Photovoltaics

Photovoltaic \'tree\' in Styria, Austria

Renewable energy
Biofuels Biomass Geothermal Hydro power Solar power Tidal power Wave power Wind power

Photovoltaics, or PV for short, is a technology that converts light directly into electricity. Photovoltaics is also the field of study relating to this technology and there are many research institutes devoted to work on photovoltaics.School of Photovoltaic and Renewable Energy EngineeringArizona State University Photovoltaic Testing Laboratory Due to the growing need for solar energy, the manufacture of solar cells and solar photovoltaic array has expanded dramatically in recent years.German PV marketBP Solar to Expand Its Solar Cell Plants in Spain and IndiaLarge-Scale, Cheap Solar Electricity Photovoltaic production has been doubling every two years, increasing by an average of 48 percent each year since 2002, making it the world’s fastest-growing energy technology. At the end of 2007, according to preliminary data, cumulative global production was 12,400 megawatts.Earth Policy Institute (2007). Solar Cell Production Jumps 50 Percent in 2007 Roughly 90% of this generating capacity consists of grid-tied electrical systems. Such installations may be ground-mounted (and sometimes integrated with farming and grazing)GE Invests, Delivers One of World\'s Largest Solar Power Plants or building integrated.Building integrated photovoltaics Financial incentives, such as preferential feed-in tariffs for solar-generated electricity and net metering, have supported solar PV installations in many countries including Germany, Japan, and the United States.German PV market

Solar photovoltaics provided 0.04% of the world\'s Total Primary Energy Supply (TPES) for the year 2004, at a rate of growth to reach 0.40% by 2010. OECD, IEA (2007-Jan). "Renewables In Global Energy Supply - An IEA Fact Sheet". IEA. Retrieved on 2007-12-29. 

Contents 1 Current development 2 Worldwide installed photovoltaic totals 3 Applications of PV 3.1 PV power stations 3.2 PV in buildings 3.3 PV in transport 3.4 PV in standalone devices 4 Economics of PV 4.1 Power costs 4.2 Grid parity 4.3 Financial incentives 5 Environmental impacts 5.1 Greenhouse gases 5.2 Cadmium 5.3 Energy Payback Time and Energy Returned on Energy Invested 6 Advantages 7 Disadvantages 8 Photovoltaics companies 9 Photovoltaic Industry Associations 10 Photovoltaics research institutes 11 See also 12 References 13 External links

Current development

Photovoltaic cells produce electricity directly from sunlight

Average solar irradiance, watts per square metre. Note that this is for a horizontal surface, whereas solar panels are normally propped up at an angle and receive more energy per unit area. The small black dots show the area of solar panels needed to generate all of the worlds energy using 8% eff. PVs.

Map of solar electricity potential in Europe

Photovoltaics is best known as a method for generating solar power by using solar cells packaged in photovoltaic modules, often electrically connected in multiples as solar photovoltaic arrays to convert energy from the sun into electricity. To explain the photovoltaic solar panel more simply, photons from sunlight knock electrons into a higher state of energy, creating electricity.

Photovoltaics can refer to the field of study relating to this technology, and the term photovoltaic denotes the unbiased operating mode of a photodiode in which current through the device is entirely due to the transduced light energy. Virtually all photovoltaic devices are some type of photodiode.^{[citation needed]}

Solar cells produce direct current electricity from light, which can be used to power equipment or to recharge a battery. The first practical application of photovoltaics was to power orbiting satellites and other spacecraft and pocket calculators, but today the majority of photovoltaic modules are used for grid connected power generation. In this case an inverter is required to convert the DC to AC. There is a smaller market for off grid power for remote dwellings, roadside emergency telephones, remote sensing, and cathodic protection of pipelines.

Cells require protection from the environment and are packaged usually behind a glass sheet. When more power is required than a single cell can deliver, cells are electrically connected together to form photovoltaic modules, or solar panels. A single module is enough to power an emergency telephone, but for a house or a power plant the modules must be arranged in arrays. Although the selling price of modules is still too high to compete with grid electricity in most places, significant financial incentives in Japan and then Germany triggered a huge growth in demand, followed quickly by production. Although module prices rose and plateauedSolar Module Price Environment, it is expected that costs and prices will fall to \'grid parity\' in many places around 2010.

Many corporations and institutions are currently developing ways to increase the practicality of solar power. While private companies conduct much of the research and development on solar energy, colleges and universities and institutes also work on solar-powered devices. Most research is being carried out in Germany, Japan, USA and Australia. Solar power has received less research funding than other sources, but is seen as the most likely largest source of electricity in 15 years in the United States. Solar Power Wins Enthusiasts but Not Money Registration required. "The trade association for the nuclear power industry recently asked 1,000 Americans what energy source they thought would be used most for generating electricity in 15 years. The top choice? Not nuclear plants, or coal or natural gas. The winner was the sun, cited by 27 percent of those polled." "Propelled by government incentives in Germany and Japan, as well as a growing number of American states, sales of solar panels made of silicon that convert sunlight directly into electricity, known as photovoltaic cells, have taken off, lowering manufacturing costs and leading to product refinements." "Yet research on solar power and methods for storing intermittent energy has long received less spending, both in the United States and in other industrialized countries, than energy options with more political support."

The most important issue with solar panels is capital cost (installation and materials). Because of much increased demand, the price of silicon has risen and shortages occurred in 2005 and 2006. Newer alternatives to standard crystalline silicon modules including casting wafers instead of sawing A Better Way to Make Solar Power, thin film (CdTeCompany Information Overview, CIGSThe technology at a glance, amorphous SiConverting sunlight to electricity, microcrystalline Si), concentrator modules, \'Sliver\' cells, and continuous printing processes. Due to economies of scale solar panels get less costly as people use and buy more — as manufacturers increase production to meet demand, the cost and price is expected to drop in the years to come. As of early 2006, the average cost per installed watt for a residential sized system was about USD 6.50 to USD 7.50, including panels, inverters, mounts, and electrical items.Solar Photovoltaic Panels In 2007 investors began offering free solar panel installation in return for a 25 year contract to purchase electricity at a fixed price, normally set at or below current electric rates.[1]MMA Renewable Ventures Solar Energy ProgramU.S. Retailers Save with Solar PV & Energy Efficiency

A new photovoltaic "thin film" technology being pioneered by Californian company Nanosolar allows cells to be mass produced by printing them on to aluminium film at a fraction of the cost of existing techniques. At December 2007 the company claims it can achieve costs of USD $0.99 a watt which would be comparable to coal produced electricity. Vidal, John. "Solar energy \'revolution\' brings green power closer", The Guardian, December 29 2007. Retrieved on 2007-12-31. 

Commercial production of roll-to-roll thin film technology, commenced on 2007 in Cardiff Wales, by a company called "G24 Innovations", owned in part by the Ecole Polytechnique Fédérale de Lausanne (EPFL), which is the source for some of its technology (Dye-sensitized solar cells). It claims that its products "...incorporate raw materials that are both inexpensive and effectively limitless..." and that it has a current production capability of 30MW.

A less common form of the technologies is thermophotovoltaics, in which the thermal radiation from some hot body other than the sun is utilized. Photovoltaic devices are also used to produce electricity in optical wireless power transmission.

Worldwide installed photovoltaic totals

See also: Deployment of solar power to energy grids

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World solar photovoltaic (PV) market installations reached a record high of 1.7 gigawatts peak (GWp) in 2006.MarketBuzz 2007: Annual World Solar Photovoltaic Industry Report.

The three leading countries (Germany, Japan and the USA) represent nearly 89% of the total worldwide PV installed capacity. On Wed 01 Aug 2007, word was published of construction of a production facility in China, which is projected to be one of the largest wafer factories in the world, with an annual capacity of around 1,500MW.Geoff Nairn (2007-08-01 Wed 18:14 CEST). "Shiny prospects for solar equipment makers". EngagingChina. Retrieved on 2008-02-14. 

Germany was the fastest growing major PV market in the world during 2005 and 2006. In 2006, nearly 1GWp of PV was installed. The German PV industry generates over 10,000 jobs in production, distribution and installation. By the end of 2006, nearly 88% of all solar PV installations in the EU were in grid-tied applications in Germany. The balance is off-grid (or stand alone) systems.German PV market Photovoltaic power capacity is measured as maximum power output under standardized test conditions (STC) in "Wp" (Watts peak).Antonio Luque and Steven Hegedus (2003). Handbook of Photovoltaic Science and Engineering. John Wiley and Sons. ISBN 0471491969.  The actual power output at a particular point in time may be less than or greater than this standardized, or "rated," value, depending on geographical location, time of day, weather conditions, and other factors.The PVWatts Solar Calculator Solar photovoltaic array capacity factors are typically under 25%, which is lower than many other industrial sources of electricity.UtiliPoint International, Inc. \'Issue alert - What is a megawatt? Therefore the 2006 installed base peak output would have provided an average output of 1.2 GW (assuming 20% × 5,862 MWp). This represented 0.06 percent of global demand at the time.Total electric power consumption

Produced, Installed & Total Photovoltaic Peak Power Capacity (MWp) as of the end of 2006

#	Country or Region Report Nat. Int.	Produced Cells	Off-grid Δ	On-grid Δ	Installed 2006	Off-grid Σ	On-grid Σ	Total 2006	Wp/capita Total	Mod. Price USD/Wp	kW·h/kWp·yr Insolation
	World	1,866.1	97.14	1,452	1,549	712.3	5,150	5,862	0.879	3.14-14.0	0800-2902
	European Union	653.7	16.57	1,032	1,049	111.9	3,108	3,220	6.533	3.8-10.1	0800-2200
1	Germany Dr. Wissing, Lothar; Jülich, Forschungszentrum & Jülich, Projektträger (2007-May). "National Survey Report of PV Power Applications in Germany 2006 - Version 2". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20. Bründlinger, Roland; Cowley, Paul & Watt, Greg et al. (See:Table 11 – IEA PVPS Task 1 national report authors) (2007-Aug). "Trends In Photovoltaic Applications - Survey report of selected IEA countries between 1992 and 2006". IEA - PVPS Programme - IEA PVPS T1-16:2007. Retrieved on 2007-11-05.	514.0	3	950	953	32	2,831	2,863	34.781	5-6.6	1000-1300Sherwood, Larry; Les Nelson, Fred Morse, Jeff Wolfe, Chris O’Brien (2006). "US Solar Industry - Year In Review - 2006". Solar Energy Industries Association (SEIA) & The Prometheus Institute for Sustainable Development. Retrieved on 2007-10-20.
2	Japan Ikki, Osamu; Matsubara, Koji (2007-May 25). "National Survey Report of PV Power Applications in Japan 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	919.8	1.531	285.1	286.6	88.59	1,620	1,709	13.374	3.7	1200-1600
3	United States Pedigo, Susannah; Maycock, Paul D. & Bower, Ward (2007-Aug 30). "National Survey Report of PV Power Applications in The United States Of America 2006 - Version 14". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	201.6	37	108	145	270	354	624	2.058	3.75	0900-2150
4	Spain ?	75.3	9.1	51.4	60.5	17.8	100.4	118.2	2.620	3.8-5.6	1600-2200
5	China ?		15		15	73		73	0.055		1300-2300
6	Australia Watt, Muriel (2007-May). "National Survey Report of PV Power Applications in Australia 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-16.	36.0	7.576	2.145	9.721	60.536	9.765	70.301	3.327	5.6-6.8	1450-2902Blakers, Andrew W. (2000). "Solar and Wind Electricity in Australia". Australian Journal of Environmental Management, Vol 7, pp 223-236, 2000. Retrieved on 2008-02-14.
7	Netherlands Swens, Job (2007-May). "National Survey Report of PV Power Applications in The Netherlands 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	18.0	0.278	1.243	1.521	5.713	46.992	52.705	3.217	4.1-5.6	1000-1200
8	Italy Guastella, Salvatore; Castello, Salvatore & Anna De Lillo (2007-May). "National Survey Report of PV Power Applications in Italy 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	11.0	0.5	12	12.5	12.8	37.2	50	0.846	4-4.5	1400-2200
9	France ?	33.5	1.478	9.412	10.89	21.554	22.379	43.933	0.685	4-6.4	1100-2000
10	South Korea Yoon, Kyung-Hoon; Kim, Donghwan & Yoon, Kyung Shick (2007-May). "National Survey Report of PV Power Applications in Korea 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	18.0	0.28	20.929	21.209	5.943	28.79	34.733	0.716	4.4-4.8	1500-1600
11	Thailand ?		6		6	30		30	0.477	3.14	2200-2400
12	Switzerland Hüsser, Pius; Hostettler, Thomas (2007-May). "National Survey Report on PV Power Applications in Switzerland 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-12-11.		0.15	2.5	2.65	3.4	26.3	29.7	3.955	4-4.2	1200-2000
13	Austria ?		0.274	1.29	1.564	3.169	22.416	25.585	3.076	4.5-5.4	1200-2000
14	Luxembourg ?EurObserv\'ER, (Includes Some Discredited/Preliminary Sources) (2007-April). "EurObserv’ER - Photovoltaic Energy Barometer" (PDF). Systèmes Solaires - Le Journal des Énergies Renouvelables n° 178: pp. 49–70. Retrieved on 2007-09-07.			0.042	0.042		23.603	23.603	50.542		1100-1200
15	Canada Ayoub, Josef; Martel, Sylvain & Dr. Dignard-Bailey, Lisa (2007-May). "National Survey Report of PV Power Applications in Canada 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-16.		3.354	0.384	3.738	18.976	1.508	20.484	0.620	4.7	0900-1750
16	Mexico ?		0.938	0.116	1.054	19.592	0.155	19.747	0.185	6.8-8.1	1700-2600
17	United Kingdom ?	1.9	0.158	3.007	3.165	1.082	12.96	14.042	0.232	4.6-7.2	0900-1300
18	India ?		6		6	12		12	0.010		1700-2500
19	Norway Bugge, Lars; Salvesen, Fritjof (2007-May 30). "National Survey Report of PV Power Applications in Norway 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.	37.0	0.35	0.053	0.403	7.54	0.128	7.668	1.624	14.0	0800-0950
20	Greece ?		1.049	0.201	1.25	5.081	1.613	6.694	0.601		1500-1900
21	Sweden Malm, Ulf; Stolt, Lars (2007-May). "National Survey Report of PV Power Applications in Sweden 2006". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.		0.302	0.301	0.613	4.285	0.555	4.84	0.529	4.1-8.8	0900-1050
22	Belgium ?			2.103	2.103	0.053	4.108	4.161	0.398		1000-1200
23	Finland ?			0.064	0.064	3.779	0.287	4.066	0.768		0800-1050
24	Bangladesh ?		1.134		1.134	3.6		3.6	0.023		1900-2100
25	Sri Lanka ?		0.65		0.65	3.6		3.6	0.187		2200-2400
26	Portugal ?		0.25	0.227	0.477	2.691	0.775	3.466	0.326		1600-2200
27	Denmark Ahm, Peter (2007-May). "National Survey Report of PV Power Applications in Denmark 2006 - Version 04". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.		0.04	0.21	0.25	0.335	2.565	2.9	0.531	6.7-10.1	0900-1100
28	Nepal ?		0.333		0.333	2.333		2.333	0.083		1900-2200
29	Israel Dr. Siderer, Yona; Dann, Roxana (2007-May). "National Survey Report of PV Power Applications in Israel 2006 - Version 14". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20.		0.275		0.275	1.294	0.025	1.319	0.183	5.4	2200-2400
30	Cyprus ?		0.08	0.44	0.52	0.45	0.526	0.976	1.142		1900-2200
31	Czech Republic ?			0.241	0.241	0.15	0.621	0.771	0.075		1100-1300
32	Malaysia Gulabrai, Lalchand; Ruoss, Daniel; Chen, Wei-nee; Ir Ahmad Hadri Haris (2007-April). "National Survey Report of PV Power Applications in Malaysia 2006 - Version 14". IEA - PVPS Programme - NSRs for 2006. Retrieved on 2007-10-20. ?			0.00452	0.00452		0.486	0.486	0.018	5.94	1950-2250
33	Poland ?		0.027	0.087	0.114	0.319	0.112	0.431	0.011		1100-1300
34	Slovenia ?			0.183	0.183	0.098	0.265	0.363	0.180		1300-1500
35	Ireland ?					0.3		0.3	0.070		1000-1200
36	Hungary ?					0.09	0.065	0.155	0.015		1300-1500
37	Slovakia ?		0.004		0.004	0.064		0.064	0.012		1200-1400
38	Malta ?			0.033	0.033		0.048	0.048	0.118		2100-2200
39	Lithuania ?		0.023		0.023	0.04		0.04	0.012		1100-1300
40	Estonia ?		0.005		0.005	0.008		0.008	0.006		1100-1200
41	Latvia ?		0.001		0.001	0.006		0.006	0.003		1100-1300
#	Country or Region Report Nat. Int.	Produced Cells	Off-grid Δ	On-grid Δ	Installed 2006	Off-grid Σ	On-grid Σ	Total 2006	Wp/capita Total	Mod. Price USD/Wp	kW·h/kWp·yr Insolation

Notes: While National Report(s) may be cited as source(s) within an International Report, any contradictions in data are resolved by using only the most recent report\'s data. Exchange rates represent the 2006 annual average of daily rates (OECD Main Economic Indicators June 2007)
Module Price:Lowest: 2.5 EUR/Wp (2.83 USD/WpFRB: G.5A Release-- Foreign Exchange Rates, Release Dates) in Germany 2003.Highest: 90 NOK/Wp (14.0 USD/Wp) in Norway 2006
Partly Defunct Sources: PV Power (2007-June), , EurObserv\'ER, (Includes Some Discredited/Preliminary Sources) (2007-April). "EurObserv’ER - Photovoltaic Energy Barometer" (ASP). Systèmes Solaires - Le Journal des Énergies Renouvelables n° 178: pp. 49–70. Retrieved on 2007-09-07. , IEA PVPS website.

Applications of PV

11 MW Serpa solar power plant in Portugal

Main article: Photovoltaic system

PV power stations

Main article: Photovoltaic power stations

The Table below provides details of some of the largest photovoltaic plants in the world. As shown, Germany has a 10 MW photovoltaic system in Pocking, and a 12 MW plant in Arnstein, with a 40 MW power station planned for Muldentalkreis. Portugal has an 11 MW plant in Serpa and a 62 MW power station is planned for Moura. A 20 MW power plant is also planned for Beneixama, Spain. The photovoltaic power station proposed for Australia will use heliostat concentrator technology and will not come into service until 2010. It is expected to have a capacity of 154 MW when it is completed in 2013.Solar Systems Facts Sheet

World\'s largest PV power plantsWorld\'s largest photovoltaic power plants

DC Peak Power	Location	Description	GW·h/year
154 MW**	Mildura/Swan Hill, Australia154 MW Victoria (Australia) Project	Heliostat Concentrator Photovoltaic technology (see Solar power station in Victoria)	270
62 MW*	Moura, PortugalPortugal plans biggest solar station THE WORLD\'S LARGEST PHOTOVOLTAIC POWER PLANT IN MOURA, PORTUGAL	BP, Yingli Green Energy (see Girassol solar power plant)	88
40 MW*	Muldentalkreis, GermanyLarge photovoltaic plant in Muldentalkreis World’s largest solar power plant being built in eastern Germany	550,000 thin-film modules (First Solar) (see Waldpolenz Solar Park)	40
20 MW	Beneixama, SpainLarge photovoltaic plant in BeneixamaPhotovoltaic plant in BeneixamaImage of world\'s largest solar plant	Tenesol, Aleo and Solon solar modules with Q-Cells cells (see Beneixama photovoltaic power plant	30
14 MW	Nellis AFB, NevadaNellis activates Nations largest PV Array	PowerLight PowerTracker system (see Nellis Solar Power Plant)	30
13.8 MW	Salamanca, SpainLarge photovoltaic power plants	(see Planta Solar de Salamanca)
12.7 MW	Murcia, Spain	(see Lobosillo Solar Park)
12 MW	Arnstein, GermanyThe largest photovoltaic plant	1464 SOLON mover (see Erlasee Solar Park)	14
11 MW	Serpa, PortugalGE, SunPower, Catavento team on plant. BusinessWeek (2007-03-28). Retrieved on 2007-03-29.	52,000 solar modules (see Serpa solar power plant)	n.a.
10 MW	Pocking, Germany	57,912 solar modules (see Pocking Solar Park)	11.5
9.5 MW	Milagro, Spain	(see Monte Alto photovoltaic power plant)	14

* Under construction; ** Proposed

PV in buildings

Main article: Building-integrated photovoltaic

Photovoltaic solar panels on a house roof.

Building-integrated photovoltaics (BIPV) are increasingly incorporated into new domestic and industrial buildings as a principal or ancillary source of electrical power,buildingsolar.com: Building Integrated Photovoltaics, Wisconsin Public Service Corporation, accessed: 2007-03-23. and are one of the fastest growing segments of the photovoltaic industry.Terrasolar, accessed: 2007-03-23. Typically, an array is incorporated into the roof or walls of a building, and roof tiles with integrated PV cells can now be purchased. Arrays can also be retrofitted into existing buildings; in this case they are usually fitted on top of the existing roof structure. Alternatively, an array can be located separately from the building but connected by cable to supply power for the building.

Where a building is at a considerable distance from the public electricity supply (or grid) - in remote or mountainous areas – PV may be the preferred possibility for generating electricity, or PV may be used together with wind, diesel generators and/or hydroelectric power. In such off-grid circumstances batteries are usually used to store the electric power.

PV in transport

Main article: Photovoltaics in transport

PV has traditionally been used for auxiliary power in space. PV is rarely used to provide motive power in transport applications, but is being used increasingly to provide auxiliary power in boats and cars. Recent advances in solar cell technology, however, have shown the cell\'s ability to administer significant hydrogen production, making it one of the top prospects for alternative energy for automobiles.

PV in standalone devices

Solar powered parking meter.

PV has been used for many years to power calculators and novelty devices. Improvements in integrated circuits and low power LCD displays make it possible to power a calculator for several years between battery changes, making solar calculators less common. In contrast, solar powered remote fixed devices have seen increasing use recently, due to increasing cost of labour for connection of mains electricity or a regular maintenance programme. In particular, parking meters http://www.roadtraffic-technology.com/contractors/parking/parkeon/ Parkeon parking meters, emergency telephones Security Products, Dec 2006, p42, and temporary traffic signs.

Economics of PV

This section may contain original research or unverified claims. Please improve the article by adding references. See the talk page for details. (September 2007)

See also: Renewable energy commercialization

US average daily solar energy insolation received by a latitude tilt photovoltaic cell.

Power costs

The PV industry is beginning to adopt levelized cost of energy (LCOE) as the unit of cost. The results of a sample calculation can be found on pp. 52, 53 of the 2007 DOE report describing the plans for solar power 2007-2011 [2]. For a 10 MW plant in Phoenix, AZ, the LCOE is estimated at $0.15 to 0.22/kWh.

The table below is a pure mathematical calculation. It illustrates the calculated total cost in US cents per kilowatt-hour of electricity generated by a photovoltaic system as function of the investment cost and the efficiency, assuming some accounting parameters such as cost of capital and depreciation period. The row headings on the left show the total cost, per peak kilowatt (kWp), of a photovoltaic installation. The column headings across the top refer to the annual energy output in kilowatt-hours expected from each installed peak kilowatt. This varies by geographic region because the average insolation depends on the average cloudiness and the thickness of atmosphere traversed by the sunlight. It also depends on the path of the sun relative to the panel and the horizon.

Panels can be mounted at an angle based on latitude, which can add to total energy outputEERE\'s Consumer Guide: Siting Your Small Solar Electric System. Solar tracking can also be utilized to access even more perpendicular sunlight, thereby raising the total energy output. The calculated values in the table reflect the total cost in cents per kilowatt-hour produced. They assume a 10% total capital cost (for instance 4% interest rate, 1% operating and maintenance cost, and depreciation of the capital outlay over 20 years).

Table showing average cost in cents/kWh over 20 years for solar power panels

	Insolation
Cost	2400 kWh/kWp•y	2200 kWh/kWp•y	2000 kWh/kWp•y	1800 kWh/kWp•y	1600 kWh/kWp•y	1400 kWh/kWp•y	1200 kWh/kWp•y	1000 kWh/kWp•y	800 kWh/kWp•y
200 $/kWp	0.8	0.9	1.0	1.1	1.3	1.4	1.7	2.0	2.5
600 $/kWp	2.5	2.7	3.0	3.3	3.8	4.3	5.0	6.0	7.5
1000 $/kWp	4.2	4.5	5.0	5.6	6.3	7.1	8.3	10.0	12.5
1400 $/kWp	5.8	6.4	7.0	7.8	8.8	10.0	11.7	14.0	17.5
1800 $/kWp	7.5	8.2	9.0	10.0	11.3	12.9	15.0	18.0	22.5
2200 $/kWp	9.2	10.0	11.0	12.2	13.8	15.7	18.3	22.0	27.5
2600 $/kWp	10.8	11.8	13.0	14.4	16.3	18.6	21.7	26.0	32.5
3000 $/kWp	12.5