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{{Short description|Conversion of energy from sunlight into electricity}}{{about|the conversion of energy from sunlight into electricity|a broader range of human uses for sunlight|Solar energy|the unit of light from stars and galaxies|Solar luminosity}}{{Other uses|Solar Power (disambiguation){{!}}Solar Power}}{{pp-move-indef}}{{Use dmy dates|date=January 2017}}{{Multiple image }}Solar power, also known as solar electricity, is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Solar panels use the photovoltaic effect to convert light into an electric current.WEB, Energy Sources: Solar,weblink live,weblink" title="web.archive.org/web/20110414081047weblink">weblink 14 April 2011, 19 April 2011, Department of Energy, dmy-all, Concentrated solar power systems use lenses or mirrors and solar tracking systems to focus a large area of sunlight to a hot spot, often to drive a steam turbine.Photovoltaics (PV) were initially solely used as a source of electricity for small and medium-sized applications, from the calculator powered by a single solar cell to remote homes powered by an off-grid rooftop PV system. Commercial concentrated solar power plants were first developed in the 1980s. Since then, as the cost of solar panels has fallen, grid-connected solar PV systems' capacity and production has doubled about every three years. Three-quarters of new generation capacity is solar,WEB, Gabbatiss, Josh, 2024-01-12, Analysis: World will add enough renewables in five years to power US and Canada,weblink 2024-02-11, Carbon Brief, en, with both millions of rooftop installations and gigawatt-scale photovoltaic power stations continuing to be built.In 2023, solar power systems generated 5% of the world's electricity,WEB, Executive summary – Renewables 2023 – Analysis,weblink 2024-01-16, IEA, en-GB, compared to 1% in 2015, when the Paris Agreement to limit climate change was signed.WEB, 2022-03-29, Global Electricity Review 2022,weblink 2022-04-03, Ember, en-US, Along with onshore wind, in most countries, the cheapest levelised cost of electricity for new installations is utility-scale solar.WEB, 2023 Levelized Cost Of Energy+,weblink 2023-06-14, Lazard, en, WEB, June 2023, Executive summary – Renewable Energy Market Update – Analysis,weblink 2023-06-14, IEA, en-GB, Almost half the solar power installed in 2022 was rooftop.WEB, Norman, Will, 2023-06-13, Through the roof: 49.5% of world's PV additions were rooftop in 2022 – SolarPower Europe,weblink 2023-06-14, PV Tech, en-US, Much more low-carbon power is needed for electrification and to limit climate change. The International Energy Agency said in 2022 that more effort was needed for grid integration and the mitigation of policy, regulation and financing challenges.WEB, Solar PV – Analysis,weblink 2022-11-10, IEA, en-GB, {{TOC limit|3}}

Potential

{{Sustainable energy}}Geography affects solar energy potential because different locations receive different amounts of solar radiation. In particular, with some variations, areas that are closer to the equator generally receive higher amounts of solar radiation. However, solar panels that can follow the position of the Sun can significantly increase the solar energy potential in areas that are farther from the equator.BOOK, World energy assessment: energy and the challenge of sustainability, 2000, United Nations Development Programme, 978-92-1-126126-4, Goldemberg, José, 1. print, New York, New York, en-us, UNDP, Daytime cloud cover can reduce the light available for solar cells. Land availability also has a large effect on the available solar energy.

Technologies

Solar power plants use one of two technologies:

• Photovoltaic (PV) systems use solar panels, either on rooftops or in ground-mounted solar farms, converting sunlight directly into electric power.
• Concentrated solar power (CSP) systems use mirrors or lenses to concentrate sunlight to extreme heat to make steam, which is converted into electricity by a turbine.

Photovoltaic cells

File:PV-system-schematics-residential-Eng.png|thumb|upright=1.4|Schematics of a grid-connected residential 978-0-470-44633-1}}, Section10.2.A solar cell, or photovoltaic cell, is a device that converts light into electric current using the photovoltaic effect. The first solar cell was constructed by Charles Fritts in the 1880s.{{harvnb|Perlin|1999|p=147}}. The German industrialist Ernst Werner von Siemens was among those who recognized the importance of this discovery.{{harvnb|Perlin|1999|pp=18-20}}. In 1931, the German engineer Bruno Lange developed a photo cell using silver selenide in place of copper oxide,JOURNAL,weblink 41, Magic Plates, Tap Sun For Power, Popular Science, June 1931, 19 April 2011, Corporation, Bonnier, although the prototype selenium cells converted less than 1% of incident light into electricity. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the silicon solar cell in 1954.{{harvnb|Perlin|1999|p=29}}. These early solar cells cost US$286/watt and reached efficiencies of 4.5–6%.{{harvnb|Perlin|1999|pp=29-30,38}}. In 1957, Mohamed M. Atalla developed the process of silicon surface passivation by thermal oxidation at Bell Labs.BOOK, Black, Lachlan E., New Perspectives on Surface Passivation: Understanding the Si-Al2O3 Interface, 2016, Springer, 9783319325217,weblink 13, BOOK, Lojek, Bo, History of Semiconductor Engineering,weblink limited, 2007, Springer Science & Business Media, 9783540342588, 120& 321–323, The surface passivation process has since been critical to solar cell efficiency.BOOK, Black, Lachlan E., New Perspectives on Surface Passivation: Understanding the Si-Al2O3 Interface, 2016, Springer, 9783319325217,weblink {{As of|2022}} over 90% of the market is crystalline silicon. The array of a photovoltaic system, or PV system, produces direct current (DC) power which fluctuates with the sunlight's intensity. For practical use this usually requires conversion to alternating current (AC), through the use of inverters. Multiple solar cells are connected inside panels. Panels are wired together to form arrays, then tied to an inverter, which produces power at the desired voltage, and for AC, the desired frequency/phase.Many residential PV systems are connected to the grid when available, especially in developed countries with large markets.WEB,weblink Trends in Photovoltaic Applications Survey report of selected IEA countries between 1992 and 2009, IEA-PVPS, 8 November 2011, live,weblink" title="web.archive.org/web/20170525165534weblink">weblink 25 May 2017, dmy-all, In these grid-connected PV systems, use of energy storage is optional. In certain applications such as satellites, lighthouses, or in developing countries, batteries or additional power generators are often added as back-ups. Such stand-alone power systems permit operations at night and at other times of limited sunlight.In "vertical agrivoltaics" system, solar cells are oriented vertically on farmland, to allow the land to both grow crops and generate renewable energy. Other configurations include floating solar farms, placing solar canopies over parking lots, and installing solar panels on roofs.NEWS, Budin, Jeremiah, Game-Changing Solar Power Technology to Get First US Installation: Valuable Land is almost Completely Preserved,weblink The Cooldown, 17 January 2024,weblink 17 January 2024,

Thin-film solar

A thin-film solar cell is a second generation solar cell that is made by depositing one or more thin layers, or thin film (TF) of photovoltaic material on a substrate, such as glass, plastic or metal. Thin-film solar cells are commercially used in several technologies, including cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin-film silicon (a-Si, TF-Si).WEB,weblink Thin-Film Solar Panels | American Solar Energy Society,

Perovskite solar cells

{{Excerpt|Perovskite solar cell|paragraphs=1,2|file=yes}}

Concentrated solar power

File:Parabolic trough.svg|thumb|A parabolic collector concentrates sunlight onto a tube in its focal point.]]Concentrated solar power (CSP), also called "concentrated solar thermal", uses lenses or mirrors and tracking systems to concentrate sunlight, then uses the resulting heat to generate electricity from conventional steam-driven turbines.WEB, 2018-06-11, How CSP Works: Tower, Trough, Fresnel or Dish,weblink 2020-03-14, Solarpaces, en-US, A wide range of concentrating technologies exists: among the best known are the parabolic trough, the compact linear Fresnel reflector, the dish Stirling and the solar power tower. Various techniques are used to track the sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight and is then used for power generation or energy storage.Martin and Goswami (2005), p. 45. Thermal storage efficiently allows overnight electricity generation,WEB, Lacey, Stephen, 6 July 2011, Spanish CSP Plant with Storage Produces Electricity for 24 Hours Straight,weblink live,weblink" title="web.archive.org/web/20121012112224weblink">weblink 12 October 2012, dmy-all, thus complementing PV.NEWS, 2022-10-05, More countries are turning to this technology for clean energy. It's coming to Australia, en-AU, ABC News,weblink 2022-11-04, CSP generates a very small share of solar power and in 2022 the IEA said that CSP should be better paid for its storage.WEB, Renewable Electricity – Analysis,weblink 2022-11-04, IEA, en-GB, {{As of|2021}} the levelized cost of electricity from CSP is over twice that of PV.WEB, Renewable Power Generation Costs in 2021,weblink 2022-11-04, irena.org, 13 July 2022, en, However, their very high temperatures may prove useful to help decarbonize industries (perhaps via hydrogen) which need to be hotter than electricity can provide.WEB, Casey, Tina, 2022-09-30, US Energy Dept. Still Holds Torch For Concentrating Solar Power,weblink 2022-11-04, CleanTechnica, en-US,

Hybrid systems

A hybrid system combines solar with energy storage and/or one or more other forms of generation. Hydro,WEB, Garanovic, Amir, 2021-11-10, World's largest hydro-floating solar hybrid comes online in Thailand,weblink 2022-11-07, Offshore Energy, en-US, {{Citation |last1=Ming |first1=Bo |title=Chapter 20 – Operations management of large hydro–PV hybrid power plants: case studies in China |date=2022-01-01 |work=Complementarity of Variable Renewable Energy Sources |pages=439–502 |editor-last=Jurasz |editor-first=Jakub |url=https://www.sciencedirect.com/science/article/pii/B978032385527300008X |access-date=2022-11-07 |publisher=Academic Press |language=en |isbn=978-0-323-85527-3 |last2=Liu |first2=Pan |last3=Guo |first3=Yi |editor2-last=Beluco |editor2-first=Alexandre}} windWEB, World's largest wind-solar hybrid complex goes online in India,weblink 2022-11-07, Renewablesnow.com, en, WEB, Todorović, Igor, 2022-11-04, China completes world's first hybrid offshore wind-solar power plant,weblink 2022-11-07, Balkan Green Energy News, en-US, and batteriesWEB, Which?, Solar panel battery storage,weblink 2022-11-07, Which?, en, are commonly combined with solar. The combined generation may enable the system to vary power output with demand, or at least smooth the solar power fluctuation.JOURNAL, Brumana, Giovanni, Franchini, Giuseppe, Ghirardi, Elisa, Perdichizzi, Antonio, 2022-05-01, Techno-economic optimization of hybrid power generation systems: A renewables community case study,weblink Energy, en, 246, 123427, 10.1016/j.energy.2022.123427, 2022Ene...24623427B, 246695199, 0360-5442, JOURNAL, Wang, Zhenni, Wen, Xin, Tan, Qiaofeng, Fang, Guohua, Lei, Xiaohui, Wang, Hao, Yan, Jinyue, 2021-08-01, Potential assessment of large-scale hydro-photovoltaic-wind hybrid systems on a global scale,weblink Renewable and Sustainable Energy Reviews, en, 146, 111154, 10.1016/j.rser.2021.111154, 235925315, 1364-0321, There is much hydro worldwide, and adding solar panels on or around existing hydro reservoirs is particularly useful, because hydro is usually more flexible than wind and cheaper at scale than batteries,WEB, Todorović, Igor, 2022-07-22, Portugal, Switzerland launch pumped storage hydropower plants of over 2 GW in total,weblink 2022-11-08, Balkan Green Energy News, en-US, and existing power lines can sometimes be used.WEB, Bank (ADB), Asian Development, ADB Partnership Report 2019: Building Strong Partnerships for Shared Progress,weblink 2022-11-07, Asian Development Bank, en-US, WEB, Merlet, Stanislas, Thorud, Bjørn, 2020-11-18, Floating solar power connected to hydropower might be the future for renewable energy,weblink 2022-11-07, sciencenorway.no,

Development and deployment

{{See also|Growth of photovoltaics|Timeline of solar cells|Solar power by country|Concentrated solar power#Deployment around the world}}(File:Share-electricity-solar.svg|thumb|upright=1.35|The share of electricity production from solar, 2022WEB, Share of electricity production from solar,weblink Our World in Data, 15 August 2023, )(File:World solar generation yearly.png |thumb|upright=1.35| Yearly solar generation by continent)(File:2007- New solar installations - annually by country or region.svg |thumb |upright=1.35 |Benefitting from favorable policies and declining costs of modules, photovoltaic solar installation has grown consistently, with China expected to account for 50% of new global solar photovoltaic projects by 2024.WEB, Chart: Solar installations set to break global, US records in 2023,weblink Canary Media,weblink 17 September 2023, 15 September 2023, live, For relevant chart, Canary Media credits: "Source: BloombergNEF, September 2023"WEB, Chase, Jenny, 3Q 2023 Global PV Market Outlook,weblink BloombergNEF,weblink 21 September 2023, 5 September 2023, live, )(File:Installed_solar_PV_capacity_log_graph.svg |thumb |upright=1.35 |The growth of solar PV on a semi-log scale since 1996)(File:Electricity production by source.svg |thumb |upright=1.35 |Electricity production by source)

Early days

The early development of solar technologies starting in the 1860s was driven by an expectation that coal would soon become scarce, such as experiments by Augustin Mouchot.BOOK,weblink Scientific American, 1869-04-10, Munn & Company, 227, en, Charles Fritts installed the world's first rooftop photovoltaic solar array, using 1%-efficient selenium cells, on a New York City roof in 1884.WEB, 31 December 2014, Photovoltaic Dreaming 1875–1905: First Attempts At Commercializing PV,weblink live,weblink 25 May 2017, 30 April 2018, cleantechnica.com, dmy-all, However, development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum.Butti and Perlin (1981), pp. 63, 77, 101. Bell Telephone Laboratories’ 1950s research used silicon wafers with a thin coating of boron. The “Bell Solar Battery” was described as 6% efficient, with a square yard of the panels generating 50 watts.”The Bell Solar Battery” (advertisement). Audio, July 1964, 15. The first satellite with solar panels was launched in 1957.WEB,weblink Vanguard I The World's Oldest Satellite Still in Orbit,weblink" title="web.archive.org/web/20150321054447weblink">weblink 2015-03-21, September 24, 2007, {{PD-notice}}By the 1970s, solar panels were still too expensive for much other than satellites.JOURNAL, Levy, Adam, The dazzling history of solar power, Knowable Magazine, 13 January 2021, 10.1146/knowable-011321-1, 234124275,weblink 25 March 2022, en, free, In 1974 it was estimated that only six private homes in all of North America were entirely heated or cooled by functional solar power systems."The Solar Energy Book—Once More." Mother Earth News 31: 16–17, January 1975. However, the 1973 oil embargo and 1979 energy crisis caused a reorganization of energy policies around the world and brought renewed attention to developing solar technologies.Butti and Perlin (1981), p. 249.Yergin (1991), pp. 634, 653–673.Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan. Other efforts included the formation of research facilities in the United States (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer ISE).WEB, Chronicle of Fraunhofer-Gesellschaft, Fraunhofer-Gesellschaft,weblink 4 November 2007, live,weblink" title="web.archive.org/web/20071212091650weblink">weblink 12 December 2007, dmy-all, Between 1970 and 1983 installations of photovoltaic systems grew rapidly. In the United States, President Jimmy Carter set a target of producing 20% of U.S. energy from solar by the year 2000, but his successor, Ronald Reagan, removed the funding for research into renewables. Falling oil prices in the early 1980s moderated the growth of photovoltaics from 1984 to 1996.

Mid-1990s to 2010

In the mid-1990s development of both, residential and commercial rooftop solar as well as utility-scale photovoltaic power stations began to accelerate again due to supply issues with oil and natural gas, global warming concerns, and the improving economic position of PV relative to other energy technologies.Solar: photovoltaic: Lighting Up The World retrieved 19 May 2009 {{webarchive|url=https://web.archive.org/web/20100813163816weblink|date=13 August 2010}}. In the early 2000s, the adoption of feed-in tariffs—a policy mechanism, that gives renewables priority on the grid and defines a fixed price for the generated electricity—led to a high level of investment security and to a soaring number of PV deployments in Europe.

2010s

For several years, worldwide growth of solar PV was driven by European deployment, but it then shifted to Asia, especially China and Japan, and to a growing number of countries and regions all over the world. The largest manufacturers of solar equipment were based in China.WEB,weblink Top-10 solar cell producers in 2016, Finlay, Colville, PV-Tech, 30 January 2017, live,weblink" title="web.archive.org/web/20170202054912weblink">weblink 2 February 2017, dmy-all, WEB, Ball, Jeffrey, etal, 2017-03-21, The New Solar System – Executive Summary,weblink live,weblink 20 April 2017, 2017-06-27, Stanford University Law School, Steyer-Taylor Center for Energy Policy and Finance, dmy-all, Although concentrated solar power capacity grew more than tenfold, it remained a tiny proportion of the total,WEB,weblink Renewables 2014: Global Status Report, REN21,weblink" title="web.archive.org/web/20140915214208weblink">weblink 15 September 2014, 2014

2020s

Despite the rising cost of materials, such as polysilicon, during the 2021–2022 global energy crisis,WEB, What is the impact of increasing commodity and energy prices on solar PV, wind and biofuels? – Analysis,weblink 2022-04-04, IEA, en-GB, utility scale solar was still the least expensive energy source in many countries due to the rising costs of other energy sources, such as natural gas.WEB, Levelized Cost Of Energy, Levelized Cost Of Storage, and Levelized Cost Of Hydrogen,weblink 2022-04-04, Lazard.com, en, In 2022, global solar generation capacity exceeded 1 TW for the first time.WEB, World Installs a Record 168 GW of Solar Power in 2021, enters Solar Terawatt Age,weblink SolarPower Europe, However, fossil-fuel subsidies have slowed the growth of solar generation capacity.WEB, McDonnell, Tim, 2022-08-29, Soaring fossil fuel subsidies are holding back clean energy,weblink 2022-09-04, Quartz, en,

Current status

About half of installed capacity is utility scale.WEB, Olson, Dana, Bakken, Bent Erik, Utility-scale solar PV: From big to biggest,weblink 2024-01-15, Det Norske Veritas, (File:World PVOUT Solar-resource-map GlobalSolarAtlas World-Bank-Esmap-Solargis.png|thumb|right|upright=1.4|Map of solar resources from World bank)

Forecasts

(File:Reality versus IEA predictions - annual photovoltaic additions 2002-2016.png|thumb|upright=1.4|Actual annual deployments of solar PV vs predictions by the IEA for the period 2002–2016. Predictions have largely and consistently underestimated actual growth.)Most new renewable capacity between 2022 and 2027 is forecast to be solar, surpassing coal as the largest source of installed power capacity.WEB, Renewable electricity – Renewables 2022 – Analysis,weblink 2022-12-12, IEA, en-GB, {{Rp|page=26}} Utility scale is forecast to become the largest source of electricity in all regions except sub-Saharan Africa by 2050.According to a 2021 study, global electricity generation potential of rooftop solar panels is estimated at 27 PWh per year at costs ranging from $40 (Asia) to $240 per MWh (US, Europe). Its practical realization will however depend on the availability and cost of scalable electricity storage solutions.WEB, Cork, University College, Assessing global electricity generation potential from rooftop solar photovoltaics,weblink 2021-10-11, techxplore.com, en,

Photovoltaic power stations

{{See also|List of photovoltaic power stations}}{{Excerpt|Photovoltaic power station}}

Concentrating solar power stations

File:IvanpahRunning.JPG|thumb|upright=1.2|Ivanpah Solar Electric Generating SystemIvanpah Solar Electric Generating SystemFile:Solar Plant kl.jpg|thumb|upright=1.2|Part of the 354 MW Solar Energy Generating Systems (SEGS) parabolic trough solar complex in northern San Bernardino County, CaliforniaSan Bernardino County, CaliforniaCommercial concentrating solar power (CSP) plants, also called "solar thermal power stations", were first developed in the 1980s. The 377 MW Ivanpah Solar Power Facility, located in California's Mojave Desert, is the world's largest solar thermal power plant project. Other large CSP plants include the Solnova Solar Power Station (150 MW), the Andasol solar power station (150 MW), and Extresol Solar Power Station (150 MW), all in Spain. The principal advantage of CSP is the ability to efficiently add thermal storage, allowing the dispatching of electricity over up to a 24-hour period. Since peak electricity demand typically occurs at about 5 pm, many CSP power plants use 3 to 5 hours of thermal storage.What is peak demand? {{webarchive|url=https://web.archive.org/web/20120811072202weblink |date=11 August 2012 }}, Energex.com.au website.

Economics

{{see also|Photovoltaic power station#Economics and finance}}

Cost per watt

{{See also|Cost of electricity by source}}The typical cost factors for solar power include the costs of the modules, the frame to hold them, wiring, inverters, labour cost, any land that might be required, the grid connection, maintenance and the solar insolation that location will receive.Photovoltaic systems use no fuel, and modules typically last 25 to 40 years.JOURNAL, Nian, Victor, Mignacca, Benito, Locatelli, Giorgio, 2022-08-15, Policies toward net-zero: Benchmarking the economic competitiveness of nuclear against wind and solar energy,weblink Applied Energy, en, 320, 119275, 10.1016/j.apenergy.2022.119275, 2022ApEn..32019275N, 249223353, 0306-2619, Thus upfront capital and financing costs make up 80% to 90% of the cost of solar power.{{Rp|page=165}}Some countries are considering price caps,WEB, 2022-09-14, EU expects to raise €140bn from windfall tax on energy firms,weblink 2022-09-15, the Guardian, en, whereas others prefer contracts for difference.WEB, 2022-09-14, The EU's energy windfall tax gives UK ministers a yardstick for their talks,weblink 2022-09-15, The Guardian, en-uk, In many countries, solar power is the lowest cost source of electricity.WEB, 2024-02-09, Why wind and solar are key solutions to combat climate change,weblink 2024-02-11, Ember, en-US, In Saudi Arabia, a power purchase agreement (PPA) was signed in April 2021 for a new solar power plant in Al-Faisaliah. The project has recorded the world's lowest cost for solar PV electricity production of USD 1.04 cents/ kWh.WEB, 8 April 2021, Saudi Arabia signed Power Purchase Agreement for 2,970MW Solar PV Projects,weblink 2022-08-28, saudigulfprojects.com, en,

Installation prices

Expenses of high-power band solar modules has greatly decreased over time. Beginning in 1982, the cost per kW was approximately 27,000 American dollars, and in 2006 the cost dropped to approximately 4,000 American dollars per kW. The PV system in 1992 cost approximately 16,000 American dollars per kW and it dropped to approximately 6,000 American dollars per kW in 2008.JOURNAL, Timilsina, Govinda R., Kurdgelashvili, Lado, Narbel, Patrick A., 2012-01-01, Solar energy: Markets, economics and policies,weblink Renewable and Sustainable Energy Reviews, en, 16, 1, 449–465, 10.1016/j.rser.2011.08.009, 1364-0321, In 2021 in the US, residential solar cost from 2 to 4 dollars/watt (but solar shingles cost much more)WEB, 2021-08-08, Solar Shingles Vs. Solar Panels: Cost, Efficiency & More (2021),weblink 2021-08-25, EcoWatch, en, and utility solar costs were around $1/watt.WEB, 2021-06-18, Solar Farms: What Are They and How Much Do They Cost? {{!, EnergySage|url=https://news.energysage.com/solar-farms-start-one/|access-date=2021-08-25|website=Solar News|language=en-US}}

Productivity by location

{{see also|Solar irradiance}}The productivity of solar power in a region depends on solar irradiance, which varies through the day and year and is influenced by latitude and climate. PV system output power also depends on ambient temperature, wind speed, solar spectrum, the local soiling conditions, and other factors.Onshore wind power tends to be the cheapest source of electricity in Northern Eurasia, Canada, some parts of the United States, and Patagonia in Argentina whereas in other parts of the world mostly solar power (or less often a combination of wind, solar and other low carbon energy) is thought to be best.JOURNAL, Bogdanov, Dmitrii, Ram, Manish, Aghahosseini, Arman, Gulagi, Ashish, Oyewo, Ayobami Solomon, Child, Michael, Caldera, Upeksha, Sadovskaia, Kristina, Farfan, Javier, De Souza Noel Simas Barbosa, Larissa, Fasihi, Mahdi, 2021-07-15, Low-cost renewable electricity as the key driver of the global energy transition towards sustainability, Energy, en, 227, 120467, 10.1016/j.energy.2021.120467, 233706454, 0360-5442, free, 2021Ene...22720467B, {{Rp|page=8}} Modelling by Exeter University suggests that by 2030, solar will be least expensive in all countries except for some in north-eastern Europe.WEB, Is a solar future inevitable?,weblink 2 October 2023, University of Exeter, The locations with highest annual solar irradiance lie in the arid tropics and subtropics. Deserts lying in low latitudes usually have few clouds and can receive sunshine for more than ten hours a day.WEB,weblink Daytime Cloud Fraction Coast lines evident, 2017-08-22, live,weblink" title="web.archive.org/web/20170822174443weblink">weblink 22 August 2017, dmy-all, WEB,weblink Sunshine, 2015-09-06, dead,weblink" title="web.archive.org/web/20150923233148weblink">weblink 23 September 2015, dmy-all, These hot deserts form the Global Sun Belt circling the world. This belt consists of extensive swathes of land in Northern Africa, Southern Africa, Southwest Asia, Middle East, and Australia, as well as the much smaller deserts of North and South America.WEB,weblink Living in the Sun Belt : The Solar Power Potential for the Middle East, 27 July 2016, 2017-08-22, live,weblink" title="web.archive.org/web/20170826121314weblink">weblink 26 August 2017, dmy-all, Thus solar is (or is predicted to become) the cheapest source of energy in all of Central America, Africa, the Middle East, India, South-east Asia, Australia, and several other regions.{{Rp|page=8}}Different measurements of solar irradiance (direct normal irradiance, global horizontal irradiance) are mapped below:File:SolarGIS-Solar-map-North-America-en.png|North AmericaFile:SolarGIS-Solar-map-Latin-America-en.png|South AmericaFile:SolarGIS-Solar-map-Europe-en.png|EuropeFile:SolarGIS-Solar-map-Africa-and-Middle-East-en.png|Africa and Middle EastFile:SolarGIS-Solar-map-South-And-South-East-Asia-en.png|South and South-East AsiaFile:SolarGIS-Solar-map-Australia-en.png|AustraliaFile:SolarGIS-Solar-map-World-map-en.png|World

Self-consumption

In cases of self-consumption of solar energy, the payback time is calculated based on how much electricity is not purchased from the grid.WEB,weblink Money saved by producing electricity from PV and Years for payback, live,weblink 28 December 2014, dmy-all, However, in many cases, the patterns of generation and consumption do not coincide, and some or all of the energy is fed back into the grid. The electricity is sold, and at other times when energy is taken from the grid, electricity is bought. The relative costs and prices obtained affect the economics. In many markets, the price paid for sold PV electricity is significantly lower than the price of bought electricity, which incentivizes self-consumption.REPORT, Trends in Photovoltaic Applications 2014, IEA-PVPS, 2014,weblink live,weblink" title="web.archive.org/web/20170525165925weblink">weblink 25 May 2017, dmy-all, Moreover, separate self-consumption incentives have been used in e.g., Germany and Italy. Grid interaction regulation has also included limitations of grid feed-in in some regions in Germany with high amounts of installed PV capacity.JOURNAL, Stetz, T., Marten, F., Braun, M., 2013, Improved Low Voltage Grid-Integration of Photovoltaic Systems in Germany, IEEE Transactions on Sustainable Energy, 4, 2, 534–542, 2013ITSE....4..534S, 10.1109/TSTE.2012.2198925, 47032066, By increasing self-consumption, the grid feed-in can be limited without curtailment, which wastes electricity.JOURNAL, Salpakari, Jyri, Lund, Peter, Optimal and rule-based control strategies for energy flexibility in buildings with PV, Applied Energy, 2016, 161, 425–436, 10.1016/j.apenergy.2015.10.036, 2016ApEn..161..425S, 59037572,weblink A good match between generation and consumption is key for high self-consumption. The match can be improved with batteries or controllable electricity consumption. However, batteries are expensive, and profitability may require the provision of other services from them besides self-consumption increase,REPORT, Fitzgerald, Garrett, Mandel, James, Morris, Jesse, Touati, Hervé, The Economics of Battery Energy Storage, Rocky Mountain Institute, 2015,weblink dead,weblink" title="web.archive.org/web/20161130145345weblink">weblink 30 November 2016, dmy-all, for example avoiding power outages.WEB, The Value of Electricity Reliability: Evidence from Battery Adoption,weblink 2023-06-14, Resources for the Future, en-US, Hot water storage tanks with electric heating with heat pumps or resistance heaters can provide low-cost storage for self-consumption of solar power. Shiftable loads, such as dishwashers, tumble dryers and washing machines, can provide controllable consumption with only a limited effect on the users, but their effect on self-consumption of solar power may be limited.

Energy pricing, incentives and taxes

The original political purpose of incentive policies for PV was to facilitate an initial small-scale deployment to begin to grow the industry, even where the cost of PV was significantly above grid parity, to allow the industry to achieve the economies of scale necessary to reach grid parity. Since reaching grid parity, some policies are implemented to promote national energy independence,WEB, 2022-04-06, Germany boosts renewables with "biggest energy policy reform in decades",weblink 2022-11-08, Clean Energy Wire, en, high tech job creationWEB, Indigenizing Solar Manufacturing: Charting the Course to a Solar Self-Sufficient India,weblink 2022-11-08, www.saurenergy.com, and reduction of CO2 emissions.Financial incentives for photovoltaics differ across countries, including Australia,WEB, Renewable power incentives,weblink China,China Racing Ahead of America in the Drive to Go Solar. {{webarchive|url=https://web.archive.org/web/20130706133417weblink|date=6 July 2013}}. Germany,WEB, Power & Energy Technology – IHS Technology,weblink live,weblink" title="web.archive.org/web/20100102171748weblink">weblink 2 January 2010, dmy-all, India,WEB, Shankar, Ravi, Jul 20, 2022, What is the solar rooftop subsidy scheme/yojana?,weblink 2022-11-08, The Times of India, en, Japan, and the United States and even across states within the US.

Net metering

File:Feed-in Tariff meter connections.png|thumb|upright=1.5|Net metering, unlike a feed-in tarifffeed-in tariffIn net metering the price of the electricity produced is the same as the price supplied to the consumer, and the consumer is billed on the difference between production and consumption. Net metering can usually be done with no changes to standard electricity meters, which accurately measure power in both directions and automatically report the difference, and because it allows homeowners and businesses to generate electricity at a different time from consumption, effectively using the grid as a giant storage battery. With net metering, deficits are billed each month while surpluses are rolled over to the following month. Best practices call for perpetual roll over of kWh credits.WEB, Net Metering original on 21 October 2012,weblink 2021-10-12, dsireusa.org, en, Excess credits upon termination of service are either lost or paid for at a rate ranging from wholesale to retail rate or above, as can be excess annual credits.WEB, Net Metering and Interconnection – NJ OCE Web Site,weblink live,weblink" title="web.archive.org/web/20120512060609weblink">weblink 12 May 2012, dmy-all,

Community solar

File:Solar farm in Wisconsin 01.jpg|thumb|Community solar farm in the town of Wheatland, WisconsinWEB, Mentzel, Dashal, 2023-10-25, Partnership brings benefits of community solar to Vernon County,weblink 2023-11-22, WEAU, en, ]]A community solar project is a solar power installation that accepts capital from and provides output credit and tax benefits to multiple customers, including individuals, businesses, nonprofits, and other investors. Participants typically invest in or subscribe to a certain kW capacity or kWh generation of remote electrical production.WEB, Community Solar Basics,weblink 2021-09-17, Energy.gov, en,

Taxes

In some countries tariffs (import taxes) are imposed on imported solar panels.WEB, Philipp, Jennifer, 2022-09-07, Solar Power in Africa on the Rise,weblink 2022-09-15, BORGEN, en-US, WEB, Busch, Marc L., 2022-09-02, The mystery of India's new solar tariffs,weblink 2022-09-15, The Hill, en-US,

Grid integration

File:Abengoa Solar (7336087392).jpg|thumb| Construction of the Salt Tanks which provide efficient thermal energy storageWright, matthew; Hearps, Patrick; et al. Australian Sustainable Energy: Zero Carbon Australia Stationary Energy Plan {{webarchive|url=https://web.archive.org/web/20151124173114weblink |date=24 November 2015 }}, Energy Research Institute, University of Melbourne, October 2010, p. 33. Retrieved from BeyondZeroEmissions.org website. so that output can be provided after sunset, and output can be scheduled to meet demand requirements.JOURNAL, Palgrave, Robert, 1 December 2008, Innovation in CSP,weblink dead,weblink" title="web.archive.org/web/20150924090041weblink">weblink 24 September 2015, Renewable Energy Focus, 9, 6, 44–49, Elsevier, 10.1016/S1755-0084(08)70066-8, The 280 MW (Solana Generating Station]] is designed to provide six hours of energy storage. This allows the plant to generate about 38% of its rated capacity over the course of a year.WEB,weblink Solana: 10 Facts You Didn't Know About the Concentrated Solar Power Plant Near Gila Bend, Ray Stern, Phoenix New Times, live,weblink" title="web.archive.org/web/20131011235507weblink">weblink 11 October 2013, dmy-all, 10 October 2013, ){{multiple image }}

Variability

The overwhelming majority of electricity produced worldwide is used immediately because traditional generators can adapt to demand and storage is usually more expensive. Both solar power and wind power are sources of variable renewable power, meaning that all available output must be used locally, carried on transmission lines to be used elsewhere, or stored (e.g., in a battery). Since solar energy is not available at night, storing it so as to have continuous electricity availability is potentially an important issue, particularly in off-grid applications and for future 100% renewable energy scenarios.Carr (1976), p. 85.Solar is intermittent due to the day/night cycles and variable weather conditions. However solar power can be forecast somewhat by time of day, location, and seasons. The challenge of integrating solar power in any given electric utility varies significantly. In places with hot summers and mild winters, solar tends to be well matched to daytime cooling demands.JOURNAL, Ruggles, Tyler H., Caldeira, Ken, 2022-01-01, Wind and solar generation may reduce the inter-annual variability of peak residual load in certain electricity systems, Applied Energy, en, 305, 117773, 10.1016/j.apenergy.2021.117773, 2022ApEn..30517773R, 239113921, 0306-2619, free,

Energy storage

Concentrated solar power plants may use thermal storage to store solar energy, such as in high-temperature molten salts. These salts are an effective storage medium because they are low-cost, have a high specific heat capacity, and can deliver heat at temperatures compatible with conventional power systems. This method of energy storage is used, for example, by the Solar Two power station, allowing it to store 1.44 TJ in its 68 m3 storage tank, enough to provide full output for close to 39 hours, with an efficiency of about 99%.WEB, Advantages of Using Molten Salt, Sandia National Laboratory,weblink 29 September 2007, live,weblink" title="web.archive.org/web/20110605094349weblink">weblink 5 June 2011, dmy-all, In stand alone PV systems, batteries are traditionally used to store excess electricity. With grid-connected photovoltaic power systems, excess electricity can be sent to the electrical grid. Net metering and feed-in tariff programs give these systems a credit for the electricity they produce. This credit offsets electricity provided from the grid when the system cannot meet demand, effectively trading with the grid instead of storing excess electricity.WEB, PV Systems and Net Metering,weblinkweblink" title="web.archive.org/web/20080704062311weblink">weblink 4 July 2008, 31 July 2008, Department of Energy (United States), When wind and solar are a small fraction of the grid power, other generation techniques can adjust their output appropriately, but as these forms of variable power grow, additional balance on the grid is needed. As prices are rapidly declining, PV systems increasingly use rechargeable batteries to store a surplus to be used later at night. Batteries used for grid-storage can stabilize the electrical grid by leveling out peak loads for a few hours. In the future, less expensive batteries could play an important role on the electrical grid, as they can charge during periods when generation exceeds demand and feed their stored energy into the grid when demand is higher than generation.Common battery technologies used in today's home PV systems include nickel-cadmium, lead-acid, nickel metal hydride, and lithium-ion.BOOK, Mohanty, Parimita,weblink Solar Photovoltaic System Applications: A Guidebook for Off-Grid Electrification, Muneer, Tariq, Kolhe, Mohan, 30 October 2015, Springer, 978-3-319-14663-8, 91, 22 August 2022, BOOK, Xiao, Weidong,weblink Photovoltaic Power System: Modeling, Design, and Control, 24 July 2017, John Wiley & Sons, 978-1-119-28034-7, 288, 22 August 2022, {{Better source needed|reason=The current source is too old. All those battery types still common with solar?|date=November 2022}}Lithium-ion batteries have the potential to replace lead-acid batteries in the near future, as they are being intensively developed and lower prices are expected due to economies of scale provided by large production facilities such as the Tesla Gigafactory 1. In addition, the Li-ion batteries of plug-in electric cars may serve as future storage devices in a vehicle-to-grid system. Since most vehicles are parked an average of 95% of the time, their batteries could be used to let electricity flow from the car to the power lines and back.Retired electric vehicle (EV) batteries can be repurposed.JOURNAL, Al-Alawi, Mohammed Khalifa, Cugley, James, Hassanin, Hany, 2022-12-01, Techno-economic feasibility of retired electric-vehicle batteries repurpose/reuse in second-life applications: A systematic review,weblink Energy and Climate Change, 3, 100086, 10.1016/j.egycc.2022.100086, 2666-2787, Other rechargeable batteries used for distributed PV systems include, sodium–sulfur and vanadium redox batteries, two prominent types of a molten salt and a flow battery, respectively.WEB, Hoppmann, Joern, Volland, Jonas, Schmidt, Tobias S., Hoffmann, Volker H., July 2014, The Economic Viability of Battery Storage for Residential Solar Photovoltaic Systems – A Review and a Simulation Model,weblink live,weblink" title="web.archive.org/web/20150403122002weblink">weblink 3 April 2015, ETH Zürich, Harvard University, dmy-all, WEB, Gerdes, Justin, Solar Energy Storage About To Take Off In Germany and California,weblink live,weblink 2017-07-29, 2023-02-08, Forbes, en, NEWS, Associated Press,weblink Tesla launches Powerwall home battery with aim to revolutionize energy consumption, 1 May 2015, live,weblink" title="web.archive.org/web/20150607013500weblink">weblink 7 June 2015, dmy-all, (File:Seasonal cycle of capacity factors for wind and photovoltaics in Europe under idealized assumptions.png|thumb|upright=1.2|Seasonal cycle of capacity factors for wind and photovoltaics in Europe shown under idealized assumptions. The figure illustrates the balancing effects of wind and solar energy at the seasonal scale (Kaspar et al., 2019).JOURNAL, Kaspar, Frank, Borsche, Michael, Pfeifroth, Uwe, Trentmann, Jörg, Drücke, Jaqueline, Becker, Paul, 2019-07-02, A climatological assessment of balancing effects and shortfall risks of photovoltaics and wind energy in Germany and Europe,weblink live,weblink 2021-11-24, Advances in Science and Research, English, Copernicus GmbH, 16, 119–128, 10.5194/asr-16-119-2019, free, 2019AdSR...16..119K, 198316727, )

Other technologies

Solar power plants, while they can be curtailed, usually simply output as much power as possible. Therefore in an electricity system without sufficient grid energy storage, generation from other sources (coal, biomass, natural gas, nuclear, hydroelectricity) generally go up and down in reaction to the rise and fall of solar electricity and variations in demand (see load following power plant). Conventional hydroelectric dams work very well in conjunction with solar power; water can be held back or released from a reservoir as required. Where suitable geography is not available, pumped-storage hydroelectricity can use solar power to pump water to a high reservoir on sunny days, then the energy is recovered at night and in bad weather by releasing water via a hydroelectric plant to a low reservoir where the cycle can begin again.WEB, Pumped Hydro Storage, Electricity Storage Association,weblink 31 July 2008, dead,weblink" title="web.archive.org/web/20080621052054weblink">weblink 21 June 2008, dmy, While hydroelectric and natural gas plants can quickly respond to changes in load; coal, biomass and nuclear plants usually take considerable time to respond to load and can only be scheduled to follow the predictable variation. Depending on local circumstances, beyond about 20–40% of total generation, grid-connected intermittent sources like solar tend to require investment in some combination of grid interconnections, energy storage or demand side management. In countries with high solar generation, such as Australia, electricity prices may become negative in the middle of the day when solar generation is high, thus incentivizing new battery storage.WEB, Parkinson, Giles, 2022-10-23, "We don't need solar technology breakthroughs, we just need connections",weblink 2022-11-08, RenewEconomy, en-AU, WEB, Vorrath, Sophie, 2022-10-17, MPower gets green light to connect solar battery projects, cash in on negative pricing,weblink 2022-11-08, RenewEconomy, en-AU, The combination of wind and solar PV has the advantage that the two sources complement each other because the peak operating times for each system occur at different times of the day and year.JOURNAL, Nyenah, Emmanuel, Sterl, Sebastian, Thiery, Wim, 2022-05-01, Pieces of a puzzle: solar-wind power synergies on seasonal and diurnal timescales tend to be excellent worldwide, Environmental Research Communications, en, 4, 5, 055011, 10.1088/2515-7620/ac71fb, 2022ERCom...4e5011N, 249227821, 2515-7620, free, The power generation of such solar hybrid power systems is therefore more constant and fluctuates less than each of the two component subsystems.WEB, 2 July 2012, Hybrid Wind and Solar Electric Systems,weblink live,weblink" title="web.archive.org/web/20150526061658weblink">weblink 26 May 2015, United States Department of Energy, dmy-all, Solar power is seasonal, particularly in northern/southern climates, away from the equator, suggesting a need for long term seasonal storage in a medium such as hydrogen or pumped hydroelectric.JOURNAL,weblink Seasonal Energy Storage in a Renewable Energy System, Proceedings of the IEEE, 2012, 10.1109/JPROC.2011.2105231, 9195655, 30 April 2018, dead,weblink 8 November 2016, dmy-all, Converse, Alvin O., 100, 2, 401–409,

Environmental effects

{{Further|Concentrated_solar_power#Environmental_effects}}(File:Greenhouse gas emissions per energy source.png|thumb|upright=1.2|Greenhouse gas emissions per energy source. Solar power is one of the sources with the least greenhouse gas emissions.)File:Blick vom aussichtsturm hörlitz4.jpg|thumb|Part of the Senftenberg Solarpark, a solar photovoltaic power plant located on former open-pit mining areas close to the city of SenftenbergSenftenbergSolar power is cleaner than electricity from fossil fuels, so can be better for the environment.WEB, Solar energy and the environment – U.S. Energy Information Administration (EIA),weblink 2023-05-31, www.eia.gov, Solar power does not lead to harmful emissions during operation, but the production of the panels creates some pollution. A 2021 study estimated the carbon footprint of manufacturing monocrystalline panels at 515 g {{CO2}}/kWp in the US and 740 g {{CO2}}/kWp in China,BOOK, Anctil, Annick, 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC), Comparing the carbon footprint of monocrystalline silicon solar modules manufactured in China and the United States, June 2021,weblink 1–3, 10.1109/PVSC43889.2021.9518632, 978-1-6654-1922-2, 237332457, but this is expected to fall as manufacturers use more clean electricity and recycled materials.WEB, 2022-09-21, Solar power's potential limited unless "you do everything perfectly" says solar scientist,weblink 2022-10-15, Dezeen, en, Solar power carries an upfront cost to the environment via production with a carbon payback time of several years {{As of|2022|lc=y}}, but offers clean energy for the remainder of their 30-year lifetime.WEB, Aging Gracefully: How NREL Is Extending the Lifetime of Solar Modules,weblink 2022-10-15, www.nrel.gov, en, The life-cycle greenhouse-gas emissions of solar farms are less than 50 gram (g) per kilowatt-hour (kWh),JOURNAL, Zhu, Xiaonan, Wang, Shurong, Wang, Lei, April 2022, Life cycle analysis of greenhouse gas emissions of China's power generation on spatial and temporal scale, Energy Science & Engineering, en, 10, 4, 1083–1095, 10.1002/ese3.1100, 2022EneSE..10.1083Z, 247443046, 2050-0505, free, WEB, Carbon Neutrality in the UNECE Region: Integrated Life-cycle Assessment of Electricity Sources,weblink 49, WEB, Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics,weblink but with battery storage could be up to 150 g/kWh.JOURNAL, Mehedi, Tanveer Hassan, Gemechu, Eskinder, Kumar, Amit, 2022-05-15, Life cycle greenhouse gas emissions and energy footprints of utility-scale solar energy systems,weblink Applied Energy, en, 314, 118918, 10.1016/j.apenergy.2022.118918, 2022ApEn..31418918M, 247726728, 0306-2619, In contrast, a combined cycle gas-fired power plant without carbon capture and storage emits around 500 g/kWh, and a coal-fired power plant about 1000 g/kWh.WEB, Life Cycle Assessment Harmonization,weblink 2021-12-04, www.nrel.gov, en, Similar to all energy sources where their total life cycle emissions are mostly from construction, the switch to low carbon power in the manufacturing and transportation of solar devices would further reduce carbon emissions.Lifecycle surface power density of solar power varies but averages about 7 W/m2, compared to about 240 for nuclear power and 480 for gas.JOURNAL, 2018-12-01, The spatial extent of renewable and non-renewable power generation: A review and meta-analysis of power densities and their application in the U.S., Energy Policy, en, 123, 83–91, 10.1016/j.enpol.2018.08.023, 0301-4215, free, Van Zalk, John, Behrens, Paul, 2018EnPol.123...83V, 1887/64883, free, However when the land required for gas extraction and processing is accounted for, gas power is estimated to have not much higher power density than solar. PV requires much larger amounts of land surface to produce the same nominal amount of energy as sources{{Which|date=May 2023}} with higher surface power density and capacity factor. According to a 2021 study, obtaining 25% to 80% of electricity from solar farms in their own territory by 2050 would require the panels to cover land ranging from 0.5% to 2.8% of the European Union, 0.3% to 1.4% in India, and 1.2% to 5.2% in Japan and South Korea.JOURNAL, van de Ven, Dirk-Jan, Capellan-Peréz, Iñigo, Arto, Iñaki, Cazcarro, Ignacio, de Castro, Carlos, Patel, Pralit, Gonzalez-Eguino, Mikel, 2021-02-03, The potential land requirements and related land use change emissions of solar energy, Scientific Reports, en, 11, 1, 2907, 2045-2322, 10.1038/s41598-021-82042-5, 33536519, 7859221, 2021NatSR..11.2907V, Occupation of such large areas for PV farms could drive residential opposition as well as lead to deforestation, removal of vegetation and conversion of farm land.WEB, Diab, Khaled, There are grounds for concern about solar power,weblink 2021-04-15, www.aljazeera.com, en, However some countries, such as South Korea and Japan, use land for agriculture under PV,WEB, Staff, Carbon Brief, 2022-08-25, Factcheck: Is solar power a 'threat' to UK farmland?,weblink 2022-09-15, Carbon Brief, en, WEB, Oda, Shoko, 2022-05-21, Electric farms in Japan are using solar power to grow profits and crops,weblink 2022-10-14, The Japan Times, en-US, or floating solar,WEB, Gerretsen, Isabelle, The floating solar panels that track the Sun,weblink 2022-11-29, www.bbc.com, en, together with other low-carbon power sources.WEB, Pollard, Jim, 2023-05-29, Wind Power Body Plans to Provide a Third of Japan's Electricity,weblink 2023-05-31, Asia Financial, en-US, WEB, Clean power in South Korea,weblink Worldwide land use has minimal ecological impact.JOURNAL, Dunnett, Sebastian, Holland, Robert A., Taylor, Gail, Eigenbrod, Felix, 2022-02-08, Predicted wind and solar energy expansion has minimal overlap with multiple conservation priorities across global regions, Proceedings of the National Academy of Sciences, en, 119, 6, 10.1073/pnas.2104764119, free, 0027-8424, 35101973, 8832964, 2022PNAS..11904764D, Land use can be reduced to the level of gas power by installing on buildings and other built up areas.WEB, How does the land use of different electricity sources compare?,weblink 2022-11-03, Our World in Data, Harmful materials are used in the production of solar panels, but generally in small amounts.JOURNAL, Rabaia, Malek Kamal Hussien, Abdelkareem, Mohammad Ali, Sayed, Enas Taha, Elsaid, Khaled, Chae, Kyu-Jung, Wilberforce, Tabbi, Olabi, A. G., 2021, Environmental impacts of solar energy systems: A review,weblink Science of the Total Environment, en, 754, 141989, 10.1016/j.scitotenv.2020.141989, 32920388, 2021ScTEn.754n1989R, 221671774, 0048-9697, {{As of|2022}}, the environmental impact of perovskite is difficult to estimate, but there is some concern that lead may be a problem.JOURNAL, Urbina, Antonio, 2022-10-26, Sustainability of photovoltaic technologies in future net-zero emissions scenarios, Progress in Photovoltaics: Research and Applications, 31, 12, en, 1255–1269, 10.1002/pip.3642, 1062-7995, 253195560, the apparent contradiction that can arise from the fact that large PV plants occupy more land than the relatively compact coal or gas plants is due to the inclusion in the calculation of impacts in land occupation arising from coal mining and oil or gas extraction; if they are included, the impact on land occupation is larger for fossil fuels., free, A 2021 International Energy Agency study projects the demand for copper will double by 2040. The study cautions that supply needs to increase rapidly to match demand from large-scale deployment of solar and required grid upgrades.WEB, 2021-05-05, Renewable revolution will drive demand for critical minerals,weblink 2021-05-05, RenewEconomy, en-AU, WEB, 5 May 2021, Clean energy demand for critical minerals set to soar as the world pursues net zero goals – News,weblink 2021-05-05, IEA, en-GB, More tellurium and indium may also be needed. Recycling may help. As solar panels are sometimes replaced with more efficient panels, the second-hand panels are sometimes reused in developing countries, for example in Africa.NEWS, Used Solar Panels Are Powering the Developing World,weblink 2022-09-15, Bloomberg.com, 25 August 2021, Several countries have specific regulations for the recycling of solar panels.WEB, US EPA, OLEM, 2021-08-23, End-of-Life Solar Panels: Regulations and Management,weblink 2022-09-15, www.epa.gov, en, WEB, The Proposed Legal Framework On Responsibility Of Producers And...,weblink 2022-09-15, www.roedl.com, en-us, JOURNAL, Majewski, Peter, Al-shammari, Weam, Dudley, Michael, Jit, Joytishna, Lee, Sang-Heon, Myoung-Kug, Kim, Sung-Jim, Kim, 2021-02-01, Recycling of solar PV panels – product stewardship and regulatory approaches,weblink Energy Policy, en, 149, 112062, 2021EnPol.14912062M, 10.1016/j.enpol.2020.112062, 0301-4215, 230529644, Although maintenance cost is already low compared to other energy sources,JOURNAL, Gürtürk, Mert, 2019-03-15, Economic feasibility of solar power plants based on PV module with levelized cost analysis,weblink Energy, en, 171, 866–878, 10.1016/j.energy.2019.01.090, 2019Ene...171..866G, 116733543, 0360-5442, some academics have called for solar power systems to be designed to be more repairable.JOURNAL, Cross, Jamie, Murray, Declan, 2018-10-01, The afterlives of solar power: Waste and repair off the grid in Kenya, Energy Research & Social Science, en, 44, 100–109, 10.1016/j.erss.2018.04.034, 53058260, 2214-6296, free, 2018ERSS...44..100C, BOOK, Jang, Esther, Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems, Barela, Mary Claire, Johnson, Matt, Martinez, Philip, Festin, Cedric, Lynn, Margaret, Dionisio, Josephine, Heimerl, Kurtis, 2018-04-19, Association for Computing Machinery, 978-1-4503-5620-6, CHI '18, New York, New York, US, 1–12, Crowdsourcing Rural Network Maintenance and Repair via Network Messaging, 10.1145/3173574.3173641,weblink 4950067, A very small proportion of solar power is concentrated solar power. Concentrated solar power may use much more water than gas-fired power. This can be a problem, as this type of solar power needs strong sunlight so is often built in deserts.WEB, Water consumption solution for efficient concentrated solar power {{!, Research and Innovation |url=https://ec.europa.eu/research-and-innovation/en/projects/success-stories/all/water-consumption-solution-efficient-concentrated-solar-power |access-date=2021-12-04 |website=ec.europa.eu |language=en}}

Politics

(File:202307 Survey - comfortable with solar wind nuclear in my community.svg|thumb|upright=1.2|Acceptance of wind and solar facilities in one's community is stronger among U.S. Democrats (blue), while acceptance of nuclear power plants is stronger among U.S. Republicans (red).NEWS, Chiu, Allyson, Guskin, Emily, Clement, Scott, Americans don't hate living near solar and wind farms as much as you might think,weblink The Washington Post, 3 October 2023,weblink 3 October 2023, live, )Solar production cannot be cut off by geopolitics once installed, unlike oil and gas, which contributes to energy security.WEB, Making solar a source of EU energy security {{!, Think Tank {{!}} European Parliament |url=https://www.europarl.europa.eu/thinktank/en/document/EPRS_ATA(2022)733587 |access-date=2022-11-03 |website=www.europarl.europa.eu |language=en}}{{As of|2022}} over 40% of global polysilicon manufacturing capacity is in Xinjiang in China,NEWS, Blunt, Katherine, Dvorak, Phred, 2022-08-09, WSJ News Exclusive {{!, U.S. Solar Shipments Are Hit by Import Ban on China's Xinjiang Region |language=en-US |work=The Wall Street Journal |url=https://www.wsj.com/articles/u-s-solar-shipments-are-hit-by-import-ban-on-chinas-xinjiang-region-11660037401 |access-date=2022-09-08 |issn=0099-9660}} which raises concerns about human rights violations (Xinjiang internment camps) as well as supply chain dependency.WEB, 2021-02-10, Fears over China's Muslim forced labor loom over EU solar power,weblink 2021-04-15, Politico, en-US,

See also

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• 100% renewable energy
• Cost of electricity by source
• Gravity battery
• Index of solar energy articles
• List of cities by sunshine duration
• List of photovoltaic power stations
• List of solar thermal power stations
• List of solar-powered products
• Renewable energy commercialization
• Solar energy
• Solar lamp
• Solar vehicle
• Sustainable energy
• Thin-film solar cell
• Timeline of solar cells

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References

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Bibliography

• BOOK, {{google books, y, xHFK9cM77a8C, 50, |title=From space to Earth: the story of solar electricity|last=Perlin|first=John|publisher=Earthscan|year=1999|isbn=978-0-937948-14-9|page=50}}

Further reading

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• BOOK, Sivaram, Varun, Taming the Sun: Innovation to Harness Solar Energy and Power the Planet, Cambridge, Massachusetts, MIT Press, 2018, 978-0-262-03768-6,

External links

• Solar energy and the environment at U.S. Energy Information Administration

{{Commons category|Solar energy|Solar power}}{{Solar energy}}{{Solar power by country}}{{Photovoltaics}}{{Electricity generation|state=autocollapse}}{{Renewable energy by country}}