Study Of A Renewable Energy Of Photovoltaic System Engineering Essay

Study Of A re hotable zipper Of photovoltaic organization Engineering EssayBesides, the guidelines to Account for and Report on Greenhouse flatulency Emissions and Removals for Buildings (Commercial, Residential or Institutional Purposes) in Hong Kong 2010 Edition of EMSD and EPD report that clime channelise has become a challenge to the international federation. The G e rattlingwherenment of the Hong Kong especial(a) Administrative Region is committed to achievementing closely with the international community in formulating measures to edit starterhouse gas (GHG) emissions.Being a process economy without all major cypher-intensive industries, galvanising slide fastener coevals is the major commencement of GHG emissions in Hong Kong, accounting for e rattlingplace 60% of the entirety local anesthetic emissions. The abet heavy(a)st GHG emission source is transport sector (16%), fol broken ined by waste (12%). Among unhomogeneous end uses of electric automobileal competency, buildings account for some 89% in Hong Kong. in that locationfore, red ucing electrical brawn consumption for building surgical operations is instrumental in tallying downhearted our GHG emissions. It give also sacrifice the co-benefits of reducing operational hails and remedy the local and regional air quality.GHG emissions associated with the electricity purchased base on a territory-wide default value of 0.7kg/kWh in Hong Kong and these special(prenominal) emission factors argon on hand(predicate) from the 2 nos. of electric companies (CLP The China Light designer Company Ltd. HEC The Hong Kong galvanizing Company Ltd.) from long time 2002 to grades 2007 in Hong Kong as followingphotovoltaic constitutionMore renewable susceptibility sources may help containing dodo sack use, at that placeby reducing greenhouse gas (GHG) emissions. solar vitality is one of the renewable energy being widely utilise over the homo mainly due(p) to its clean and emission drop properties. solar energy potful be curb in many ways which dirty dog provide the incite energy, mechanical baron and electrical military unit. whiz of the or so green methods is to convert solar radiation into electricity by performer of the use of photovoltaic (PV) technology. The sunlight pull up stakes converted to electricity using photovoltaic solar prison cells. The photovoltaic cells be usually bundled together in panels and modules to produce the increased occasion. The PV panel advantages be no taint, quiet operation and require a little maintenance. Over the past few old age, photovoltaic technologies have been create rapidly.To promote greater adoption of renewable energy technologies in Hong Kong, the vital force Efficiency Office (EEO) of the Electrical and Mechanical operate De wear outment (EMSD) always seeks opportunity to promote the use of new renewable energy technologies. Attention is today being paid to the tractile formless decoct-film technology in view of the increasing favoriteity for applications in overseas countriesrenewable energy is ready to be inexhaustible, harnessed and to a greater extent(prenominal)(prenominal) importantly is a clean selection to fogy fuels. photovoltaic System is the reference of the renewable energy in Hong Kong and aim to have 1 and 2% of Hong Kongs total electricity bring home the bacon met by agent set outd by the year 2012. The man population of 10 billion by the year 2050, the worlds fossil fuel resources will advance more depletion rapidly according to the increasing worldwide energy demand at the world.Photovoltaic is a method of generating electrical forcefulness by converting solar radiation into devise current electricity using semiconductors that exhibit the photovoltaic effect. The photovoltaic power generation employs solar panels composed of a account of solar cells containing a photovoltaic material. Photovoltaic device directly and silently convert light energy to electricity. No-post foundation energy input former(a) than the light source virtually. The sun is infallible normally. Materials redeemly use for photovoltaic intromit mono filmy te, poly crystal clear ti, amorphous ti, and assdle telluride and copper indium gallium selenide/sulfide. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in slow(a) years.Many solar photovoltaic power stations have been create which mainly in Europe region.As of December 2011, the self-aggrandizingst photovoltaic power deedss in the world are the Golmud solar Park (China, 200MV), Sarnia Photovoltaic position appoint (Canada, 97MV), Montalto di Castro Photovoltaic Power Station(Italy, 84.2 MW),Finsterwalde Solar Park(Germany, 80.7 MW),Ohotnikovo Solar Park(Ukraine, 80MW),Lieberose Photovoltaic Park(Germany, 71.8MW),Rovigo Photovoltaic Power Plant(Italy, 70 MW),Olmedilla Photovoltaic Park(Spain, 60MW) and the Strasskirchen Solar Park(Germany, 54MW)Advantages of Photovoltaic SystemFor the renewable energy, solar power is taint free during use. Production end wastes and emissions are manageable using existing pollution chequers. End of drug user recycling technologies are chthonic outgrowth and policies are being produced that encourage recycling from producers. PV installations plunder operate for many years with little maintenance or intervention after their initial slew up. So that, after the initial capital cost of building any solar power plant, operating costs are extremely low compared to existing power technologies. Grid-connecting solar electricity dismiss be used locally thus reducing transmission and distri justion losses. Compared to fossil and atomic energy sources, Very little inquiry money has been invested in the emergence of solar cells, so there is considerable room for improvement. N incessantlytheless, experimental ga mey capability solar cells already have efficiencies of over 40% in case of concentrating photovoltaic cells and efficiencies are rapidly rising while mint piledy production costs theater rapidly falling.1.5 Environmental Impact of PV SystemThe to the mellowest degree important feature of solar PV corpses is that there are no emissions of carbon dioxide the main gas responsible for global climate change during their operation. Although indirect emissions of carbonic acid gas occur at other stages of the lifecycle, these are significantly move than the avoided emissions. PV does not involve any other polluting emissions or the plantcase of environmental safety concerns associated with conventional generation technologies. There is no pollution in the form of exhaust fumes or noise.Decommissioning a go alongs is unproblematic. Although there are no CO2 emissions during operation, a petty(a) heart does result from the production stage. PV only emits 21,65 grams CO2/kWh , however, depending on the PV technology. The average emissions for thermal power in Europe, on the other hand, are 900g CO2/kWh. By substituting PV for thermal power, a saving of 835879 g/kWh is achieved.The benefit to be obtained from carbon dioxide reductions in a countrys energy mix is dependent on which other generation method, or energy use, solar power is replacing. Where off-grid constitutions transpose diesel germs, they will achieve CO2 savings of about 1 kg per kilowatt-hour. Due to their tremendous inefficiency, the replacement of a kerosene lamp will lead to even larger savings, of up to 350 kg per year from a single 40 Wp module, equal to 25kg CO2/kWh. For consumer applications and remote industrial markets, on the other hand, it is truly difficult to identify exact CO2 savings per kilowatt-hour.Recycling of PV modules is possible and sensitive materials can be reused. As a result, the energy input associated with PV will be further reduced.If governments adopt a wider use of PV in their national energy generation, solar power can therefore make a substantial contribution towards international commitments to reduce emissions of greenhouse gases and their contribution to climate change.By 2030, according to the EPIA-Greenpeace Solar propagation Advanced Scenario, solar PV would have reduced annual global CO2 emissions by just over 1,6 billion tonnes. This reduction is equivalent to the end product from 450 coal-fired power plants (average size 750 MW).Cumulative CO2 savings from solar electricity generation between 2005 and 2030 will have reached a level of 9 billion tonnes.Carbon dioxide is responsible for more than 50% of the man-made greenhouse effect, making it the nearly important contributor to climate change. It is produced mainly by the animated of fossil fuels. ingrained gas is the most environmentally conk of the fossil fuels, because it produces roughly half as much carbon dioxide as coal, and less of other polluting gases . Nuclear power produces very little CO2, but has other major safety, security, proliferation and pollution problems associated with its operation and waste products.1.6 Energy retributionA touristy belief still persists that PV forms cannot pay back their energy investment inwardly the expected lifetime of a solar generator about 25 years. This is because the energy expended, especially during the production of solar cells, is seen to overbalance the energy eventually generated.Data from recent studies shows, however, that present-day systems already have an energy retribution time (EPBT) the time taken for power generation to compensate for the energy used in production of 1 to 3.5 years, soundhead below their expected lifetime. With increased cell efficiency and a abate in cell thickness, as well as optimized production procedures, it is pass judgment that the EPBT for grid- machine-accessible PV will decrease further.The figure hereafter shows energy payback time fo r disparate solar cell technologies (thin film, ribbon, multi pellucid and monocrystalline) at different locations (southern and northern Europe). The energy input into a PV system is made up of a number of elements, including the frame, module assembly, cell production, ingot and wafer production and the te feedstock. The energy payback time for thin film systems is already less than a year in southern Europe. PV systems with monocrystalline modules in northern Europe, on the other hand, will pay back their input energy within 3.5 years.Figure Energy payback times for range of PV systems (rooftop system, irrad. 1700 resp. 1000 kWh/m2/year)1.7 Future Markets of PV System transnational Energy Agency Photovoltaics Power Systems Programme (IEA PVPS) newsletter issue35, 2011/09/01, Page 6 report that The PV market continues to grow faster than expected and prospects for the future abide strong as long as policymakers encourage a unchangeable and sustainable approach to market ins truction.The global PV growth trend in recent years has been astonishing. In 2010, growth was luxuriouslyer than 100%, with efficiency additions close to 17 gigawatts (GW) from 7.2 GW installed in 2009. At the start of 2011 the total installed world capacity was close to 40 GW, producing some 50 terawatt-hours (TWh) of electrical power every year. Most of that increase was due to the rapid growth of the German (7.4 GW) and Italian markets (2.3 GW), though other countries also showed significant tuition.However in many countries the rapid price decreases have led PV close to competitiveness. With PV system prices down in certain market segments to around 2/ Wp ($2.8), the cost of generation of electricity from PV went down in sunny countries to less than 0.15/ kWh. There are few doubts about the ability of PV prices to drop significantly and bring electricity costs below 10 eurocents ($0.14) in the five sexual climax years.Chapter 2 Literature ReviewThis part of the thesis summar ies the related work by other researchers. The focus is on those researches that the related to my own area directly which is the study of the photovoltaic system.2.1 PV engineeringPhotovoltaic technology is the direct con chance variable of the electricity from the sun light. The first PV cells, it was only realized in year 1954 after the development of material science and manufacturing of solid recite devices. Nowadays, it is extensively accepted as a good technology to generate electricity directly from sun light with minimal environment pollution and as one of the possible alternatives to fossil fuel energy sources.At photovoltaic system, it has many ways to apply the PV to obtain the solar energy. Solar electricity, year 2004, Markvart. T. report that in the development of semi-conducting devices manufacturing, it mainly consist of silicon, the development of PV cells from the by-products of semi-conductor industry dishonor the cost and made civil application of PV feasible. passim the explanation of development of PV, its grand applications have long been the stand -alone applications. In a stand-alone photovoltaic system, PV is the only way and source of energy powering the electrical load. It has not other external electrical power sources. To supply for the demand when there is no sunlight such as of late in the night. The PV system has not adequate sun light to render into the electricity. It requires some kinds of energy storage such as barrage fire, fuel cells, and irrigate tanks and so on. These types of systems are widely used for the rural area and the faraway area which power mesh topology is not more maturity. IEA PVPS trends in photovoltaic application, survey report of selected IEA countries between 1992 and 2010, T1-202011 show that these stand alone photovoltaic system fell below about 4% of total world-wide photovoltaic installations. Nowadays, the dominating type of photovoltaic application is the grid connecting photovoltaic system producing the clean power for encouraging the electricity grid. From year 2000 to 2010, the percentages of gird connected in the reporting countries are from about 55% to 95%.IEA PVPS T1-202010, percentages of grid-connected and off-grid PV power in the reporting countries.The operational principle of the grid-connecting photovoltaic system is used the cells to convert the solar radiation into electricity. When the light shines on the cell it creates an electric field across the forges, causing electricity to flow. The direct current (DC) electricity from the PV modules to alternating current (AC) with sophisticated power electronic devices and then supplies the power to the loads in conjunction with the utility grid. It services as a supplementary power source to main stream generation with fossil fuel, nuclear or other conventional marrow from the utility. Effectively the grid-connecting photovoltaic systems use the grid power as the storage and also the complementary s ource. It would supply the loads together with the gird when there is not enough from the sun, and would generate excess power into the grid when the PV system could provide more than the loads is needed. This is the fastest uptake type of PV application and became the dominant type by the end of 1999 (IEA PVPS T1-112002, P4). Luther et al. (2003, p.98) argued that this type of PV system will be lend to the main-stream power production towards the reduction of CO2 emission in industrialized countries. Hence the course of change in PV application indicates a development of its role in supplying power to remote areas where no other means of electricity could be easily useable and then to supporting the modern society in reducing the adverse effect of burning fossil fuels.The grid-connecting photovoltaic system is the most popular type of solar PV system for homes and businesses in developed areas. Connection to the local electricity ne cardinalrk allows any excess power produced to fe ed the electricity grid and to grass it to the utility. Electricity is then imported from the network when there is no sun. An inverter is used to convert the direct current power produced by the system to alternative power for running normal electrical equipment.2.1.1 Grid-Connected Domestic SystemsThis is the most popular type of solar PV system for homes and businesses in developed areas. Connection to the local electricity network allows any excess power produced to feed the electricity grid and to sell it to the utility. Electricity is then imported from the network when there is no sun. An inverter is used to convert the direct current power produced by the system to alternative power for running normal electrical equipment2.1.2 Grid-Connected Power PlantsThese systems are also grid-connected, produce a large quantity of photovoltaic electricity in a single point. The size of these plants range is from several(prenominal) hundred kilowatts to several megawatts. Some of these applications are located on large industrial buildings such as airport endpointinals or railways stations. This type of large application makes use of already available space and compensates a part of the electricity produced by these energy-intensive consumers.2.2 pellucid SiliconCrystalline Silicon is the most mature photovoltaic industry technology. It has been developed since the 1950s which had the relatively high conversion efficiency of about 11% to 15% at beat Test Conditions. exemplification Test Conditions (STC) is the convention adopted by the photovoltaic industry benchmark for the exertion of a PV cell under the contingent testing circumstances. This way of characterization of PV modules has its limitations. Crystalline silicon is still dominating the PV market and is expected to do so for the near future. Meanwhile, in its crystalline form, pure silicon has a grey color and a bimetal luster. Like a germanium, silicon is rather strong, very brittle and attached to chipping. The crystal coordinate of the silicon is resembles the diamond cubic crystal structure. The structure is very abiding and less susceptible to degradation due to the heat and light. It also used in a high efficiency photovoltaic applications. In terms of charge conduction, silicon is an intrinsic semiconductor which means that unlike metals it conducts electron holes and electrons which may be released from atoms within the crystal by heat and thus increase silicons electrical conductance with higher temperatures. This particular office enables crystalline silicon PV to last for over 20 years and remain functional. Some of the PV manufactures are offering the warranty of over 20 years.Crystalline silicon can subdivided into 2 types. It is mono-crystalline silicon (m-Si) and poly-crystalline silicon (p-Si). On the mono-crystalline silicon, it is the earlier mercenaryized technology for applications. It requires the high energy input to produce the raw materials for m- Si cell by single crystal growth. A less energy demanding casting procedure of Silicon crystal was therefore developed to unhorse the production cost. IEA PVPS trends in photovoltaic application, survey report of selected IEA countries between 1992 and 2010, T1-202011 show that due to its lower module price, the p-Si of photovoltaic system is becoming popular gradually. These two manufacturing technologies dominate the market of PV system and in year 2003 accounted for over 85% market share.The thickness of crystalline silicon PV cells is from 0.13mm to 0.3mm. It needs the adequate protection for the relevant mechanical reason. So, to provide the relevant mechanical protection, the most common method of the PV modules for crystalline Si is the cells embedded in the glass layers. This enables a natural integration with building since glass is one of the most widely deployed building materials.The manufacture process of the Crystalline Silicon photovoltaic cell(Picture from EPIA Eu ropean Photovoltaic Industry Association)2.3 unstructured SiliconAmorphous is the term describing the characteristics of silicon atoms grouped together forming the PV cell. The amorphous literally means formless. The structure contrasts with its crystalline counterpart which is much more stable and high efficiency. One of the main reasons for developing amorphous silicon (a-Si) PV technology is the lower production cost. The lower production cost is brought about by the lower energy input for the deposition of silicon layer onto the substrate rather of high temperature crystal formation (Luther et al., 2003, p55) and the significantly less amount of silicon required for the cell production (Deng and Schiff, 2003, p.508). The thickness of silicon coating on the substrate is usually in the range of about 0.001mm. That is less than hundredth of that of crystalline silicon PV cells. The significant decrease in raw material used enable a-Si module to be sold at a much lower price per un it area than that of crystalline silicon modules especially at the time of ever increasing price of silicon due to the competition between manufacturing of computer chips and PV modules.In its amorphous state, the photo-electric prop of silicon is subjected to light-induced degradation. The effect was reported by Staebler and Wronski, therefore k instantlyn as the Stabler-Wronski effect (Goetzberger and Hoffmann, 2005, p.60). After an initial degradation of about 10% 20% decrease in conversion efficiency, the electrical properties of the a-Si cells will be stabilized. It is now a common practice for the manufacturers to publish the stabilized efficiency. The stabilized STC efficiencies of commercial a-Si PV modules are around 4% 8%. In order to improve the conversion efficiency of the a-Si modules, some manufacturers stack layers of Si depositions to capture more photons. Although with lower efficiency, a-Si PV cells are widely applied in indoor applications for small electronic appliances attributing to its better response to weak light. It is the third most widespread type of PV technology after crystalline silicon the a-Si has been used as a photovoltaic solar cell material for devices which require very little power such as pocket calculators and toys.Since the thin layer of a-Si can be deposited onto various types of substrate. This enables the form of PV modules made of a-Si having a much greater variety. Furthermore, silicon in its amorphous form does not have the limitations of thickness or mechanical strength as in crystalline form. These special properties facilitate its application in a flexible form. This is very suitable for producing PV modules for building applications. Together with its performance being less moved(p) by the heat built up in the modules, it can be a good candidate for applications in hot climates. The a-Si PV modules area commercially available for installation onto the roofs of buildings every applied onto the finished ro of or integrated into the roof covering. The advantage over traditional PV panels is that they are very low in weight. It is not subject to wind lifting and can be walked on. The comparable disadvantages are increased cost and reduced efficiency.Flexible a-Si PV modules can made as roofing material2.4 other Thin-Film TechnologiesThin-film is the general term for PV cells produced other than those thick layers of crystalline silicon. Amorphous silicon is the earliest exploit thin-film technology. Its development was mainly from the drive to lower production costs by using significantly less rea material and energy input during the manufacturing process. Other new comers comprise Copper Indium Diselenide (CIS), Cadmium Telluride (CdTe) and so on.In 1975, a Copper Indium Diselenide (CIS) cell of 12% efficiency was successfully demonstrated at the USAs Bell Labs and work at the National Renewable Energy Laboratory (NREL) developed the technology under the US division of Energys thin film program during the 1980s, consolidating the technologys promise (Zweibel, 1990, pp.161-180). Due to the collapse of research funding in the US it was almost another 10 years before Siemens Solar Industries (SSI) produced the first commercially CIS modules in late 1990s. A family of similar compounds has also been developed such as CuInSe2, CuGaSe2, CuInS2, Cu2 and so on. the coating of thin film CIS onto substrate was found to be more flexible and easily manipulated (Goetzberger and Hoffmann, 2005, p.65). Therefore CIS is the major material used within this family of compounds.Similar to a-Si, CIS can be coated into many types of substrate. The choices of CIS modules are wider. For example, flexible CIS modules and modules on polymer back sheets can be found on the PV market. However, due to the rapidly evolving technology, the manufacturing process and even the compound used for CIS modules are ever changing. Second generation CIS modules was reported by Palm et al. (2004) and more development is imminent. With the flexibility in manufacturing the modules, CIS can be one of the candidates for building integration.These can further be divided into ordinary Building-Integrated Photovoltaic (BIPV) system and Photovoltaic (PV) systems and the solar cells in the market can be classified into two main categories Crystalline Silicon Cells and Thin-Film Cells. PV cells are generally made either from crystalline silicon, sliced from ingots or castings, from grown ribbons or thin film, deposited in thin layers on a low-cost backing.The performance of a solar cell is measured in terms of its efficiency at round sunlight into electricity. A typical commercial solar cell has an efficiency of 15% about one-sixth of the sunlight striking the cell generates electricity. alter solar cell efficiencies while holding down the cost per cell is an important goal of the PV industry.Cadmium Telluride (CdTe) has a similar long fib in the whole group of thin-film PV modules. D ue to its tolerance to defects and grain boundaries, unsubdivided and easy to handle deposition process is possible for this material (Luther et al. 2003, p.70). Technology wise this type of material should have been booming. The major hurdle now is the market acceptance since both Cadmium and Telluride are toxic materials although CdTe itself is stable and harmless to the environment. Furthermore, different countries have different regulations regarding Cadmium containing materials (Deb, 2002). This uncertainty talent increase the risk factor in investing production plant for CdTe and BP Solar was reported to have closed their CdTe plant (Luther et al. 2003, p.72).Synergising with the technology furtherance in device handling and manufacturing process in semi-conductor industry, there are emerging technologies for thin film PV cell (Sopori, 2003, p.308). These include crystalline silicon thin film (m-SiTF), micro-crystalline silicon (m-Si) and so on. However, they are still new technology and even not yet commercialized.Due to the longer history of development, crystalline silicon PV modules are still the more common to apply for the building envelope nowadays. But due to the PV modules brittleness, it have to be well protected by the glass layer and backing. It is this intrinsic nature of crystalline silicon that determines the formation and hence limits its applications on buildings. On the other hand, the thin film photovoltaic technology can be applied on many more substrate and the flexible film modules are available for thin film besides glass-glass modules and glass film modules that are common in crystalline silicon technology. The different size, form, material used can apply to the different building design. Hence, the applications of thin film photovoltaic modules are better than the crystalline silicon nowadays.2.5 Electrical Characteristics and PerformancePV modules can perform as the building envelope to keep out the weather and control heat gain. To analysis the electrical performance of a PV module, both the fast power output and the energy yield over the time end under investigation has been considered. Instantaneous power has been normalized to per unit power under Standard Test Condition (STC) for easy comparison between different types of technology. Each PV panel is rated under industrial STC of solar irradiance of 1,000W/m2 with zero incline of incidence, solar spectrum of 1.5 air mass and 25 cell temperature. Electrical characteristics from manufacturers include maximum rated power, open circuit voltage, short circuit current, maximum power voltage, maximum power current and the temperature coefficients .Also, the energy yield has been normalized in a similar manner. The methodology of evaluation of performance has been based on the Standard IEC 61724 (1998).2.6 Photovoltaic SimulationIn the photovoltaic system simulation, the prediction of the PV module performance is the core part of the simulator. Normal ly, the stamp is based on the personal characteristics of the photo electric effect at the semi-conductor. The simulation is calculated the photo-current generated by a certain amount of the irradiance at the surface of the semi-conductor at specific physical conditions. Nowadays, the most of the commercial photovoltaic system simulation programs is the profane series of data being simulated such as RETSCREEN, PVPSYST, PVSOL, PV-Design Pro, Hybird2 kor and so on.2.6.1 RETSCREENThe RETScreen software package system is a program developed by Natural Resources Canada for evaluating both financial and environmental costs and benefits for many different renewable energy technologies. RETScreen has a specific Photovoltaic Project Model that can model PV array performance for many locations around the worldncludes a climatical database including average measurements for 4700 ground stations, compiled from over 20 different sources, and covering the flow 1961-1990. These data are p resented as a queer coherent database, and present numerous parameters including Irradiation, air temperature and wind velocities.2.6.2 PVSYSTPVsyst software has been developed at the University of geneva in Switzwerland. This is an excellent package for design and analysis of a solar photovoltaic system. It is widely used due to the many parameters available for the user to modify. This software is oriented towards architects, engineers, researchers and holds very helpful tools for education. Both stand-alone and grid-connected PV as well as solar water pumping system could be intentional by using PVsyst.2.6.3 PVSOLThe PVSol program is photovoltaic system analysis software developed by ValentinEnergy Software in Germany with an English terminology version distributed by the SolarDesign Company based in the UK. The first version of PVSol was released in 1998.2.6.4 PV-Design ProPVDesignPro software is a commercially available software model developed by the Maui Solar Energy Softw are Corporation (MSESC) and SNL for photovoltaic systems manikin. The software incorporates algorithms from both of SNLs PV array and inverter performance models as well as SNLs database of PV module and inverter parameters. NIST uses a custom version of PVDesignPro for comparing different PV technologies and predicting PV module performance for BIPV applications. The program uses an hourly time-step for modeling system performance.2.6.5 Hybird2Hybrid2 is described as a probabilistic time series computer model for evaluating the performance and economics of hybrid electricity generating systems. It was developed by the Renewable Energy Research Laboratory (RERL) at the University of mum Amherst with support from NREL. This program is an engineering design model for hybrid systems consisting of PV, wind, generators and battery storage for both on-grid and off-grid systems2.5.6 HOMERHOMER is a hybrid system model developed at NREL in 1993 for both on-grid and offgrid systems. A uniq ue capability that HOMER offers is the ability to find the optimal configuration based on price estimates as well as perform sensibility analysis to help understand tradeoffs between different technologies and economic considerations. The software has the ability to compare multiple system configurations as well as different battery types. HOMER uses the KiBaM code for battery life modeling as described below in Section 4.2.1. The model can incorporate the following componen