Solar power

The first three concentrated solar power (CSP) units of Spain's Solnova Solar Power Station in the foreground, with the PS10 and PS20 solar power towers in the background

Estimated solar energy available for power generation. The map shows the average daily/yearly sum of electricity production from a 1 kW-peak grid-connected solar PV power plant covering the period from 1994/1999/2007 (depending on the geographical region) to 2018.<ref>"Global Solar Atlas". globalsolaratlas.info. Retrieved 12 August 2022.</ref>

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.<ref>"Energy Sources: Solar". Department of Energy. Archived from the original on 14 April 2011. Retrieved 19 April 2011.</ref> 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 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,<ref name=":8">Gabbatiss, Josh (12 January 2024). "Analysis: World will add enough renewables in five years to power US and Canada". Carbon Brief. Retrieved 11 February 2024.</ref> with both millions of rooftop installations and gigawatt-scale photovoltaic power stations continuing to be built.

In 2023, solar generated 5% of the world's electricity,<ref>"Executive summary – Renewables 2023 – Analysis". IEA. Retrieved 16 January 2024.</ref> compared to 1% in 2015, when the Paris Agreement to limit climate change was signed.<ref name="GER">"Global Electricity Review 2022". Ember. 29 March 2022. Retrieved 3 April 2022.</ref> Along with onshore wind, in most countries, the cheapest levelised cost of electricity for new installations is utility-scale solar.<ref>"2023 Levelized Cost Of Energy+". Lazard. Retrieved 14 June 2023.</ref><ref>"Executive summary – Renewable Energy Market Update - June 2023 – Analysis". IEA. Retrieved 14 June 2023.</ref>

Almost half the solar power installed in 2022 was rooftop.<ref name=":7">Norman, Will (13 June 2023). "Through the roof: 49.5% of world's PV additions were rooftop in 2022 – SolarPower Europe". PV Tech. Retrieved 14 June 2023.</ref> Much more low-carbon power is needed for electrification and to limit climate change.<ref name=":8" /> The International Energy Agency said in 2022 that more effort was needed for grid integration and the mitigation of policy, regulation and financing challenges.<ref>"Solar PV – Analysis". IEA. Retrieved 10 November 2022.</ref>

Potential

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.<ref name="World Energy Assessment">Goldemberg, José; UNDP, eds. (2000). World energy assessment: energy and the challenge of sustainability (1. print ed.). New York, NY: United Nations Development Programme. ISBN 978-92-1-126126-4.</ref> Daytime cloud cover can reduce the light available for solar cells. Besides, land availability 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) uses mirrors or lenses to concentrate sunlight to extreme heat to eventually make steam, which is converted into electricity by a turbine.

Photovoltaic cells

Schematics of a grid-connected residential PV power system<ref name="SolarCells_Section10_2">Solar Cells and their Applications Second Edition, Lewis Fraas, Larry Partain, Wiley, 2010, ISBN 978-0-470-44633-1, Section10.2.</ref>

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.<ref>Perlin 1999, p. 147</ref> The German industrialist Ernst Werner von Siemens was among those who recognized the importance of this discovery.<ref>Perlin 1999, pp. 18–20</ref> In 1931, the German engineer Bruno Lange developed a photo cell using silver selenide in place of copper oxide,<ref>Corporation, Bonnier (June 1931). "Magic Plates, Tap Sun For Power". Popular Science: 41. Retrieved 19 April 2011.</ref> 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.<ref>Perlin 1999, p. 29</ref> These early solar cells cost US$286/watt and reached efficiencies of 4.5–6%.<ref>Perlin 1999, pp. 29–30, 38</ref> In 1957, Mohamed M. Atalla developed the process of silicon surface passivation by thermal oxidation at Bell Labs.<ref>Black, Lachlan E. (2016). New Perspectives on Surface Passivation: Understanding the Si-Al2O3 Interface (PDF). Springer. p. 13. ISBN 9783319325217.</ref><ref name="Lojek">Lojek, Bo (2007). History of Semiconductor Engineering. Springer Science & Business Media. pp. 120& 321–323. ISBN 9783540342588.</ref> The surface passivation process has since been critical to solar cell efficiency.<ref>Black, Lachlan E. (2016). New Perspectives on Surface Passivation: Understanding the Si-Al2O3 Interface (PDF). Springer. ISBN 9783319325217.</ref>

As of 2022^[update] over 90% of the market is crystalline silicon.<ref name=":5" /> 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.<ref name="SolarCells_Section10_2" /> 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.<ref name="SolarCells_Section10_2" />

Many residential PV systems are connected to the grid wherever available, especially in developed countries with large markets.<ref name="IEAPVPS2009_Fig3">"Trends in Photovoltaic Applications Survey report of selected IEA countries between 1992 and 2009, IEA-PVPS". Archived from the original on 25 May 2017. Retrieved 8 November 2011.</ref> 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.<ref name=Cooldown_20240117/> Other configurations include floating solar farms, placing solar canopies over parking lots, and installing solar panels on roofs.<ref name=Cooldown_20240117>Budin, Jeremiah (17 January 2024). "Game-Changing Solar Power Technology to Get First US Installation: Valuable Land is almost Completely Preserved". The Cooldown. Archived from the original on 17 January 2024.</ref>

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).<ref>"Thin-Film Solar Panels | American Solar Energy Society".</ref>

Perovskite solar cells

page-not-found

Concentrated solar power

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.<ref>"How CSP Works: Tower, Trough, Fresnel or Dish". Solarpaces. 11 June 2018. Retrieved 14 March 2020.</ref>

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.<ref name="Martin 2005">Martin and Goswami (2005), p. 45</ref> Thermal storage efficiently allows overnight electricity generation,<ref>Stephen Lacey (6 July 2011). "Spanish CSP Plant with Storage Produces Electricity for 24 Hours Straight". Archived from the original on 12 October 2012.</ref> thus complementing PV.<ref>"More countries are turning to this technology for clean energy. It's coming to Australia". ABC News. 5 October 2022. Retrieved 4 November 2022.</ref> CSP generates a very small share of solar power and in 2022 the IEA said that CSP should be better paid for its storage.<ref>"Renewable Electricity – Analysis". IEA. Retrieved 4 November 2022.</ref>

As of 2021^[update] the levelized cost of electricity from CSP is over twice that of PV.<ref>"Renewable Power Generation Costs in 2021". irena.org. 13 July 2022. Retrieved 4 November 2022.</ref> However, their very high temperatures may prove useful to help decarbonize industries (perhaps via hydrogen) which need to be hotter than electricity can provide.<ref>Casey, Tina (30 September 2022). "US Energy Dept. Still Holds Torch For Concentrating Solar Power". CleanTechnica. Retrieved 4 November 2022.</ref>

Hybrid systems

A hybrid system combines solar with energy storage and/or one or more other forms of generation. Hydro,<ref>Garanovic, Amir (10 November 2021). "World's largest hydro-floating solar hybrid comes online in Thailand". Offshore Energy. Retrieved 7 November 2022.</ref><ref>Ming, Bo; Liu, Pan; Guo, Yi (1 January 2022), Jurasz, Jakub; Beluco, Alexandre (eds.), "Chapter 20 - Operations management of large hydro–PV hybrid power plants: case studies in China", Complementarity of Variable Renewable Energy Sources, Academic Press, pp. 439–502, ISBN 978-0-323-85527-3, retrieved 7 November 2022</ref> wind<ref>"World's largest wind-solar hybrid complex goes online in India". Renewablesnow.com. Retrieved 7 November 2022.</ref><ref>Todorović, Igor (4 November 2022). "China completes world's first hybrid offshore wind-solar power plant". Balkan Green Energy News. Retrieved 7 November 2022.</ref> and batteries<ref>Which?. "Solar panel battery storage". Which?. Retrieved 7 November 2022.</ref> 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.<ref>Brumana, Giovanni; Franchini, Giuseppe; Ghirardi, Elisa; Perdichizzi, Antonio (1 May 2022). "Techno-economic optimization of hybrid power generation systems: A renewables community case study". Energy. 246: 123427. doi:10.1016/j.energy.2022.123427. ISSN 0360-5442. S2CID 246695199.</ref><ref>Wang, Zhenni; Wen, Xin; Tan, Qiaofeng; Fang, Guohua; Lei, Xiaohui; Wang, Hao; Yan, Jinyue (1 August 2021). "Potential assessment of large-scale hydro-photovoltaic-wind hybrid systems on a global scale". Renewable and Sustainable Energy Reviews. 146: 111154. doi:10.1016/j.rser.2021.111154. ISSN 1364-0321. S2CID 235925315.</ref> There is a lot of 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,<ref>Todorović, Igor (22 July 2022). "Portugal, Switzerland launch pumped storage hydropower plants of over 2 GW in total". Balkan Green Energy News. Retrieved 8 November 2022.</ref> and existing power lines can sometimes be used.<ref>Bank (ADB), Asian Development. "ADB Partnership Report 2019: Building Strong Partnerships for Shared Progress". Asian Development Bank. Retrieved 7 November 2022.</ref><ref>Merlet, Stanislas; Thorud, Bjørn (18 November 2020). "Floating solar power connected to hydropower might be the future for renewable energy". sciencenorway.no. Retrieved 7 November 2022.</ref>

Development and deployment

The share of electricity production from solar, 2022<ref>"Share of electricity production from solar". *Our World in Data*. Retrieved 15 August 2023.</ref>

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.<ref>Scientific American. Munn & Company. 10 April 1869. p. 227.</ref> Charles Fritts installed the world's first rooftop photovoltaic solar array, using 1%-efficient selenium cells, on a New York City roof in 1884.<ref>"Photovoltaic Dreaming 1875--1905: First Attempts At Commercializing PV - CleanTechnica". cleantechnica.com. 31 December 2014. Archived from the original on 25 May 2017. Retrieved 30 April 2018.</ref> 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.<ref>Butti and Perlin (1981), p. 63, 77, 101</ref> Bell Telephone Laboratories’ 1950s research used silicon wafers with a very thin coating of boron. The “Bell Solar Battery” was described as 6% efficient, with a square yard of the panels generating 50 watts.<ref>”The Bell Solar Battery” (advertisement). Audio, July 1964, 15.</ref> The first satellite with solar panels was launched in 1957.<ref name="NRL">"Vanguard I The World's Oldest Satellite Still in Orbit". Archived from the original on 21 March 2015. Retrieved 24 September 2007. This article incorporates text from this source, which is in the public domain.</ref>

By the 1970s, solar panels were still too expensive for much other than satellites.<ref name="Levy">Levy, Adam (13 January 2021). "The dazzling history of solar power". Knowable Magazine. doi:10.1146/knowable-011321-1. S2CID 234124275. Retrieved 25 March 2022.</ref> 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.<ref>"The Solar Energy Book-Once More." Mother Earth News 31:16–17, Jan. 1975</ref> 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.<ref>Butti and Perlin (1981), p. 249</ref><ref>Yergin (1991), pp. 634, 653–673</ref>

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).<ref>"Chronicle of Fraunhofer-Gesellschaft". Fraunhofer-Gesellschaft. Archived from the original on 12 December 2007. Retrieved 4 November 2007.</ref> 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.<ref name="Levy"/> 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.<ref name="Levy"/><ref>Solar: photovoltaic: Lighting Up The World retrieved 19 May 2009 Archived 13 August 2010 at the Wayback Machine</ref> 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.<ref>Colville, Finlay (30 January 2017). "Top-10 solar cell producers in 2016". PV-Tech. Archived from the original on 2 February 2017.</ref><ref>Ball, Jeffrey; et al. (21 March 2017). "The New Solar System - Executive Summary" (PDF). Stanford University Law School, Steyer-Taylor Center for Energy Policy and Finance. Archived (PDF) from the original on 20 April 2017. Retrieved 27 June 2017.</ref> Although concentrated solar power capacity grew more than tenfold, it remained a tiny proportion of the total,<ref name="ren21-gsr-2014"> REN21 (2014). "Renewables 2014: Global Status Report" (PDF). Archived (PDF) from the original on 15 September 2014.{{cite web}}: CS1 maint: numeric names: authors list (link)</ref>^: 51 because the cost of utility-scale solar PV fell by 85% between 2010 and 2020, while CSP costs only fell 68% in the same timeframe.<ref>Santamarta, Jose. "The cost of Concentrated Solar Power declined by 16%". HELIOSCSP. Retrieved 15 September 2022.</ref>

2020s

Despite the rising cost of materials, such as polysilicon, during the 2021–2022 global energy crisis,<ref>"What is the impact of increasing commodity and energy prices on solar PV, wind and biofuels? – Analysis". IEA. Retrieved 4 April 2022.</ref> utility scale solar was still the cheapest energy source in many countries due to the rising costs of other energy sources, such as natural gas.<ref>"Levelized Cost Of Energy, Levelized Cost Of Storage, and Levelized Cost Of Hydrogen". Lazard.com. Retrieved 4 April 2022.</ref> In 2022, global solar generation capacity exceeded 1 TW for the first time.<ref>"World Installs a Record 168 GW of Solar Power in 2021, enters Solar Terawatt Age - SolarPower Europe".</ref> However, fossil-fuel subsidies have slowed the growth of solar generation capacity.<ref>McDonnell, Tim (29 August 2022). "Soaring fossil fuel subsidies are holding back clean energy". Quartz. Retrieved 4 September 2022.</ref>

Current status

About half of installed capacity is utility scale.<ref name=":2">Dana Olson; Bent Erik Bakken. "Utility-scale solar PV: From big to biggest". Det Norske Veritas. Retrieved 15 January 2024.</ref>

Forecasts

Most new renewable capacity between 2022 and 2027 is forecast to be solar, surpassing coal as the largest source of installed power capacity.<ref name=":4">"Renewable electricity – Renewables 2022 – Analysis". IEA. Retrieved 12 December 2022.</ref>^: 26 Utility scale is forecast to become the largest source of electricity in all regions except sub-Saharan Africa by 2050.<ref name=":2" />

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.<ref>Cork, University College. "Assessing global electricity generation potential from rooftop solar photovoltaics". techxplore.com. Retrieved 11 October 2021.</ref>

Photovoltaic power stations

Lua error in Module:TNT at line 159: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/Module:Excerpt.tab.

Concentrating solar power stations

Ivanpah Solar Electric Generating System with all three towers under load

Commercial 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.<ref>What is peak demand? Archived 11 August 2012 at the Wayback Machine, Energex.com.au website.</ref>

Economics

Cost per watt

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.<ref>Nian, Victor; Mignacca, Benito; Locatelli, Giorgio (15 August 2022). "Policies toward net-zero: Benchmarking the economic competitiveness of nuclear against wind and solar energy". Applied Energy. 320: 119275. Bibcode:2022ApEn..32019275N. doi:10.1016/j.apenergy.2022.119275. ISSN 0306-2619. S2CID 249223353.</ref> Thus upfront capital and financing costs make up 80 to 90% of the cost of solar power.<ref name=":4" />^: 165

Some countries are considering price caps,<ref>"EU expects to raise €140bn from windfall tax on energy firms". the Guardian. 14 September 2022. Retrieved 15 September 2022.</ref> whereas others prefer contracts for difference.<ref>"The EU's energy windfall tax gives UK ministers a yardstick for their talks". the Guardian. 14 September 2022. Retrieved 15 September 2022.</ref>

In many countries solar power is the cheapest source of electricity.<ref>"Why wind and solar are key solutions to combat climate change". Ember. 9 February 2024. Retrieved 11 February 2024.</ref> 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.<ref name="ppa for 2970MW">"Saudi Arabia signed Power Purchase Agreement for 2,970MW Solar PV Projects". saudigulfprojects.com. 8 April 2021. Retrieved 28 August 2022.</ref>

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.<ref name="timilsina_solar_2012">Timilsina, Govinda R.; Kurdgelashvili, Lado; Narbel, Patrick A. (1 January 2012). "Solar energy: Markets, economics and policies". Renewable and Sustainable Energy Reviews. 16 (1): 449–465. doi:10.1016/j.rser.2011.08.009. ISSN 1364-0321.</ref>

In 2021 in the US, residential solar cost from 2 to 4 dollars/watt (but solar shingles cost much more)<ref>"Solar Shingles Vs. Solar Panels: Cost, Efficiency & More (2021)". EcoWatch. 8 August 2021. Retrieved 25 August 2021.</ref> and utility solar costs were around $1/watt.<ref>"Solar Farms: What Are They and How Much Do They Cost? | EnergySage". Solar News. 18 June 2021. Retrieved 25 August 2021.</ref>

Productivity by location

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.<ref name="ReferenceA">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 (15 July 2021). "Low-cost renewable electricity as the key driver of the global energy transition towards sustainability". Energy. 227: 120467. doi:10.1016/j.energy.2021.120467. ISSN 0360-5442. S2CID 233706454.</ref>^: 8 Modelling by Exeter University suggests that by 2030 solar will be cheapest in all countries except for some in north-east Europe.<ref>"Is a solar future inevitable?" (PDF). University of Exeter. Retrieved 2 October 2023.</ref>

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.<ref>"Daytime Cloud Fraction Coast lines evident". Archived from the original on 22 August 2017. Retrieved 22 August 2017.</ref><ref>"Sunshine". Archived from the original on 23 September 2015. Retrieved 6 September 2015.</ref> 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.<ref>"Living in the Sun Belt : The Solar Power Potential for the Middle East". 27 July 2016. Archived from the original on 26 August 2017. Retrieved 22 August 2017.</ref>

So 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 places.<ref name="ReferenceA"/>^: 8

Different measurements of solar irradiance (direct normal irradiance, global horizontal irradiance) are mapped below:

North America
South America
Europe
Africa and Middle East
South and South-East Asia
Australia
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.<ref>"Money saved by producing electricity from PV and Years for payback". Archived from the original on 28 December 2014.</ref> 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.<ref name="iea-pvps-trends-2014">Trends in Photovoltaic Applications 2014 (PDF) (Report). IEA-PVPS. 2014. Archived (PDF) from the original on 25 May 2017.</ref> Moreover, separate self-consumption incentives have been used in e.g., Germany and Italy.<ref name="iea-pvps-trends-2014"/> Grid interaction regulation has also included limitations of grid feed-in in some regions in Germany with high amounts of installed PV capacity.<ref name="iea-pvps-trends-2014"/><ref>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. Bibcode:2013ITSE....4..534S. doi:10.1109/TSTE.2012.2198925. S2CID 47032066.</ref> By increasing self-consumption, the grid feed-in can be limited without curtailment, which wastes electricity.<ref name="salpakari-lund-2016">Salpakari, Jyri; Lund, Peter (2016). "Optimal and rule-based control strategies for energy flexibility in buildings with PV". Applied Energy. 161: 425–436. Bibcode:2016ApEn..161..425S. doi:10.1016/j.apenergy.2015.10.036. S2CID 59037572.</ref>

A good match between generation and consumption is key for high self-consumption. The match can be improved with batteries or controllable electricity consumption.<ref name="salpakari-lund-2016"/> However, batteries are expensive, and profitability may require the provision of other services from them besides self-consumption increase,<ref name="rmi-battery-2015">Fitzgerald, Garrett; Mandel, James; Morris, Jesse; Touati, Hervé (2015). The Economics of Battery Energy Storage (PDF) (Report). Rocky Mountain Institute. Archived from the original (PDF) on 30 November 2016.</ref> for example avoiding power outages.<ref>"The Value of Electricity Reliability: Evidence from Battery Adoption". Resources for the Future. Retrieved 14 June 2023.</ref> Hot water storage tanks with electric heating with heat pumps or resistance heaters can provide low-cost storage for self-consumption of solar power.<ref name="salpakari-lund-2016"/> 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.<ref name="salpakari-lund-2016"/>

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,<ref name=":6">"Germany boosts renewables with "biggest energy policy reform in decades"". Clean Energy Wire. 6 April 2022. Retrieved 8 November 2022.</ref> high tech job creation<ref>"Indigenizing Solar Manufacturing: Charting the Course to a Solar Self-Sufficient India - Saur Energy International". www.saurenergy.com. Retrieved 8 November 2022.</ref> and reduction of CO₂ emissions.<ref name=":6" />

Financial incentives for photovoltaics differ across countries, including Australia,<ref>"Renewable power incentives".</ref> China,<ref>China Racing Ahead of America in the Drive to Go Solar. Archived 6 July 2013 at the Wayback Machine</ref> Germany,<ref name="German PV market">"Power & Energy Technology - IHS Technology". Archived from the original on 2 January 2010.</ref> India,<ref>Ravi Shankar (20 July 2022). "What is the solar rooftop subsidy scheme/yojana? - Times of India". The Times of India. Retrieved 8 November 2022.</ref> Japan, and the United States and even across states within the US.

Net metering

In 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.<ref>"Net Metering original on 21 October 2012". dsireusa.org. Retrieved 12 October 2021.</ref> 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.<ref>"Net Metering and Interconnection - NJ OCE Web Site". Archived from the original on 12 May 2012.</ref>

Community solar

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.<ref>"Community Solar Basics". Energy.gov. Retrieved 17 September 2021.</ref>

Taxes

In some countries tariffs (import taxes) are imposed on imported solar panels.<ref>Philipp, Jennifer (7 September 2022). "Solar Power in Africa on the Rise". BORGEN. Retrieved 15 September 2022.</ref><ref>Busch, Marc L. (2 September 2022). "The mystery of India's new solar tariffs". The Hill. Retrieved 15 September 2022.</ref>

Grid integration

Thermal energy storage. The Andasol CSP plant uses tanks of molten salt to store solar energy.

Pumped-storage hydroelectricity (PSH). This facility in Geesthacht, Germany, also includes a solar array.

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.<ref>Carr (1976), p. 85</ref>

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 is well matched to daytime cooling demands.<ref>Ruggles, Tyler H.; Caldeira, Ken (1 January 2022). "Wind and solar generation may reduce the inter-annual variability of peak residual load in certain electricity systems". Applied Energy. 305: 117773. Bibcode:2022ApEn..30517773R. doi:10.1016/j.apenergy.2021.117773. ISSN 0306-2619. S2CID 239113921.</ref>

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%.<ref>"Advantages of Using Molten Salt". Sandia National Laboratory. Archived from the original on 5 June 2011. Retrieved 29 September 2007.</ref>

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.<ref>"PV Systems and Net Metering". Department of Energy. Archived from the original on 4 July 2008. Retrieved 31 July 2008.</ref> 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.<ref name="MohantyMuneerKolhe2015">Parimita Mohanty; Tariq Muneer; Mohan Kolhe (30 October 2015). Solar Photovoltaic System Applications: A Guidebook for Off-Grid Electrification. Springer. p. 91. ISBN 978-3-319-14663-8. Retrieved 22 August 2022.</ref><ref name="Xiao2017">Weidong Xiao (24 July 2017). Photovoltaic Power System: Modeling, Design, and Control. John Wiley & Sons. p. 288. ISBN 978-1-119-28034-7. Retrieved 22 August 2022.</ref>^{[better source needed]}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 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 EV batteries can be repurposed.<ref>Al-Alawi, Mohammed Khalifa; Cugley, James; Hassanin, Hany (1 December 2022). "Techno-economic feasibility of retired electric-vehicle batteries repurpose/reuse in second-life applications: A systematic review". Energy and Climate Change. 3: 100086. doi:10.1016/j.egycc.2022.100086. ISSN 2666-2787.</ref> 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.<ref name=ethz-Harvard>Joern Hoppmann; Jonas Volland; Tobias S. Schmidt; Volker H. Hoffmann (July 2014). "The Economic Viability of Battery Storage for Residential Solar Photovoltaic Systems - A Review and a Simulation Model". ETH Zürich, Harvard University. Archived from the original on 3 April 2015.</ref><ref>Gerdes, Justin. "Solar Energy Storage About To Take Off In Germany and California". Forbes. Archived from the original on 29 July 2017. Retrieved 8 February 2023.</ref><ref>"Tesla launches Powerwall home battery with aim to revolutionize energy consumption". Associated Press. 1 May 2015. Archived from the original on 7 June 2015.</ref>

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.<ref>"Pumped Hydro Storage". Electricity Storage Association. Archived from the original on 21 June 2008. Retrieved 31 July 2008.</ref>

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.<ref>Parkinson, Giles (23 October 2022). ""We don't need solar technology breakthroughs, we just need connections"". RenewEconomy. Retrieved 8 November 2022.</ref><ref>Vorrath, Sophie (17 October 2022). "MPower gets green light to connect solar battery projects, cash in on negative pricing". RenewEconomy. Retrieved 8 November 2022.</ref>

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.<ref>Nyenah, Emmanuel; Sterl, Sebastian; Thiery, Wim (1 May 2022). "Pieces of a puzzle: solar-wind power synergies on seasonal and diurnal timescales tend to be excellent worldwide". Environmental Research Communications. 4 (5): 055011. Bibcode:2022ERCom...4e5011N. doi:10.1088/2515-7620/ac71fb. ISSN 2515-7620. S2CID 249227821.</ref> The power generation of such solar hybrid power systems is therefore more constant and fluctuates less than each of the two component subsystems.<ref name="auto">"Hybrid Wind and Solar Electric Systems". United States Department of Energy. 2 July 2012. Archived from the original on 26 May 2015.</ref> 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.<ref>Converse, Alvin O. (2012). "Seasonal Energy Storage in a Renewable Energy System" (PDF). Proceedings of the IEEE. 100 (2): 401–409. doi:10.1109/JPROC.2011.2105231. S2CID 9195655. Archived from the original (PDF) on 8 November 2016. Retrieved 30 April 2018.</ref>

Environmental effects

Solar power is cleaner than electricity from fossil fuels,<ref name=":5" /> so can be good for the environment when it replaces that.<ref>"Solar energy and the environment - U.S. Energy Information Administration (EIA)". www.eia.gov. Retrieved 31 May 2023.</ref> Solar power does not lead to any harmful emissions during operation, but the production of the panels leads to some amount of 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,<ref>Anctil, Annick (June 2021). "Comparing the carbon footprint of monocrystalline silicon solar modules manufactured in China and the United States". 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC). pp. 1–3. doi:10.1109/PVSC43889.2021.9518632. ISBN 978-1-6654-1922-2. S2CID 237332457.</ref> but this is expected to fall as manufacturers use more clean electricity and recycled materials.<ref name=":3">"Solar power's potential limited unless "you do everything perfectly" says solar scientist". Dezeen. 21 September 2022. Retrieved 15 October 2022.</ref> Solar power carries an upfront cost to the environment via production with a carbon payback time of several years as of 2022^[update],<ref name=":3" /> but offers clean energy for the remainder of their 30-year lifetime.<ref>"Aging Gracefully: How NREL Is Extending the Lifetime of Solar Modules". www.nrel.gov. Retrieved 15 October 2022.</ref>

The life-cycle greenhouse-gas emissions of solar farms are less than 50 gram (g) per kilowatt-hour (kWh),<ref>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. 10 (4): 1083–1095. Bibcode:2022EneSE..10.1083Z. doi:10.1002/ese3.1100. ISSN 2050-0505. S2CID 247443046.</ref><ref>"Carbon Neutrality in the UNECE Region: Integrated Life-cycle Assessment of Electricity Sources" (PDF). p. 49.</ref><ref name=":0">"Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics" (PDF).</ref> but with battery storage could be up to 150 g/kWh.<ref>Mehedi, Tanveer Hassan; Gemechu, Eskinder; Kumar, Amit (15 May 2022). "Life cycle greenhouse gas emissions and energy footprints of utility-scale solar energy systems". Applied Energy. 314: 118918. Bibcode:2022ApEn..31418918M. doi:10.1016/j.apenergy.2022.118918. ISSN 0306-2619. S2CID 247726728.</ref> 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.<ref>"Life Cycle Assessment Harmonization". www.nrel.gov. Retrieved 4 December 2021.</ref> 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.<ref name=":0" />

Lifecycle surface power density of solar power varies a lot<ref name=":1" /> but averages about 7 W/m2, compared to about 240 for nuclear power and 480 for gas.<ref>Van Zalk, John; Behrens, Paul (1 December 2018). "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. 123: 83–91. doi:10.1016/j.enpol.2018.08.023. hdl:1887/64883. ISSN 0301-4215.</ref> 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.<ref name=":5" /> PV requires much larger amounts of land surface to produce the same nominal amount of energy as sources^[which?] 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.<ref>van de Ven, Dirk-Jan; Capellan-Peréz, Iñigo; Arto, Iñaki; Cazcarro, Ignacio; de Castro, Carlos; Patel, Pralit; Gonzalez-Eguino, Mikel (3 February 2021). "The potential land requirements and related land use change emissions of solar energy". Scientific Reports. 11 (1): 2907. Bibcode:2021NatSR..11.2907V. doi:10.1038/s41598-021-82042-5. ISSN 2045-2322. PMC 7859221. PMID 33536519.</ref> 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.<ref>Diab, Khaled. "There are grounds for concern about solar power". www.aljazeera.com. Retrieved 15 April 2021.</ref> However some countries, such as South Korea and Japan, use land for agriculture under PV,<ref>Staff, Carbon Brief (25 August 2022). "Factcheck: Is solar power a 'threat' to UK farmland?". Carbon Brief. Retrieved 15 September 2022.</ref><ref>Oda, Shoko (21 May 2022). "Electric farms in Japan are using solar power to grow profits and crops". The Japan Times. Retrieved 14 October 2022.</ref> or floating solar,<ref>Gerretsen, Isabelle. "The floating solar panels that track the Sun". www.bbc.com. Retrieved 29 November 2022.</ref> together with other low-carbon power sources.<ref>Pollard, Jim (29 May 2023). "Wind Power Body Plans to Provide a Third of Japan's Electricity". Asia Financial. Retrieved 31 May 2023.</ref><ref>"Clean power in South Korea" (PDF).</ref> Worldwide land use has minimal ecological impact.<ref>Dunnett, Sebastian; Holland, Robert A.; Taylor, Gail; Eigenbrod, Felix (8 February 2022). "Predicted wind and solar energy expansion has minimal overlap with multiple conservation priorities across global regions". Proceedings of the National Academy of Sciences. 119 (6). Bibcode:2022PNAS..11904764D. doi:10.1073/pnas.2104764119. ISSN 0027-8424. PMC 8832964. PMID 35101973.</ref> Land use can be reduced to the level of gas power by installing on buildings and other built up areas.<ref name=":1">"How does the land use of different electricity sources compare?". Our World in Data. Retrieved 3 November 2022.</ref>

Harmful materials are used in the production of solar panels, but in generally in small amounts.<ref>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". Science of the Total Environment. 754: 141989. Bibcode:2021ScTEn.754n1989R. doi:10.1016/j.scitotenv.2020.141989. ISSN 0048-9697. PMID 32920388. S2CID 221671774.</ref> As of 2022^[update] the environmental impact of perovskite is hard to estimate, but there is some concern that lead may become a problem.<ref name=":5">Urbina, Antonio (26 October 2022). "Sustainability of photovoltaic technologies in future net-zero emissions scenarios". Progress in Photovoltaics: Research and Applications. 31 (12): 1255–1269. doi:10.1002/pip.3642. ISSN 1062-7995. S2CID 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.</ref> 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.<ref>"Renewable revolution will drive demand for critical minerals". RenewEconomy. 5 May 2021. Retrieved 5 May 2021.</ref><ref>"Clean energy demand for critical minerals set to soar as the world pursues net zero goals - News". IEA. Retrieved 5 May 2021.</ref> More tellurium and indium may also be needed and recycling may help.<ref name=":5" />

As solar panels are sometimes replaced with more efficient panels, the second-hand panels are sometimes reused in developing countries, for example in Africa.<ref>"Used Solar Panels Are Powering the Developing World". Bloomberg.com. 25 August 2021. Retrieved 15 September 2022.</ref> Several countries have specific regulations for the recycling of solar panels.<ref>US EPA, OLEM (23 August 2021). "End-of-Life Solar Panels: Regulations and Management". www.epa.gov. Retrieved 15 September 2022.</ref><ref>"The Proposed Legal Framework On Responsibility Of Producers And..." www.roedl.com. Retrieved 15 September 2022.</ref><ref>Majewski, Peter; Al-shammari, Weam; Dudley, Michael; Jit, Joytishna; Lee, Sang-Heon; Myoung-Kug, Kim; Sung-Jim, Kim (1 February 2021). "Recycling of solar PV panels- product stewardship and regulatory approaches". Energy Policy. 149: 112062. doi:10.1016/j.enpol.2020.112062. ISSN 0301-4215. S2CID 230529644.</ref> Although maintenance cost is already low compared to other energy sources,<ref>Gürtürk, Mert (15 March 2019). "Economic feasibility of solar power plants based on PV module with levelized cost analysis". Energy. 171: 866–878. doi:10.1016/j.energy.2019.01.090. ISSN 0360-5442. S2CID 116733543.</ref> some academics have called for solar power systems to be designed to be more repairable.<ref>Cross, Jamie; Murray, Declan (1 October 2018). "The afterlives of solar power: Waste and repair off the grid in Kenya". Energy Research & Social Science. 44: 100–109. doi:10.1016/j.erss.2018.04.034. ISSN 2214-6296. S2CID 53058260.</ref><ref>Jang, Esther; Barela, Mary Claire; Johnson, Matt; Martinez, Philip; Festin, Cedric; Lynn, Margaret; Dionisio, Josephine; Heimerl, Kurtis (19 April 2018). "Crowdsourcing Rural Network Maintenance and Repair via Network Messaging". Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems. CHI '18. New York, NY, US: Association for Computing Machinery. pp. 1–12. doi:10.1145/3173574.3173641. ISBN 978-1-4503-5620-6. S2CID 4950067.</ref>

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.<ref>"Water consumption solution for efficient concentrated solar power | Research and Innovation". ec.europa.eu. Retrieved 4 December 2021.</ref>

Politics

Solar production cannot be cut off by geopolitics once installed, unlike oil and gas, which contributes to energy security.<ref>"Making solar a source of EU energy security | Think Tank | European Parliament". www.europarl.europa.eu. Retrieved 3 November 2022.</ref>

As of 2022^[update] over 40% of global polysilicon manufacturing capacity is in Xinjiang in China,<ref>Blunt, Katherine; Dvorak, Phred (9 August 2022). "WSJ News Exclusive | U.S. Solar Shipments Are Hit by Import Ban on China's Xinjiang Region". The Wall Street Journal. ISSN 0099-9660. Retrieved 8 September 2022.</ref> which raises concerns about human rights violations (Xinjiang internment camps) as well as supply chain dependency.<ref>"Fears over China's Muslim forced labor loom over EU solar power". Politico. 10 February 2021. Retrieved 15 April 2021.</ref>

References

Bibliography

Perlin, John (1999). From space to Earth: the story of solar electricity. Earthscan. p. 50. ISBN 978-0-937948-14-9.

External links

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

Template:Solar power by country

Lua error in mw.title.lua at line 318: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal').

Anonymous

Search