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securing electricity availability in a pakistani school

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1. age cut Solar setting uses Solar as first priority power source Utility will be used only if solar in not available or battery voltage drops to low level warning voltage These setting can be used if batteries are full or nearly full and solar is shining well 52 61 Other option is utility first This option uses utility as primary source and so lar and battery only if utility is not available This option is default setting and most of the time best option to use It maximizes electricity time without grid and minimizes use of batteries and these together lead to maximum lifetime for batteries Only disadvantage with this setting is that during winter you cannot use all electricity coming from the solar panels Last option is same than first but there is possible to select other than low level warning voltage to go to the utility To change this option press enter button about 3 seconds Then there will be configurations Press dawn button to enter setting 01 Then press enter button to change setting Then press up or down to select wanted option Solar SOL utility Utl or solar with custom voltage SbU Then press enter again to confirm selection Pressing esc you can go to the main view again Charger source priority defines what source is primary source for charging batteries There is 3 options solar utility and both at the same time First option solar means that solar will charge batteries as first pri
2. E 6 625 10 34 s lt Ti Te REG s 111eV 16 10 J 1 1183 1076 m 1 12 um This result has important implications for the operation and efficiency of pho tovoltaic devices Photons with a wavelength greater than 1 12 pm contain insufficient energy to dislodge a valence electron in silicon hence photons with a wavelengths greater than 1 12 um will induce no photovoltaic effect in silicon Photons with a wavelength less than 1 12 jim possess more energy than is required to dislodge a valence electron and the difference between the band gap energy and the photon energy is absorbed as heat by the PV device Alternative Energy Systems and Applications 2010 The graphical represen tation in Figure 6 is useful to understand this l 0 Normalized power spectral density for 5760 K 0 8 Excess energy 0 6 Insufficient energy to dislodge an electron 2 2 5 3 Relative Intensity 0 4 0 0 5 l 1 5 Wavelength microns Figure 6 Photovoltaic effect Alternative Energy Systems and Applications 2010 It can be seen that the shorter wavelength includes more energy however because in the visible spectrum radiation is the most intensive which is the 18 61 reason why it contains about half of all energy That is why when energy from the sunshine is harvested materials with suitable band gap energy should be used Solar irradiation reaches PV modules in three different ways Direct diffuse and albedo The figur
3. Mounting System j imismanumms ea vi as e s saa tonsa asta MAKSA eE ham s vaa aa aeaa 37 9 Pl n forinstallatiOn si stsaasaasannta vesa ekassa nn ayake aak AkanaaNn Oana kaakkanuu ae aE Ei Ea ait 38 a TA MONA 101472100 1 AE E AINIIN IEE E SSN SIHTI 38 OEY P OSIUOT EE E minsaa kaava aa man husaaaeokala kalan S 38 9 3 Security and st nd rds s lt e saa ivan tn sana ma esnea tree ii Naa sa sae vakaa makaamaan 39 10 Buying Sgulpmenht sis ss sanissasaavastaaa aasta nra eae eia aie an 39 LL Unstallation WOrk vssensdcnscssssecavevantaselsscecendscveredantosnestaducbsassaestangens toupesustanetnsxacomntoeses 41 12 Plan for maintenance and operation oouossssse ea aa ana ae aa eanet 45 13 Results and conclusion ooosooss a a aa aan ae aa aa nana aan aa naan 45 REFERENCES ose cnsevasssaziava kann kaan epa kasa SU a TA VA ASHA SIN vahev E EEOAE S Kam MAUN E EE 48 APPENDICES 3a iiss cecccusieuas mave cveceus ests Lea ke rae ee iade aka a aidea aaraa 49 Appendix 1 User s guide for operation and maintenance ceeeeeeeeeeeeeeeeeee 50 Appendix 2 Direct and Latitude tilt solar map for summer 0 e eeeeeeeeeees 54 Appendix 3 Latitude tilt solar map for fall and winter 55 Appendix 4 Latitude tilt solar map for Spring uuuussss seen ae neen 56 Appendix 5 Table for Economical calculations osossssss sananen 57 Appendix 6 Table for Yearly average calculations eeses
4. of free electrons Renewable energy a user s guide 2008 If just pure silicon is used photovoltaic indeed takes place when light shines to it however electrons just randomly move in silicon and nothing useful is cre ated When a p n junction is made it forces electrons to go other side n type Then some conductive material can be added for example silver for both sides of a solar cell these electrons can be conducted to an electrical circuit and their power can be used Renewable energy a user s guide 2008 Bulk silicon is produced in long cylindrical ingots and these are sliced into fine wafers Once the wafers have been polished doped and added with an anti reflecting coating and electrical contacts applied they are referred to as cells Renewable energy a user s guide 2008 The majority of PV cells currently produced are Polycrystalline silicon In the past monocrystalline dominated however its share is coming down Together these dominate the markets Monocrystalline is more efficient especially in low light conditions but it is more expensive to manufacture Thin film is second generation technology and is made of other materials than silicon It can be flexible which is its main advantage however it is signifi cantly more expensive compared to the same power silicon based systems and that is why it is less used especially if the intension is to produce cheap elec tricity 21 61 5 2 Solar panels Sola
5. 55 C After stands for solar panels were designed according to the panels and they were ordered them from a local blacksmith Later Islamabad was visited to purchase batteries Because it seemed to be difficult or impossible to find flooded lead acid deep cycle batteries what is the most economical option it was necessary to use something else Even a seller of batteries did not know what he was selling He said that batteries were Gel type but when they were checked from internet the datasheet of the batteries was found and it proved that they were AGM batteries That thing was good because AGM was the second best option after flooded batteries Only disadvantage was that they are more expensive In other ways they are better that flooded batteries 41 61 Finally a local electrical shop was visited in Jhelum to buy wires breakers and other small things which were needed to install the system 11 Installation work After purchasing all equipment installation work was started The first a main electrical center was made Three breakers and a grounding bar was installed inside it After that the in verter the main electrical center and a breaker was installed onto a wall En suring that the inverter had enough space so that air can freely flow and cool down the inverter Then wiring work was started The first AC wires to the grid and the appliances were installed Then cables to the array and to the bat teries we
6. Government just does not seem to be very interested it can be guessed that mainly because high amount of capital is needed compared to fossil fuels and also lack of information because renewables have traditionally been more ex pensive way to produce electricity than fossil fuels Power station 2011 Total 17 71 Mtoe E Oil products 7 43 Mtoe Coal 0 06 Mtoe El Natural gas 6 40 Mtoe E Hydro 2 45 Mtoe HE Nuclear 1 37 Mtoe Figure 1 Share of fuels for electricity production International Energy Agency 2011 7 61 mun Electricity from power plants 10 00 mum Power plant losses mum Oil products input to power stations muun Coal to input power stations muun Natural gas input to power stations muun Hydro input to power stations mun Nuclear input to power stations 0 00 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 Figure 2 History of electricity production International Energy Agency 2011 If the development of electricity production is viewed in the past it can be seen that after 2006 yearly production has stayed approximately same At the same time population and economy has been growing so demand for electric ity is much bigger now Power and water ministry of Pakistan have estimated that there is 4500 5500 MW gap between demand and production That s why utility companies have exercised heavy load shedding to provide even some electricity for industry and households Neighboring countrie
7. If a grid fails just short periods of time this is a very good and economical solution to secure electricity availabil ity Problems start if the grid is off long periods Then battery capacity has to be bigger and that raises costs Most important and expensive part of UPS system is battery storage To study more about batteries see battery section in chapter 5 3 1 page 24 These sys tems are increasingly common in Pakistan and if considering all country this is not actually a solution to the problem The reason for this is that UPS systems actually increase electricity use from the grid therefore if more peo ple start to use these it leads to people without these being more time without electricity 9 61 2 2 Diesel and gasoline generator If conventional energy is discussed diesel or petrol generator is first option to produce electricity It is a relatively low investment and not too difficult to maintain Also generators are easily available and it is possible to run one in almost everywhere Biggest problem is price and availability of fuel And in remote areas users might have to carry fuel for long distances Additionally it is polluting and quite noisy and besides an engine needs some maintenance to keep its lifetime long and fuel cost low as possible In Pakistan diesel generator is probably the most common solution for the electricity shortage There are diesel or gasoline generators everywhere This is not good for
8. Some space from the roof was needed for the air to flow freely and cool panels 38 61 9 Planforinstallation 9 1 Location When installing solar panels it is important to see few matters First PV pan els should be installed so that they can gather as much solar energy at the time when needed The second very important issue is shading All shadows should be eliminated i e the panels should be installed so that shadows do not hit them If it is impossible the panels should be installed so that effect is minimized and limited to morning or and evening when insolation and elec trical loss and risk for hot spot caused by shadows is smaller In this case there was an open rooftop without any shadow available and because it was flat it was easy to orient the solar panels in whichever way it was wanted Batteries and other eguipment will be installed to a room under the roof That place has enough space and enough ventilation for them 9 2 Position Another matter is that during different time of day and season the sun shines at different angles To maximize the production the sun should be traced both horizontally and vertically This causes additional cost and it is complicated thus normally modules are mounted to fixed position If maximum annual production is wanted the panel should be mounted in an angle which is the same as the latitude and then they should be faced directly to the sun at noon i e to the south If summer pr
9. depending on what kind of electrolyte is used The most common is standard flooded followed by AGM absorbed glass mat and GEL type Sci ence amp technology of photovoltaics 2010 The most common type of battery is flooded because it gives the best price performance capacity ratio Its weakest point is that it needs some maintenance and care when transported Deep Cycle Battery FAG 2013 Gel batteries do not have liquid electrolyte but silicon An advantage about this material is that it is not spillable even though a battery is broken That is why it is easier to transport Disadvantages are that it has to be charged more slowly than a liquid one otherwise the battery will suffer permanent damage gassing gt electrolyte goes away and cannot be restored The same happens if the battery is discharged with too high a current Science amp technology of photovoltaics 2010 AGM batteries have all advances that gel however none of its disad vantages Only disadvantage is that when used at hot temperatures it suffers more than others Also it is 1 5 2 times more expensive than flooded but just slightly more than gel That means that this battery is very suitable for PV sys tems Not everyone needs these benefits and if adding water at times is not a problem for those flooded battery is the best because it is the most economical Deep Cycle Battery FAG 2013 26 61 One important thing to look is battery s life time Normall
10. 100 dischage cycles 350 Battery capacity kWh 24 Battery price 32000 219 Price per kwh 38 1 0 261 Appendix 6 Table for Yearly average calculations Additional liance O i N oO ju N oO ju N oO ju N oO ju N oO ju N oO ju oO ju oO ju oO D O ul ul Bulb Water heater Water cooler Water pump D O D O PSN g S 3 er Computer Fan Fan Fan Fan Monitoring system Television Television Microwave oven Bulb Fan Computer Heater Batteries Voltage V Time h Depth of cycle Battery capacity Ah Price Capacity Ah Number of batteries Real number Cost Solar array Panel power W Solar time day h Price Panel production Wh Number of panels Real number Cost 25 25 25 25 15 25 25 25 25 100 25 25 2000 200 800 100 83 100 80 80 50 50 63 210 45 1500 15 80 85 1000 6906 12 12 80 200 220 844 7 4 2 4 0 880 120 5 84 10001 16 7 16 1344 7 b O b N b d d d d GJ GI O md ad ad ad maail eh N ed eh aio eh eh th eh ili ND maili Power W No Average hrs day 6 5 0 35 NIE Mw wh Total Produced by PV Total by PV PV to load Inverter effiency Battery effiency Distribution efficiency Total PV demand Wh produced with panels Battery operation time Average op
11. Solar array Inverter Panel power W 120 Output voltage V 230 Solar time day h 3 5 Input voltage V 30 Price 84 Multiplier 5 Max power needed W 2972 Panel production Wh 8231 Number of panels 19 6 Real number 16 Cost 1344 61 61 Appendix 9 Table for spring and autumn calculations Appliance Bulb Bulb Bulb Bulb Bulb Bulb Bulb Monitoring system Television Television Microwave oven Bulb Fan Computer Heater Batteries Voltage V Time h Depth of cycle Battery capacity Ah Price Capacity Ah Number of batteries Real number Cost Solar array Panel power W Solar time day h Price Panel production Wh Number of panels Real number Cost Oo OS s9 100 25 25 2000 200 800 100 83 100 80 80 50 63 210 45 1500 15 80 85 1000 12 12 80 200 220 588 8 29 40 880 0 120 5577 9 3 16 1344 GJ N d d d d d G CO 9 ea aa eh aal ek ek AD ed aik oat td at ai at i NO i Average hrs day 6 5 1 12 5 5 7 5 4 2 12 0 2 18 Total Produced by PV Total by PV PV to load Inverter effiency Battery effiency Distribution efficiency Total PV demand Wh produced with panels Battery operation time Average op time with pv Inverter Qutput voltage V Input voltage V Multiplier Max power needed W Cost Average Whid
12. eguipment for 12 VDC however because their amount and availability is limited most stand alone solar systems are AC Inverters have developed much during the last decades In the past inverters were expensive and their efficiency was weak and guality of AC electricity was low Compared to grid connected systems inverters have less reguirements in stand alone systems The reason for this is that inverter uses batteries for en ergy source and that is why input voltage is relatively constant Also batteries can provide high currents if needed On the other side output voltage does not have to be matched to grid so voltage and freguency may vary Normally inverters produces sinusoidal wave form which is same than in grids then all eguipment can use it without problems 5 5 Combined electricity production Combined electricity production is also known as hybrid systems Many times it is expensive to design a solar system to produce all electricity because then the size of panels and battery bank must be big enough to cover even peak demand and or low insolation times If some additional power source can be used to give more electricity during peak demand the size of a battery bank and a solar array can be reduced as well as the initial cost of the system This also sorters the payback time of the system 29 61 When combining different energy sources it is to be considered how to con nect these sources to loads This is espe
13. inverter can has them internally to connect and disconnect the panels to the inverter and an inverter to loads and cables to connect the panels to the inverter and the inverter to a grid Principles of sustainable energy 2011 Interesting guestion is what happens to the grid connected solar system when the grid shuts down Because all grid tie inverters have a safety function they will shut down when the grid shuts down and electricity cannot be produced even if the sun is shining 23 61 Inverter Inverters used for grid connected systems have some reguirements They have to generate AC voltage which has same voltage and freguency than in the grid and the wave form also has to be same so they have to be sinusoidal Additionally it has to be able to operate with variable DC voltage and current coming from solar panels There are two types of methods in the markets to do that One is self commuted where the inverter s intrinsic electronics lock its output to the grid and line commuted where the grid signal is sensed and used to achieve syn chronization There are four main types according to their mode of use as well Electricity from sunlight 2010 e Central All electricity from solar panels comes to the main inverter and it converts it to AC and fed to the grid e String e Multi String e Individual Every solar module has its own inverter and they feed it to the grid Normally all grid tie inverters are MPPT max
14. sas ka k umaAv AN edesta E ITN aude daula AE eiia ENa 19 Del POUCH OM fetes a see aa Pannat maTi eeu paste Eo E Ta 19 5 2 S0lar panels 5 0 26 sos skececiscavs cesssadvcncdessvaeeiaacecss sn Ka puron AIRAA anal ena aaa niiae 21 5 3 Grid Connected System seniii n a Erani a EEE ora 22 54A Stand alone SY StOM ae sess ssccsscsssek aod eunechos suet cencsueaesssyeses spas cavacsosnvensdeuateosensseseeses 24 DAA Batteries miissen iaka eapi aieia a Eaa a a E E a 24 542 Charge comproller eesse tennder r enaena e Oera EE 26 5 43 IDVETTton eniris eia eaa a ae a EEr 28 5 5 Combined electricity production eesssessesesesesierrrresstssssrisrersissssresrerresses 28 6 Saying eleotrioity s isi ssa Taa eat uksi aasta E e Ka kaan TON SAINT ao aaaeei aknen 29 7 Electricity demand and economic analysis ooosssssses ean ee nan aa eanet 30 8 Design and parts Selections uouussss on a a a a n ae aa naa eaa e een 33 Sl Introduction signs sc esedecsedete osansa ka onc paavo EESE dad pen NP oN EAT E EEEE EEE EREE E Eies 33 8 2 SOLA ALA aeti deii niria k sn v saas E E ymv EE ENEE rE 34 S53 Battery Dankin eeo eie Ee san ceestssanctensauccossninceseactvedevreestios 34 8 4 Charge controller and inverter eseseeeeeeeeseessesresressrssrssresresressessresresressessese 35 5 3 Electrical COnnectiODS sses sodron t si t rassaa saatko inerse En EEEE eoa 36 8 6 Cable sizing and breakers uuouuson ene a aa aa niiina 37 8 17
15. that the most important is natural gas which is much used for transportation and to pro duce electricity There is also some coal which is not much used yet and of course Indus River with its braches has a huge potential for electricity produc tion which is just partially used so far Labor force is cheap in Pakistan but instability of the county has reduced foreign investments in the past The country is industrializing but lack of infrastructure especially current energy crisis slows down advancement The country is facing other problems as well Food and water security is big question now and in the future Waste disposal is huge problem currently Cities have open sewers and waste water goes directly to fields and rivers 5 61 Additionally dry waste end ups everywhere and recycling it is the job of poorest people Not organized but they try to make their living by looking something valuable Also social issues exist Level of education is low only few people graduate from universities and many do not get any education at all especially poor women Salaries are low but still country has some un employment and much underemployment That s why many people leave the country to seek better opportunities abroad The government uses a great amount of money for military mostly because it fears India so much Military expenses are about 3 1 of GDP That s a lot compared to education 2 4 or health care 2 5 For comparison in Fi
16. uw Sain S USAID Model estimater of monthly vera ge daly total aaston wing Bouts Korson A RET ar wed hon selte 2nd set ne ow arv ahon of oud Core auo opica depth preapsdle wte vapor dibeto Ana pheno arena sampled 41 4 An res chon pms Pakistan Direct Normal Solar Radiation Summer aal gt x fom uSsaip Model astimatas of monthly average daly total radiation using inputs poo so ee wet Nom satelite and sutace cos arvaksna of coud cower auasi opteg depth preaptable mutat vapor albedo semos phorc pressure and atene sampled a1 a Am res ohton 55 61 Appendix 3 Latitude tilt solar map for fall and winter Pakistan Flat Plate Tilted at Latitude w ot t gt ae w es N a fom Ey aw N S USAID Model astimatas of monthly vera ge daly total adaton using Bouts Se Gu wed Nom 5 elite 150 sete obi arv ahon o oud Core ae nh pte es depth preapsdle mutat vapor dibeto tmx phere eee sampled a1 4 Hee res chon pms gt or at t ne we ot t or Pakistan Flat Plate Tilted at Latitude N Winter Model estimates of monthly average daly total ra datisn using inputs Ge ed hon s halite mostre Oba arvaan of coud covet suns opteg depth preaptad le water vapor albedo emos pharc pressure and atene sampled a1 a Am res chien ne we 56 61 Appendix 4 Latitude tilt solar map for spring Pakistan Flat Plate Tilted at Latitude 4 ji Taib a gt USAID sctirates of mo
17. very obvious and the cheapest way is to shut down appliances if they are not needed If there is no one in a room it is totally unnecessary to keep lights or fans on If no one is watching television why to keep it switched on 30 61 The list goes on there are many possibilities to act To put this into practice it is necessary to teach the users about these issues Another way to save electricity is efficiency Many eguipment waste plenty of energy as heat just because their technology is old or also if insulation in a house is not good the generated heat or coolness goes away An advantage in energy saving is that generation can be decreased even more than what is actually saved because in this case the distribution losses are also smaller 7 Electricity demand and economic analysis First thing before designing a solar system or any other type of electricity pro duction is to figure it how much energy and power is needed To do that a list was made of all equipment in the house and estimation for how much they are used in average during different seasons Then solar maps were looked to see how much the sun is available during different seasons If good reliability is wanted production should match the consumption all the time This is just average but each day consumption and production varies so this needs to be taken into account as well 31 61 Table 2 Table for estimated electricity use yearly average Ave
18. achieving the best compromise between reliability and cost was the main pur pose Options to save electricity were also analyzed as well as reducing the demand for electricity and saving money and at the same time increasing the reliability of the system As a result of this theoretical framework the size of the photovoltaic array battery bank charge controller and inverter needed were calculated Additionally connections between these compo nents were designed cable sizes were calculated and security equipment was designed according to the customer s needs There were problems finding all needed equipment which is why minor changes to the plans had to be made Finally the working system was made despite these challeng es Together with all these electricity sources the system presented in this thesis is highly reliable to secure electricity and thus it can be said that the project result was successful and fulfilled the re quirements set for the thesis The hardest test will be the summer 2014 which will clearly test this system s capability Keywords Electricity production Sustainable development Photovoltaic Renewable energies Pakistan Miscellaneous 2 61 ir N JYV SKYL N AMMATTIKORKEAKOULU KUVAILULEHTI WIZ JAMK UNIVERSITY OF APPUED SCIENCES w7 Tekij t Julkaisun laji P iv m r Turunen Teemu Opinn ytety 22 04 2014 Sivum r Julkaisun kieli 61 Englanti Verkkojulkaisulupa my nne
19. allenging Trying to find a right compromise be tween performance reliability security and price is not usually easy But if the author of this thesis has understood it correctly this is the heart of engi neering work Additionally after designing everything it might be difficult to find wanted items especially in developing countries Then there is a need to apply and do things differently sometimes in a limited time and after every thing is installed and in operation there might be still something that does not work how it was planned and a problem solving is needed so there are many phases where thinking is an important part of the work That is why it is im portant to learn to think understand principles of key math and physics and learn to search information so that these kinds of barriers can be overcome Additionally when working internationally there might be cultural and lan guage barriers and these are something what must be dealt Anyway seeing a happy customer and the problem solved makes these projects worthy of doing them 48 61 REFERENCES Hodge B K P 2010 Alternative energy systems and applications p USA John Wiley amp Sons inc Kreith F And Kreider J P 2011 Principles of sustainable energy p USA Taylor and Fancis group Lynn P P 2010 Electricity from sunlight p Chichester John Wiley amp Sons inc Andy McCrea 2008 Renewable energy a user s guide p Ramsbury The Crowood Pre
20. and still are many Finnish indi viduals and organization that support the school financially Currently the school has a petrol generator to generate electricity during load shedding Petrol is very expensive and the generator is too small to provide all needed electricity and in addition it is inefficient Because of these reasons normally when load shedding exists they do not have any electricity only when there is special need they start the generator When solar wind and regular map are considered it can be seen that there is no wind or suitable rivers but plenty solar energy available Latitude tilt fixed solar panels generate an annual average of more than 5kWh day That is guite evenly divided to different seasons only winter is slightly weaker Because summer is the season when electricity is most needed and the grid is not available this makes solar panels a very suitable way to produce electrici ty Besides electricity is more needed during the day than night and obvious ly PV produces electricity during the day when the sun is shining Photovoltaic module gives energy only when the sun is shining onto it If it is cloudy energy the output drops to about from 1 3 to 1 10th from maximum and during the night there is no electricity at all Because of these facts an en ergy reservoir is needed If this situation is viewed from the economical point more accurately see eco nomic analysis in chapter 7 page 30 solar
21. ar Wind Hydro Low High High High cost production Maintenance Low Moderate Low needed Noise Very low i Very low Moderate Space nee Small Big Big i ded Installation Easy Moderate Difficult Difficult Environmetal Moderate High Low effects As can be seen renewable options are expensive to build but cheap to oper ate Their most significant disadvantage is that their production is directly related to environment If the sun is not shining the wind blowing or water flowing in a river there is no electricity 3 Selection of electricity supply for the school The school is located in the city of Jhelum It is located between Islamabad and Lahore and that is why it is guite far to the north however not at hillside The school has currently 5 rooms in 2 floors 3 are classrooms 1 is an office and the last one is for residents They are also expanding it to the 3rd floor and there will be 1 room more There are more than 100 students and 6 teachers in the school 15 61 The school is Christian but there are some kids from Muslim families as well Both boys and girls study in this school which is very uncommon in Pakistan where schools are separate for boys and girls They would like to have more students but there is no space for that The school started in 2008 with 8 stu dents so they have grown rapidly In the beginning Finnish state also sup ported the school financially There have been
22. at times in some locations Disadvantages are high ini tial cost and total dependence on the sun If sun is shining solar panels pro duce electricity and if not they produce nothing Also early morning evening or cloudy days they produce significantly less electricity because production is directly related to insolation level One of the best feature of solar panels is that they are very scalable The system can be very small for example just enough for charging a mobile phone and in the other end 100MW or even bigger power plants can be built to produce a huge amount of energy The cost per kW is not much higher for a small system than for a big one which is very good news for small scale production Pakistan Direct Normal Solar Radiation Annual KWhlm day 5 90 85 EE 75 80 Fre apes be wast areae samgied at 4 KKP res ohon Figure 3 Solar map of Pakistan yearly average direct Pakistan renewable energy society 2011 11 61 If solar maps for Pakistan are viewed it can be seen that there are good insolation levels available all aver the country So potential is huge for PV Photovoltaic and even CST Concentrated Solat Thermal as well Jhelum the city where the school is located is marked with black circles Seasonal solar maps are located in appendices two to four Federally Admin tered Thb Model astimatas of monthly average daly tota ra dutisn wi
23. ay 1050 125 50 300 82 5 187 5 100 50 300 20 450 600 280 2400 249 in bill 9666 7400 40 3866 4 30 0 9 0 75 0 95 5577 172 1 16 3 52 3 230 2014 300
24. cially important when talking about grid connected systems If our own power supply is to be used at the same time as the grid the system needs to be synchronized to the grid otherwise there will be serious problems If continuous electricity is wanted even when the grid goes off this scenario places even higher reguirements on the system The system needs to be synchronized at first to the grid and when the grid is off electricity should be produced independently eurselves and then when the grid comes back the system is to be synchronized again to its freguency There is another option if an inverter with grid connection option is not wanted to be used is the following a small delay should be allowed when changing energy supply to other Relays can do this so guickly that it is barely noticed and computers and other electrical eguipment are not turned off dur ing the process One option is also to supply some of the most important eguipment with solar energy all the time The rest take their electricity from the grid and when it is off then they are off 6 Saving electricity Saving electricity may sound something negative that it is to reduce the standard of living or similar In some cases this is true If electricity is not available it is not used and then it is saved however the living conditions are weakened Still there are some other ways to reduce electricity use without any negative effect on normal life First a
25. e 7 below presents this Normally direct radiation is the biggest portion but in cloudy days diffuse radiation is the only one because clouds block direct light Figure 7 Routes for solar irradiation Electricity from sunlight 2010 Additionally it is important to understand the way of the sun during different times of day and season This is important when energy is harvested from the sun because the earth is moving around the sun and because the axis of the earth is not in same line with the sun but inclined which causes that north side of the earth takes the most sunshine during the summer and south side least and during the winter in the northern hemisphere just the opposite The earth is rotating around its axis and this causes variation of day and night 19 61 Solar noon takes place in Jhelum is at 12 10 At that time the sun is at its high est point and also shines directly from south With this information it is possi ble to turn solar panels directly to south if a compass is not available 5 Photovoltaic system 5 1 Introduction Photovoltaic refers to the direct generation of electricity by solar irradiation Alternative Energy Systems and Applications 2010 Often it is shortened to PV Photovoltaic systems are divided into different sections based on the way how they are used The main distinction is that some are grid tie and others are independent There are also some special applications like water p
26. e charge controller needed to be large enough for there to be some capacity to add more solar panels if needed with out need to change the charge controller How many amps are needed de pends much on what the voltage in the panels is For example if there is 2000W solar array and the system voltage is 30V 2000W 30V 67A charge con troller is needed and if the system voltage is doubled the current 2000W 60V 33A can be halved An inverter has to be powerful enough to supply simultaneously different loads however not too big because that would increase cost both as initial price and operation because efficiency is lower when operating with low loads One important thing was to be able to use 800W water pump That needs about 2kVA inverter to start up and if there is some base load it has to be bigger than that It was estimated that 3kVA inverter is the most suitable It is not big enough to supply all possible loads simultaneously but it is enough for normal use 36 61 8 5 Electrical connections Solar panels will be connected to the charge controller and the charge control ler to batteries Solar panels will be connected in series and parallel Inverter will be connected also to batteries and then it supplies AC to loads Figure 9 Electrical connections 37 61 8 6 Cable sizing and breakers Cables cause some voltage drop and that drop is caused by current which is why cells and modules are normally connected in se
27. ging batteries 7 1 2014 solar panels installation was complet ed After that all solar panels were working and supplying electricity to the charge controller A sunny day at 12 o clock panels were checked if they were turned directly to south or not This was easy to see if their shadow was rec tangular or not Then they were adjusted exactly to south to maximize their yield 43 61 Figure 11 Main electrical center Figure 13 Installing solar panels 44 61 After installation of the system it was monitored so see how it worked and if there was a need to change the inverter s configuration Also the system was tested with the maximum load starting the water pump with basic load It was able to handle it without problems The performance of solar panels was tested on a sunny day The short circuit current for one type of panels was about 7A and other type it was slightly more than 6A Open circuit voltage was about 21 V for both type of panels This clearly tells that those panels have different power output despite the fact that the manufacturer announced that they are similar After couple of days there was a problem with the breaker connecting the so lar panels to the charger It had to be changed to other type and after that it has worked well Figure 12 Turning solar panels toward the south 45 61 12 Plan for maintenance and operation Solar systems do not need much maintenance and it is easy to o
28. head is high and the flow rate is quite good The government of Pakistan also support these kinds of activity and an Austrian company brings technology and knowledge for these systems Renewables in Pakistan 2010 Output of a hydropower plant is a product of four different factors the availa ble flow the head the force of gravity and efficiency of the turbine The force of gravity stays of course the same and most turbines are highly effective 50 85 therefore most important factors are the available flow and the head Available flow is discussed here because due to environmental reasons all riv er flow cannot go through the turbine Mostly head but also flow determines which type of turbine is to be used The most common turbine types are Pel ton Francis and Kaplan Pelton is suitable for high head and low flow rate sites Kaplan for low head and high flow rate and Francis is suitable for uses between these Renewable energy a user s guide 2008 If small scale production is discussed high head is economically more attrac tive since it is cheaper to build to generate the same power 14 61 2 6 Comparison between UPS generator solar wind and hydro Now if these options are considered there are some advantages and disad vantages when compared to each other The following table illustrates the most important of them Table 1 Comparison between UPS generator solar wind and hydro UPS_ Generator Sol
29. i muutoksia suunnitelmiin piti tehd mutta lopulta saatiin toimiva kokonaisuus Yhdess kaikkien s hk l hteiden kanssa t ss ty ss esitetty j rjestelm on luotettava turvaamaan s hk nsaatavuus ja siksi voidaan sanoa ett projekti oli onnistunut ja t ytti sille t ss ty ss asete tut vaatimukset Suurin testi j rjestelm lle tulee olemaan kes 2014 joka tulee n ytt m n mihin j rjestelm pystyy Avainsanat asiasanat S hk ntuotanto kest v kehitys aurinkos hk uusiutuvat energiat Pakistan Muut tiedot 3 61 Contents 1 TRtroduotion ssivsatass ea nanain aN UKN KANTA oe ae EEE EEA EEEE EER 4 2 Options to secure electricity supply uuouusssnss een ea a a aa e ae nananana 8 2 14 UPS samassa sn mae peak a esta aava topaaaadolalaaymmephnmalalalasstet sumua sntaleemvmmkshesian 8 2 2 Diesel and gasoline generator uuouoss nee aa an een e aan ana eaeen 9 PA SOIATsissrsanaka saata taan aaa avaan usta aan etua v Nu E E seal coacendaveseesbazecs 9 Dee WA E AI ITO AE EKS SISSIN PS 12 2 53 HY T POWEr svtilasvaa saamaansa mepaT ae ia ia E Ea E ET ES OEE SE 13 2 6 Comparison between UPS generator solar wind and hydro ssss 14 3 Selection of electricity supply for the school uuosuusme ena e na neen 14 4 Fundamentals of solar energy oooossusssn na aa a a eaa eaa eaa naa eaa eeaean 16 5 Photovoltaic Systemi sm saatas a
30. imum power point tracking type That allows taking as much electricity as possible out of panels and put ting it to loads and the grid Because inverters cannot generate exactly sinus oidal wave form this causes some distortion Normally this is indicated as total harmonic distortion which is often shortened to THD 24 61 5 4 Stand alone system 5 4 1 Batteries Stand alone systems are very different compared to grid connected Solar modules are the same or similar however more components are needed The most significant difference is that stand alone system cannot rely on any other energy source as a grid but it has to produce and store all needed energy As is generally known photovoltaic module gives electricity only when sun is shining Sometimes it is possible to connect a load directly for example to a pump because then a tank can be used as a reservoir and the pump operates when sunlight is available but in most cases electricity needs to be used even when the sun is not shining That is why a storage system is needed Most common are batteries which are presented in this subsection It is possible to use several kinds of batteries however the most common is lead acid type because they are the cheapest batteries for that purpose and their efficiency is relatively high compared to some other types Also these types of batteries have existed about 100 years in the market and during that it has been noticed that they are r
31. inverter cannot be used because it only works when the grid is on As economic analysis shows it is way too expensive to produce all needed electricity from the sun even though some operations are made to reduce electricity consumption which is why some kind of combina tion is needed Economic analysis shows that if life time expenses are compared solar energy is the cheapest then utility then battery bank and finally generator To get as cheap electricity as possible the sources should be used in this order if they are just available and using the two cheapest options should not be avoided which means that an independent system cannot be designed but utility should also be used The generator should be used just as an ultimate backup when all other sources fail which means that electrical connections might be somewhat complicated because three different sources are used This howev er is not going to be too complicated and this combination gives the best compromise for both reliability and costs initial and operation The method used for PV system sizing takes system operating efficiencies into account The model for this approach is from the book Principles of sustainable ener gy 34 61 8 2 Solararray Because solar power was decided to be used to produce electricity the size of the needed array is to be calculated next Calculations are presented in ap pendix six to nine The estimation was based to produce about 100
32. is the cheapest electricity life time expenses are considered however because storing electricity is guite expen sive it is better to use grid when it is available Combining solar and grid to 16 61 gether they provide cheapest electricity and then batteries are used only when either of these is not available which also reduces both initial and life time expense of batteries because smaller battery bank can thus be designed and it will be used in less deep cycles This setting provides a very good compromise between reliability and cost both initial and operation Because it was decided to use solar energy it is g00d to understand more in detail and next chapter provides further information on it 4 Fundamentals of solar energy Before practical applications for solar energy are discussed in this case photo voltaic systems it is good to gain some background information about solar energy Solar energy from the sun comes to earth in radiation form The energy of the photon can be calculated using following formula Alternative Energy Sys tems and Applications 2010 Where A 6 625 10 4 J sec Planck s constant and vthe frequency The fre quency wavelength A and speed of light c 3 108 m s are related as gt In Combining these formulas the wavelength of light can be determined that corresponds to the band gap energy of silicon 1 11 eV Alternative Energy Systems and Applications 2010 17 61
33. ity from sunlight 2010 The other type is shunt The difference compared to series type is that a switch is connected in parallel This leads to short circuiting the panels when the switch is connected Electricity from sunlight 2010 The disadvantage in both series and shunt type is that the panels are forced to operate at the same voltage than the battery or batteries This leads to the fact that most of the time the solar panels are not operating at their maximum power point and they are not producing as much as they could There is a solution to this problem and it is called MPPT maximum power point tracking This type of charger uses DC DC transformer so that the solar panels can operate at different voltage than batteries Also there is MPP tracker which tracks what the maximum power point of the solar panels is With this technology the most of the solar panel production can be taken into use With this type there is also a switch using PWM to limit the current going to batteries when it is needed Because this is more expensive than other types it is normally used in bigger systems where higher production compensates the price of the charge controller Nowadays it is also used under 1kWp sys tems Electricity from sunlight 2010 28 61 5 4 33 Inverter Solar panels produce DC and batteries store DC So far everything is good but because most eguipment are designed for AC thus an inverter is normally needed There is some
34. jamk fi SECURING ELECTRICITY AVAILABILITY IN A PAKISTANI SCHOOL Teemu Turunen Thesis April 2014 Degree Programme in Automation Engineering Technology communication and transport Pill E N el JYV SKYL N AMMATTIKORKEAKOULU Wd JAMK UNIVERSITY OF APPLIED SCIENCES sa 1 1 61 j FAAA JYV SKYL N AMMATTIKORKEAKOULU DESCRIPTION WW JAMK UNIVERSITY OF APPLIED SCIENCES w7 Author s Type of publication Date Turunen Teemu Bachelor s Thesis 22 04 2014 Pages Language 61 English Permission for web publication X Title Securing electricity availability in a Pakistani school Degree Programme Automation Engineering Tutor s Puttonen Pasi Assigned by Lamblamp education refinement Abstract The object of this thesis was to solve the school s problem in electricity availability which was the electricity grid in Pakistan was very unreliable The problem was solved by designing and installing an electricity back up system Besides this thesis contains a plan for its maintenance After making an estimation for electricity demand different options to supply the need were com pared and a hybrid system was selected which combines both UPS and Solar photovoltaic system to provide electricity The reason for this was that it was the most economical way to secure elec tricity availability It also had other advantages compared to other options Because 100 reliability was not necessary
35. lar electricity Even in the country like Pakistan where electricity price is low due to subsidies solar electricity is still cheaper than the utility thanks to the high insolation levels and low PV module prices Other good thing is that sunshine is available year around quite evenly so even off grid systems are attractive in some cases especially if the grid is not available One big challenge with solar energy is its initial cost Many persons could benefit much of it but they are too poor to buy a solar system There are 1 5 billion people living without electricity however most of them are too poor to buy even a small system of a 50W solar panel which could be enough for their needs Good thing is that now there are many financing options for them so that they can pay their system as they use it And thus they can replace their previous more expensive diesel generators or candles Learning experience This work was very independent the author of this thesis worked most of the time alone and there were not much other people to rely on during this pro ject Leading this project both the thesis report and the solar system design and installation has taught many things about project management in inter national environment Planning all phases from the predesign to a mainte nance plan and then put it all to practice and test the working system has been demanding but developing experience 47 61 Engineering work is guite ch
36. loat charging The problem is to know the actual state of a battery When a battery is not used for about an hour then the measured voltage indi cates the real state of a battery When a battery is used its voltage drops com pared to the A heavier drop leads to a larger voltage drop Also after discon necting the load the voltage remains lower and it takes some time to recover When the battery is charged the same happens however oppositely The more the battery is charged the higher the voltage is in the battery It also takes some time until the voltage drops to a real value after charging it One issue more is that battery voltage is affected by temperature For example if battery voltage is 12 5V at 25 C it is at different state of charge than 12 5V at 15 C 27 61 That is why more sophisticated charge controllers has a temperature compen sation as well Electricity from sunlight 2010 There are different kinds of charge controllers and they need to be further ex plained before being able to choose an adeguate one The most traditional is the series charge controller It is simple and cheap so it has been much used especially in small systems A switch to connect a source to a battery is in series so that is why it is called series type When it becomes nearly fully charged the current must be limited and it is done by cutting on and off the incoming power in high freguency using PWM Pulse Width Modulation method Electric
37. ng pouts Garrod hon stelte ands utace cts arv ators of cloud covet auai op tes depth preaipeadle water vapor tota emas phasic pressure arvelet a1 a ake ras ohi Pakistan Flat Plate Tilted at Latitude S USAID Wierd v Figure 4 Solar map of Pakistan yearly average tilted at Latitude Pakistan renewable energy society 2011 12 61 2 4 Wind Another option is wind energy The cost of producing wind energy is falling as well as the cost for solar energy which is mostly due to bigger and bigger mills In some situations if there is enough wind available small scale wind production may be a good alternative to produce electricity It can also be a good addition for solar energy especially in places where solar radiation is not divided egually between seasons For example in Germany Winter is the windiest season and naturally the sun shines least during winter The windiest places are in the south near the coast however there are also other good places for wind energy as can be seen if on the map below Pakistan 50 m Wind Power amp Baluchistan lt X nr oF DGN Wind spoeds are based on an elevation of 500 m and 8 Webul k value of 1 8 A an N S USAID Figure 5 Wind map of Pakistan Pakistan renewable energy society 2011 13 61 2 5 Hydropower There are many rivers in Pakistan and that is why there is plenty of hydro power available especially in the north where the
38. nland the same figures are 8 9 for health care 6 8 for education and just 1 5 for military CIA 2012 There is also relatively high inflation nearly 10 budget deficit and balance of trade is negative When county faces challenges in basic services like food water and energy it is hard to raise living standards of average people and additionally security is weak in many parts of the country There are conflicts in Afghanistan border Kashmir Balochistan and security in old capital Karachi is also weak If all these issues are put together it can be seen that Pakistan is struggling with huge challenges to give decent life for its citizens and without foreign investments and help it is difficult to get out of poverty and solve environ mental issues 6 61 Energy situation in Pakistan now and in the near future According to IEA International Energy Agency Pakistan produced in 2011 sligtly less than half of its electricity by oil major part of it imported one third came from natural gas hydro nearly 15 and others less than 10 In other words Pakistan relies much to fossil fuels to supply its electricity hydro be ing only renewable resource Pakistan s goal is to increase the use of renewa ble energies other than hydro to 5 by 2030 Renewables in Pakistan 2012 It can be believed that Pakistan can reach much more than that because prices for renewable energy have come down and most likely will continue to do so
39. ntily sewage daly total radution wing mputr ae aan Ces ed hon stelte and Sete Cbd arv lkora of ond Corel Sunol opts depth preaptsdle water vapor teto tas phenc press eee sampled 41 4 Hee res chon pms 57 61 Appendix 5 Table for Economical calculations Economics Solar energy life time cost Currency Rupee Euro Currency Rupee Euro Exchange rate 146 1 Exchange rate 146 1 Total price for a solar system 440000 3013 70 Best case scenario Maintenance cost avg year 0 00 Amount of electricity in life time kWh 82125 Fuel price per litra 110 0 75 Cost of solar panels and mounting 150000 1027 Est generator electr savings 611309 4187 04 Price per kwh 1 83 0 013 Electricity price per kwh 9 2 0 063 Est electricity savings year 0 00 Loss and price of inverter included Amount of electricity in life time kWh 45625 Pay back time years 0 72 Cost of solar panels 190000 1301 Yearly intrest rate Price per kwh 4 16 0 029 Net present value Half of production not used Electricity price per kwh SA 0 063 Amount of electricity in life time kWh 22813 Cost of solar panels 190000 1301 Price per kwh 8 33 0 057 Generator tank 4 Time produced 800W 1 5 Price per kwh 366 7 2 51 Battery storage life time cost 30 dischage cycles 1800 PV produced electricity 1667 2 Battery capacity kWh 24 Battery price 32000 219 Price per kwh 24 7 0 169 50 dischage cycles 1000 Battery capacity kWh 24 Battery price 32000 219 Price per kwh 26 7 0 183
40. o do it 51 61 Batteries Batteries used in this system are sealed lead acid AGM batteries They are maintenance free and that s why does not need much maintenance After some time there might appear corrosion between battery poles and connect ors If that happens you should turn off inverter and then the battery circuit breaker Then you can disconnect battery cables and clean connections They have limited lifetime and after 3 5 years use they should be replaced with new bank of batteries Worse thing to do for batteries is leave them with out use at low charge state so best maintenance is to keep them fully charged and not leave them without use for long period of time several months Charge controller inverter The inverter is the brain of the system It has many useful functions In ini tial page it shows the state of the system It indicates if Utility is available and what is the voltage If appliances are supplied by utility there is passby text in top of the screen It also shows if solar panels are online and charging bat teries The inverter has also many configurable settings Most important of them in normal operation are output source priority and charger source priority In normal operation there is no need to change any other parameters Output source priority defines which is the source of power to use as first option There are 3 different selections Solar utility or solar with battery volt
41. oduction is to be optimized then the angle should be decreased by 15 degrees from latitude If winter production is the most important then the angle should increase by 15 decrees 39 61 Because more energy is needed during summer but the current charger can take only 50 amps ti was decided to install one half of the panels at latitude angle 30 degrees and the other half for summer optimum 15 degrees 9 3 Security and standards When working in developing countries like Pakistan it is easy to think that Atleast we do not have to care about standards this however is absolutely wrong It is actually more important to work according to standards and good practices because locals may know little about electricity On the other hand it may be difficult or impossible to find all needed eguipment and tools to fulfill European standards however at least it is important to do installations as well as possible 10 Buying eguipment A budget was made for all eguipment for everything for 450000 rupees 3000 Lahore was visited to buy the most important eguipment PV panels charge controller inverter and batteries It was tried to find these devices in Jhelum however they were not available there at the wanted guantity and price Only couple solar panels and small charge controllers were available at relatively high price Only basic things like wires switches etc are available there In Lahore an electronics market
42. oes not mean that the sun shines just 5 hours day but that there are equivalent 5 hours at 1000W m This helps to estimate solar panel s output For example a 1kWp system gives about 5BkWh day in a location with 5 solar hours In practice a solar panel produces about 11 hours if where are 12 hours daylight however most of the production comes during noon from 10am to 2pm Also solar 22 61 panel s efficiency is not constant but it normally drops when radiation is low er Polycrystalline drops less than monocrystalline however the difference is not significant If accurate values for production are to be calculated the oper ating temperature needs to be known In history solar panels were mostly used for charging batteries nowadays less than 5 of the panels go to these systems and the rest are used for grid con nected systems so that is why many panels use even a higher amount of cells in series and they produce higher voltages as well When solar panels are connected in series or parallel or combination of these it is called an array Because solar panels can produce just hundreds of Watts in many cases it is necessary to use more panels and build these arrays 5 3 Grid connected system As noticed in the previous chapter that grid connected systems dominate nowadays it is useful to study them more detail A grid connected PV system contains only solar panels a mounting system for them an inverter breakers the
43. of elec tricity which the grid cannot supply In winter this leads to a too high produc tion and in summer the production is too little however this is a good com promise Taking into account the losses about 2kWp solar array was needed as well as it was needed to know how to connect this to a charge controller 16 pes of 120W panels or 12 pcs of 160W panels could be used and then they could be connected to four in series and these sets in parallel or some other combination that is compatible with the selected charge controller 8 3 Battery bank Batteries are the most expensive part of installation if lifetime expenses are considered Also if a storage system for long time is to be bought it is the most expensive initial investment as well which is why it is important to se lect adeguate kind of batteries and adeguate amount of capacity Also there should be capacity large enough to provide electricity when needed Too deep cycles are not desirable in normal use because that will reduce batteries life time significantly It was decided that 12 hours is long enough average opera tion time with average load Then 4 200Ah 12V or 8 100Ah 12V batteries were need The battery type should be liguid lead acid deep cycle and if it is not available then AGM and final option is Gel 35 61 8 4 Charge controller and inverter A charge controller is needed that is capable to take input from the solar array and use that to charge batteries Th
44. ority and if it is not available then utility will charge batteries This setting is recommend ed most of the time because this takes most from solar panels of these op tions Second option utility uses utility as primary option to charge batteries and solar only if utility is not available This setting is not recommended if solar panels are installed Last option uses both solar and utility at the same time to charge batteries This setting is recommended if solar first cannot provide enough electricity during summer 53 61 To change this option press enter button about 3 seconds Then there will be configurations Press up or dawn button several times to enter setting 16 Then press enter button to change setting Then press up or down to select wanted option Solar CSO utility CUt or solar and utility SnU Then press enter again to confirm selection Pressing esc you can go to the main view again For changing other parameters and solving problems read user s manual of the inverter If you need to remove the inverter for reparation or maintenance you can connect the house directly to the grid by removing the wire coming from the AC input breaker and installing the wire to there coming from the AC output beaker Only gualified person can do this work 54 61 Appendix 2 Direct and Latitude tilt solar map for summer Federally Pakistan Flat Plate Tilted at Latitude w
45. perate There is a guide for users for this particular system Most of the tips are general but there are of course some instructions which are applicable just for this system or exactly similar The inverter s user manual was used to get instructions for its configurations The guide is located at appendix 1 User s guide for maintenance and operation 13 Results and conclusion Result of this thesis was a small off grid solar plant which gives electricity during that time when the grid is out of order A 1 8kWp solar array was built with a 400Ah 24V battery bank Then there is a combined UPS solar charger and inverter to handle the solar array the batteries and the grid This should be able to provide electricity for the school most of the time during grid failures The system was installed in January 2014 and there are now couple months operational experience how it works So far it has worked as expected and supplied electricity during grid failures The summer will be the hardest test in many ways and it will test how well this system actually works It is estimated that it is not able to provide enaugh electricity all the time at least without heavy reduction in the electricity use This was deliberate decision because the budjet and the size of the roof did not allow to design a bigger solar array 46 61 This theoretical background and the practical system presented in this thesis shows how huge potential there is for so
46. r domestic use because otherwise it would be too expensive for poor people But because there is so much solar available in Pakistan and PV price is so low that solar system provides electricity even cheaper than that Expecting 25 years life time for panels it means that price is something between 0 015 0 06 kWh depending on how it is calculated the best way gives 0 03 kWh This gives about 10 years payback time for grid tie systems Grid tie system is not want ed here instead electricity is to be produced when it is not available from the grid If just fuel cost for current petrol generator is observed each kWh cost about 2 5 Effective diesel generators fuel costs for each kWh is about 0 6 and then the price for the generator and its maintenance is to be added on top of that which makes it a very expensive way to produce electricity Storing electricity is also guite expensive because batteries are expensive and have guite a limited lifetime The life time cost for storing electricity depends on how deep cycles are used for example if an average 50 cycles are used its cost is about 0 18 per kWh Then the electricity has to be produced somehow and add its cost to the price Calculations for these figures in this chapter are presented in appendix 5 33 61 8 Design and parts selections 8 1 Introduction In previous chapters everything necessary to solve this problem has been dis cussed As it is known grid tie
47. r panels or modules are made of solar cells Because a solar cell produces a relatively high current but low voltage they are connected in series to get more higher and useful voltage Traditional solar panel designed for 12V bat tery charging contains 36 cells all connected in series This gives about 21V open circuit voltage and 17V at maximum power point at standard testing conditions Hotter operating temperature reduce both voltages however MPPV Maximum power point voltage still stays above 15V This is enough for 12V battery what reaches about 14 5V when fully charged Science amp tech nology of photovoltaics 2010 Solar panel output is normally indicated in standard testing condition It is 1000W m at 25 C operation temperature 1000W m is a condition when the sun shines directly at noon from clear sky Most of the time radiation level is lower than that The current produced by solar panel is directly related to so lar radiation When radiation drops current also drops Voltage also drops but just slightly When the temperature changes the output of solar panel also changes When temperature increases the voltage drops also At the same time the current increases but only slightly so the power drops To estimate a solar panel s output during a day the term solar hour is used It indicates how much solar power is available in a day or some other unit For example near the eguator typical amount is 5 solar hours This d
48. rage Whiday Additional If high reliability is not as important as low cost then a good balance between these should be found In customer s case this was the thing so a yearly aver age consumption and production was set as a starting point The target was to produce 100 of the average demand for load shedding period Then it was calculated how big a solar array was needed This is explained in the chapter 8 1 on solar array As can be seen from the table the average daily electricity use is about 13kWh Lightning being the biggest user 3 3kWh then fridge 2 4kWh and fans 2 2kWh The fridge is very old and that why it uses much electricity Ways to reduce this are looked into the energy saving section chapter 6 32 61 Economic analysis Oil prices have gone up and because oil is limited resource and in long period demand grows more rapidly than supply and that s why it is expected that oil price continue to rise And because Pakistan has very limited oil reserves it has to rely heavily on imports and have to pay high price At other hand all components for solar electric production have gone down last 30 years and trend is expected to continue Right now PV panel prices are very cheap be cause production is higher than demand mainly because china has invested very much to production This sounds that it is good time to investment solar energy In Pakistan electricity price currently 0 06 kWh is subsidized fo
49. re installed After that the batteries were in stalled to each other two in series and two set of these in parallel and then Figure 10 Inverter main electrical center and battery bank these to the inverter After these installations the inverter was quickly tested just with the batteries It started well and worked as supposed Because mounting equipment were not ready yet it was decided to connect the invert 42 61 er to the grid and the appliances and use it as UPS device until the mounting system became ready and PV array could be installed as well The house did not have any grounding so it was made as well A hole was dug into the ground near the house and about 5 meters big size naked copper wire was installed there The grounding is only used for the solar system to ground the mounting eguipment to protect panels from lightning and then for the inverter Separate wires for the electrical center and for the mounting eguipment were used A day after the first stand was ready solar panels installation started Three solar panels were installed to a stand and then two of them were connected in series and then they were connected to the charger inverter The system was switched on and solar panels started to produce electricity Later the second stand became ready and more solar panels were installed After that half of the panels were in operation The charger was configured to use solar as first priority for char
50. ries so that voltage drop can be minimized Using too small cables causes significant voltage and pow er loss and can heat the cables which causes higher losses Too big cables are expensive and though they reduce voltage drop they are not economically attractive Therefore a compromise is needed and according to literature 2 are normally the used value for permitted voltage drop at maximum current A tool was made in an Excel sheet to calculate the cable sizes for copper wires and it was used to select correct cables It was recommended to use 32A breaker for input AC so it was decided to use it for both input and output and a decision was made to use 60A breaker for solar panels and 125A for batteries 8 7 Mounting system Because summer is the season when electricity is most needed the production was to be optimized for that period It was decided to use fixed angle and then face the panels directly to the south The city is located at 32 latitude which was the base for designing the mounting system To divide production it was decided to install half of the panels to 30 degree angle which is good for yearly average and the other half to 15 degree angle which is best for summer After buying panels accurate measures for mounting were now available Be cause half of the panels were somewhat smaller than others two different models were needed for frame and because two different angles were neces sary their stand had be different
51. s have offered to sell electricity to Pakistan but so far the government has not approved the offers Though there are rumors in Pakistan that the government has started to buy electricity from China In summers situation gets worse because then demand is highest The author of the thesis had his own experience how elec tricity comes and goes randomly and it happens quite often even in winter when electricity is less used The government has a plan to end load shedding by the year of 2017 but there is still at least 4 years left to suffer because of this problem And if our government does not always keep its promises it is not a surprise if they are not able to solve the problem by 2017 The citizens are guite unhappy for the situation and rightly so because it makes everyday life much more difficult 8 61 2 Options to secure electricity supply 2 1 UPS There are several options to secure electricity supply Most of them produce electricity and one is based on storing electricity There is a brief introduction to them in this chapter Just options for small scale production are presented UPS Uninterruptible Power Supply is maybe the first option to consider if there are problems with energy supply UPS is noiseless or almost noiseless and easy to operate because it switches back up on and off automatically when needed and ability to charge batteries If the batteries are maintenance free this system is also maintenance free
52. seeseeseeeeteeeeeeeee 58 Appendix 7 Table for summer calculations eeceesesseeeeeeeeeeeeeeneeesaeeeseeeees 59 Appendix 8 Table for winter calculations cc eseesseesceeseeeeceeceeeeeetaeeeaeeeaes 60 Appendix 9 Table for spring and autumn calculations 200 0 ee seeeeeeeeeeeeeeeeeeeeee 61 4 61 1 Introduction There is a school in Pakistan They have used a grid to supply their electricity need but because there is an energy crisis the government of Pakistan calls it load shedding in Pakistan they need a solution for the problem electricity comes and goes several times every day Because the government is unable to solve the problem in near future they have to do something by themselves They had to make some kind of backup system against load shedding In this thesis it is aimed to find an adeguate solution for the problem by designing a proper system and then install it and make a plan for its maintenance There are more than 180 million people living in the area of 796 000 km about same as Finland and Sweden together Most of this area is desert and that is why population is concentrate to live near the Indus River and its branches Pakistan is the second largest Muslim majority country in the world and the religion has a large effect on society and everyday life Pakistan does not have large natural resources most important being land for cultivation and half of the labor force works in agriculture After
53. ss Ltd P Jayarama Reddy P 2010 Science amp technology of photovoltaics p India BS Publications Renewables in Pakistan Status and trends 2010 Government of Pakistan Ac cessed on 8 October 2013 Retrieved from http www mowp gov pk gop index php q aHROcDovLzE5Mi4xNjguNz AuMTM2L21vd3AvdXNicmZpbGVzMS9maWxIL3 VwbG9hZHMvcHVibGIjY XRpb25zL3JlcGsucGRm Deep Cycle Battery FAG 2013 Northern Arizona Wind amp Sun Accessed on 2 January 2014 Retrieved from http www solar electric com deep cycle battery fag html Solar Wind Maps 2011 Pakistan renewable energy society Accessed on 3 January 2014 Retrieved from http www pres org pk category resource solar wind maps Rocket battery datasheet 2013 Global Battery Co Ltd Accessed on 6 January 2014 Retrieved from http www smsolar net files Rocket 20ESC200 12AGM GEL pdf Energy balance of Pakistan 2011 International Energy Agency Accessed on 18 January 2014 Retrieved from http www iea org Sankey index htmlff c Pakistan amp s Balance Facts of Pakistan 2013 Central Intelligence Agency Accessed on 27 January 2014 Retrieved from https www cia gov library publications the world factbook geos pk html User manual for Cherry 15 15 Inverter Charger 49 61 APPENDICES Appendix 1 User s guide for operation and maintenance Appendix 2 Direct and Latitude tilt solar map for summer Pakistan renewa ble energy society 2011 Appendix 3 Latitude til
54. t solar map for fall and winter Pakistan renewable energy society 2011 Appendix 4 Latitude tilt solar map for spring Pakistan renewable energy society 2011 Appendix 5 Table for Economical calculations Appendix 6 Table for Yearly average calculations Appendix 7 Table for summer calculations Appendix 8 Table for winter calculations Appendix 9 Table for spring and autumn calculations 50 61 Appendix 1 User s guide for operation and maintenance Solar system includes 5 main components Solar panels an inverter batteries grid supply and supply to appliances There are 4 breakers to connect and disconnect these to the inverter Solar panels Solar panels don t need much maintenance Only thing is that they should be cleaned if there is dust or bird dropping on modules because these cause some output loss During dry season you should clean panels with a wet cot ton rag once a month or every second month butif it is very dusty then you can do it twice a month During rainy season cleaning is not needed because raining water does the job Other thing what you can do is to measure with a multimeter that solar panels are in good order You can do this once a year or if there is notice drop in pro duction you can do it also Their open circuit voltage should be more than 40 volts in almost any conditions Short circuit voltage should be about 7 amps in direct sunlight Don t take any measurement if you are not sure how t
55. the economy because the price for electricity increases signifi cantly and fuel is mostly imported which worsens trade balance even more 2 3 Solar UPS systems or diesel generators are not the only possible options There are alternative options renewable energies are plenty available in Pakistan Most obvious of them is the energy from the sun There is plenty of sunshine all year around Best places are in the center and south Near the ocean there is less sunshine and in the north is the worst place in Pakistan for solar energy however compared to many other countries Pakistan has good resources of solar energy all over the country The cost of solar panels has decreased during last 30 years and there is no rea son for this trend to stop in near future A few years ago industry set a goal to achive 1 pW peak Watt production cost by 2013 In 2013 best manufactur ers can get as low as 0 5 pW Solar panels cost about same everywhere but installation costs vary much between different countries but it possible to ob 10 61 tain less than 1 pW for installed grid tie systems This means that there are more and more economically profitable applications for solar systems Economy is one issue however solar panels have other advantages as well They are soundless easy to install for many different places and in buildings they can be almost invisible It does not need any fuel or maintenance expect cleaning panel glasses
56. time with pv Inverter Output voltage V Input voltage V Multiplier Max power needed W 1050 125 50 300 82 5 187 5 100 50 300 20 450 600 600 600 280 2400 249 200 960 960 300 10 1512 735 225 750 13096 6548 30 0 85 0 75 0 95 10001 96 0 11 4 21 9 230 24 2728 58 61 Average Wh day All lightning 3315 Fans 2230 59 61 Appendix 7 Table for summer calculations Appliance Power W No Average hrs day Average Whiday Bulb 25 T 6 1050 Bulb 25 1 5 125 Bulb 25 2 1 50 Bulb 25 1 12 300 Bulb 15 1 55 82 5 Bulb 25 1 LAS 187 5 Bulb 25 1 4 100 Bulb 25 1 2 50 Bulb 25 1 12 300 Bulb 100 1 0 2 20 Bulb 25 1 18 450 All lightning Bulb 25 2 12 600 3315 Water heater 2000 1 0 0 Water cooler 200 1 12 2400 Water pump 800 1 0 5 400 Fridge 100 1 24 2400 Computer 83 1 3 249 Computer 100 1 2 200 Fan 80 6 6 2880 Fan 80 3 15 3600 Fan 50 3 6 900 Fans Fan 50 1 0 5 25 7405 Monitoring system 63 1 24 1512 Television 210 1 3 5 735 Television 45 1 5 225 Microwave oven 1500 1 0 5 750 Bulb 15 2 6 Fan 80 1 6 Computer 85 6 1 Heater 1000 1 0 in bill Total 19591 9700 Batteries Produced by PV 70 Total by PV 13714 Voltage V 12 Time h 12 PV to load 40 Depth of cycle 80 Inverter effiency 0 85 Battery capacity Ah 200 Battery effiency 0 75 Price 220 Distribution efficiency 0 95 Capacity Ah 1263 6 Total PV demand Wh 20379 Number of batteries 6 3 Real number 4 0 produced
57. tty X Ty n nimi S hk n saannin varmistaminen pakistanilaisella koululla Koulutusohjelma Automaatio Ty n ohjaaja t Puttonen Pasi Toimeksiantaja t Lamblamp education refinement Tiivistelma T m n opinn ytety n tarkoitus oli ratkaista koulun s hk n saatavuudessa ollut ongelma joka oli se ett Pakistanin s hk verkko oli eritt in ep luotettava Se tehtiin suunnittelemalla ja asentamalla s hk n saatavuuden varmistava j rjestelm Lis ksi tehtiin suunnitelma sen yll pitoon S hk nkulutuksen arvioinnin j lkeen vertailtiin erilaisia vaihtoehtoja tarpeen t ytt miseksi ja p dyttiin aurinkos hk n ja UPS j rjestelm n yhdistelm n Syy t h n oli se ett se oli taloudellisesti j rkevin tapa turvata s hk n saatavuus Lis ksi sill oli muita etuja vaihtoehtoihin verrattuna Koska 100 luotettavuus ei ollut v ltt m t nt tavoitteena oli paras kompromissi luotettavuuden ja hinnan v lill My s vaihtoehtoja energian s st miseksi arvioitiin koska siten voidaan v hent s hk energian tarvetta ja siten lis t j rjestelm n luotettavuutta ja s st rahaa T m n teorian pohjalta laskettiin aurinkokennoston akusto latauss din ja vaihtosuuntaaja tarvit tava koko Lis ksi suunniteltiin kytkenn t n iden komponenttien v lille laskettiin kaapelikoot ja suunniteltiin turvalaitteet asiakkaan tarpeiden mukaan Tarvikkeiden hankinnassa tuli ongelmia joten pien
58. ugged and reliable Flooded wet lead acid batteries are familiar because every car has one Batteries for cars have been designed to give a high current for a short period of time engine start and after that they will be charged to full again For this reason they have thin plates and high surface Science amp technology of photovoltaics 2010 In PV systems the case is different Normally the load is relatively low and occasionally the battery can be fully discharged for example if it is cloudy many days Because car batteries cannot handle several full discharges they will die too quickly and are not suitable for PV systems Of course if yeu ean get old car batteries are available for free they can be considered as an option however they have to be changed quite often In most cases this is not an op tion thus car batteries have to be abandoned and another solution needs to be 25 61 found Fortunately there are batteries designed for this purpose and they are called deep cycle batteries They are designed to last several full discharges without a huge impact on their capacity These batteries have thicker plates which is why they are also heavier compared to same capacity car batteries Always when a battery is used chemical reactions take places and causes that its plates are consumed little bit That is why batteries with thicker plates last longer time These lead acid deep cycle batteries are divided into three differ ent types
59. umping They all have some different component however there is at least one thing in common They all harvest energy directly from the sun And that is why PV systems have at least one common component and it is also the most im portant one solar panel There are of course many kinds of solar panels avail able in this thesis the focus is on the one currently most used silicon based Today s PV modules are based on semiconductors Electrically there are three main types of materials conductors insulators and semiconductors Conduc tors have a free electron and that is why they conduct electricity well The sol ids with covalent bond are insulators electrically Science and technology of photovoltaic 2010 Between these there are semiconductors These do not have a free electron at low temperature however they conduct some electrici ty at room temperature Most important semiconductors are silicon and ger manium Science and technology of photovoltaic 2010 20 61 Generally silicon solar cell is a wafer of p type silicon with a thin layer of n type silicon applied to one side N and p type silicon can be created by dop ing the silicon to produce the reguired variety and bringing them together creating p n junctions The first silicon must be purified to very pure and then some phosphorus is added to make n type silicon which has a surplus of free electrons If some boron is added p type silicon is gained which has a deficit
60. was visited and solar panels and other things were available there with a guantity guality and price which was wanted Only problem was that the most suitable batteries were not available The so lar panels 150W 12psc were purchased and they cost less than what was estimated The process to buy them took several hours and the shop where they were bought did not have enough panels so they arranged part of them 40 61 somewhere else Rests of them were slightly different physically but manu facturer was the same and they had the same rated electrical values Then a hybrid inverter was purchased which combined an inverter a charge controller and an UPS device That cost the same than each could cost indi vidually Only problem was that the charger is series or shunt type and only 50A 24volts That causes some loss in efficiency Despite these disadvantages this was actually quite good machine for the purpose Now there was no need to make a separate control when to use what type of energy source because the inverter has internal switches and pro grams for it Additionally it can be configure to operate as wanted If there is a need to prioritize solar or grid charging use solar or grid as primary source etc even thou not everything is possible At least inverter is pure sine wave and 3kVA power so these features were what was wanted Peak efficiency is only mentioned and it is 90 Operation temperature range is from 0 C to
61. with panels 51 8 Cost 880 0 Battery operation time 7 6 Average op time with pv 11 9 Solar array Inverter Panel power W 120 Output voltage V 230 Solar time day h 5 5 Input voltage V 30 Price 84 Multiplier 4 Max power needed W 3265 Panel production Wh 20379 Number of panels 30 9 Real number 16 Cost 1344 60 61 Appendix 8 Table for winter calculations liance Power W No Average hrs day Average Whi day Bulb 25 K 6 1050 Bulb 25 1 5 125 Bulb 25 2 1 50 Bulb 25 1 12 300 Bulb 15 1 5 5 82 5 Bulb 25 1 15 187 5 Bulb 25 1 4 100 Bulb 25 1 2 50 Bulb 25 1 12 300 Bulb 100 1 0 2 20 Bulb 25 1 18 450 Bulb 25 2 12 600 Water heater 2000 1 1 1 2200 Water cooler 200 1 12 2400 Water pump 800 1 0 35 280 Fridge 100 1 24 2400 Computer 83 1 3 249 Computer 100 1 2 200 Fan 80 6 0 0 Fan 80 3 0 0 Fan 50 3 0 0 Fan 50 1 0 0 Monitoring system 63 1 24 1512 Television 210 1 3 5 735 Television 45 1 5 225 Microwave oven 1500 1 0 5 750 Bulb 15 2 6 Fan 80 1 6 Computer 85 6 1 Heater 1000 1 0 1 Total 14266 Batteries Produced by PV 40 Total by PV 5706 4 Voltage V 12 Time h 12 PV to load 30 Depth of cycle 80 Inverter effiency 0 9 Battery capacity Ah 200 Battery effiency 0 75 Price 220 Distribution efficiency 0 95 Capacity Ah 869 0 Total PV demand Wh 8231 Number of batteries 4 3 Real number 4 0 produced with panels 81 6 Cost 880 0 Battery operation time 11 0 Average op time with pv 16 4
62. y it is measured in cycles One cycle means discharging 100 charged battery to 20 charge level and then charge it back to full again This is a normal cycle but manufacturers may give other depth of cycles as well or several different for example Rocket battery datasheet has life time for 30 50 and 100 deep cycles Rocket bat tery datasheet 2013 Life time mentioned in years for batteries is many times given with assumption of 10 or less deep daily cycles For example there is a battery with 600 cycles at 80 and it is used daily like that it can be assumed that it lasts 600 365 1 6 years and with 10 discharge it may last 5000 cycles which means 5000 365 13 7 years which is a huge difference with the same battery Carefulness is reguired when some manufacturer promise for exam ple 12 years life time and some other just 5 years It has to be figured out ahat the assumptions behind these figures are Deep Cycle Battery FAG 2013 5 4 2 Charge controller The task of a charge controller is of course to charge a battery or a bank of bat teries As simple as it sounds there are few important issues how to charge the battery depends on its stage When a battery is empty it can be charged with high current and when it is reaches its full charge the charging current should be smaller Finally when the battery is full it is charged just slightly to keep it full These steps are also called constant current stage constant voltage state and f

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