… observed? …………………………………………………. ¨ Faulty cable, describe:……………………… …………………………………………………. ¨ Faulty cable connections, describe:.……...… …………………………………………………. Is there significant sag observed in the solar structure ¨ Yes, describe: ……………………………… that may cause mechanical stress on the solar panels? …………………………………………………. ¨ No Are all solar panel inter-wiring cables neatly tied? ¨ Yes ¨ No, describe:….…………………..………… …………………………………………………. Is the cable from the solar array to the controller prop- ¨ Yes erly conduit and insulated? ¨ No, describe:….…………………..………… …………………………………………………. Are all cable connections in the controller box properly ¨ Yes insulated and terminated? ¨ No, describe:….…………………..………… …………………………………………………. Is the controller box clean and dry? ¨ Yes ¨ No, describe:….…………………..………… …………………………………………………. Is the PV disconnector MCB working properly? ¨ Yes ¨ No, describe:….…………………..………… …………………………………………………. Is the lightning air terminal adequately supported and at ¨ Yes the appropriate height above the solar array? ¨ No, describe:….…………………..………… …………………………………………………. Is the solar array, controller box, SPDs and pump prop- ¨ Yes erly connected to the earth? ¨ No, describe:….…………………..………… …………………………………………………. Is the controller box operating as desired? ¨ Yes ¨ No, describe:….…………………..………… …………………………………………………. Is the cable from the controller to the pump properly ¨ Yes conduit and insulated? ¨ No, describe:….…………………..………… …………………………………………………. 125 Training manual on Solar Irrigation Pumps | If any changes were made to the controller settings, please describe the changes made: …………………………………………………. …………………………………………………. …………………………………………………. Is the pump adequately supported? ¨ Yes ¨ No, describe:….…………………..………… …………………………………………………. Is there any unusual noise observed during pump oper- ¨ Yes, describe: ……………………………… ation? …………………………………………………. ¨ No Is the non-return valve in the SIP system working cor- ¨ Yes rectly without leakage? ¨ No, describe:….…………………..………… Describe the quality of the water source: ¨ Clean ¨ Murky without significant debris ¨ Dirty water that is not suitable for pumps Is the pump intake free of debris and rotating properly? ¨ Yes Answer based on observation ¨ No, describe:….…………………..………… Conclusion Overall, have all rectifications been made during O&M, ¨ Yes and is the SIP operating optimally? ¨ No, describe:….…………………..………… List components that need replacement: 1. …………………………………………. 2. …………………………………………. 3. …………………………………………. 4. …………………………………………. 5. …………………………………………. 6. …………………………………………. ¨ None 126 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf Describe any pending rectifications necessary and 1. …………………………………………. explain why? ………………………………………………….. 2. …………………………………………. ………………………………………………….. 3. …………………………………………. ………………………………………………….. 4. …………………………………………. ………………………………………………….. 5. …………………………………………. ………………………………………………….. 6. …………………………………………. ………………………………………………….. Client representative Name: ……………………………………….. Signature: ……………………………………. O&M technician Name: ……………………………………….. Signature: ……………………………………. 127 Training manual on Solar Irrigation Pumps | cg';"rLM ;~rfng / dd{t ;+ef/ 6]DKn]6 ;fwf/0f hfgsf/L÷;"rgf cfof]hgfsf] gfd M ldlt M :yfg M cf] P08 Pd k|fljlwssf] gfd M u|fxs k|ltlglwsf] gfd M u|fxs k|ltlglwsf] ;Dks{ gDa/ M ;"lrt jf cg';"lrt dd{t M 6 ;"lrt 6 cg';"lrt cg';"lrt eP, ;d:ofsf] AofVof M ;f}o{ kDk ;"rgf P/] cfsf/ -Wp_M kDk cfsf/ -Hp÷kw_M kDksf] k|sf/ M 6 ;km]{; 6 ;Adl;{an 6 l8;L kDk 6 P;L kDk el6{sn x]8 -m_M l8hfOg ul/Psf] jf6/ cfp6k'6 k|ltlbg -ln6/÷lbg_ k|lt ldg]6df kmfn]sf] kfgLsf] dfqf -ln6/÷ldg]6_ M =============================ln6/÷ldg]6 cfwf/e"t gfk 3lglZrt cfotg ePsf] Pp6f afN6L gfksf] ljlw M lng] / eg{ nfUg] ;do gfKg'xf];\ . afN6Lg eg{ nfUg] 6 afN6Lsf] gfk ;do tLg k6s dfkg ug'{xf];\ . k|lt ldg]6 slt ln6/ kfgL cfpF5 eg] lx;fa lgsfNg tLgj6} ;dosf] 6 km\nf] ld6/ cf};t lgsfNg'xf];\ . 6 cf/Pdo" 6 cGo, pNn]v ug'{xf];\ Affn6Lsf] gfksf] nflu, tn eg'{xf];\, afn6Lsf] cfotg M=================ln6/ ;do M l/l8+u !============;]s]08 ;do M l/l8+u @=============;]s]08 ;do M l/l8+u #=============;]s]08 ;do -lbgsf] efu_============ /]l8PzgM===============8ANo'÷ju{ ld6/ 128 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf ;~rfng / dd{t ;+ef/ k/LIf0f;"rL k/LIf0f;"rL cufl8 a9\b} hfFbf ;f}o{ kDkdf cfjZos ;'wf/x? ug'{xf];\ ;f}o{ Kofgndf s'g} ef}lts Iflt cjnf]sg ul/Psf] 5 < 6 5, j0f{g ug'{xf];\============== pbfx/0f M qm]s -lrgf_ ePsf], x6:k6, cflb 6 5}g ;f}o{ P/] ;kmf 5 < 6 5 6 5}g, kmf]xf]/sf] :t/÷dfqf pNn]v ug'{xf];\ ================== sG6«f]n/af6 ;f}o{ P/]sf] sg]S;g x6fpg'xf];\ / eLcf];L 6 5, eLcf];Lsf] gfkM ============== k/LIf0f ug'{xf];\ . P/]sf] eLcf];L ;xL 5 < 6 5}g, eLcf];Lsf] gfk =============== ;f}o{ P/]sf] lgbfgsf] qmddf o;dWo] s'g} cjnf]sg ul/of] 6 Kofgndf q'6L, j0f{g ug'{xf];\========= < 6 s]a'ndf q'6L, j0f{g ug'{xf];\ ========= 6 s]a'n h8fgdf q'6L, j0f{g ug'{xf];\ ============= s] ;f}o{ ;+/rgfdf ;f}o{ Kofgnx?df oflGqs tgfj pTk Gg 6 5, j0f{g ug'{xf];\============ x'g;Sg] dxTjk"0f{ lzlyntfx? b]vfk/]sf 5g\ < 6 5}g ;f}o{ Kofgnsf] cGt/ jfol/ª\u s]a'nx? /fd|/L afFlwPsf]÷ 6 5 hf]l8Psf] 5 < 6 5}g, j0f{g ug'{xf];\========== ;f}o{ P/]af6 sG6«f]n/;Ddsf] s]a'n ;xL ?kdf OG;'n]6 6 5 ul/Psf] 5 < 6 5}g, j0f{g ug'{xf];\ s] sG6«f]n/ aS;df ePsf ;a} s]a'n h8fgx? /fd|/L 6 5 OG;'n]6 / aGb ul/Psf 5g\ < 6 5}g, j0f{g ug'{xf];\ s] sG6«f]n/ aS; ;kmf / ;'Vvf 5 < 6 5 6 5}g, j0f{g ug'{xf];\ s] lkeL l8;sg]S6/ Pd;LaL /fd|/L sfd u/]sf 5g\ < 6 5 6 5}g, j0f{g ug'{xf];\ s] nfO6lg+u Po/ 6ld{gnn] kof{Kt ?kdf 6]jf kfPsf] 5 / 6 5 ;f}o{ P/]dfly pko'Qm pmrfO{df 5 < 6 5}g, j0f{g ug'{xf];\ s] ;f}o{ P/], sG6«f]n/ aS;, P;kL8L / kDksf] cly{ª 6 5 /fd|/L hf]l8Psf] 5 < 6 5}g, j0f{g ug'{xf];\ s] sG6«f]n/ aS; ck]Iff cg';f/ ;~rfng eO/x]sf 5g\ < 6 5 6 5}g, j0f{g ug'{xf];\ s] sG6«f]n/b]lv kDk;Ddsf] s]a'n /fd|/L OG;'n]6 ul/Psf] 6 5 5 < 6 5}g, j0f{g ug'{xf];\ 129 Training manual on Solar Irrigation Pumps | sG6«f]n/sf] ;]l6+U;df s'g} kl/jt{g ul/Psf] 5 eg] To:tf] &&&&&&&&&&&&&&&&&&&. kl/jt{gaf/] pNn]v ug'{xf];\ &&&&&&&&&&&&&&&&&&&. s] kDk /fd|/L 6]sf];lxt 78\ofOPsf] 5 < 6 5 6 5}g, j0f{g ug'{xf];\ kDk ;~rfngsf] qmddf s'g} cJojxfl/s sf]nfxn 6 5 -cfjfh_ cjnf]sg ul/Psf] 5 < 6 5}g, j0f{g ug'{xf];\ s] ;f}o{ kDk k|0ffnLsf] gg3l/6g{ eNe -r]s eNe_ 6 5 ;xL ?kn] r'xfj6lagf sfd u/]sf] 5 < 6 5}g, j0f{g ug'{xf];\ kfgLsf] ;|f]tsf] u'0f:t/ pNn]v ug'{xf];\ M 6 ;kmf 6 t/ 6'qmflagf wldnf] 6 kDksf nflu c;'xfpFbf] kmf]xf]/ kfgL s] kfgL ;kmf 5 / kDk ;xL?kdf 3'd]sf] 5g\ < 6 5 6 5}g, j0f{g ug'{xf];\ lgisif{ ;du|df cf] P08 Pdsf] qmddf ;'wf/sf ;a} pkfox? 6 5 canDag ul/Psf 5g\ / ;f}o{ kDk /fd|/L sfd u/]sf] 5 < 6 5}g, j0f{g ug'{xf];\ x6fpg cfjZos ;fdfgsf] ;"rL agfpg'xf];\ M ! ============================ @ ============================ # ============================ $ ============================ % ============================ ^ ============================ 6 s'g} klg 5}g 130 | ;f}o{ l;+rfO kDkx?af/] k|lzIf0f lgb]{lzsf afFsL /x]sf] cfjZos ;'wf/ ug'{kg]{ s]xL 5 / lsg < ! ============================ @ ============================ # ============================ $ ============================ % ============================ ^ ============================ pkef]Qmf k|ltlglw gfd M ===================================== x:tfIf/M ======================================== cf] P08 Pd k|fljlws gfd M ============================= x:tfIf/ M ========================= 131 Training manual on Solar Irrigation Pumps | References/;fGble{s ;|f]tx? 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