Solar power is clean, green, inexpensive, and renewable power that is produced when sunlight strikes human-made solar cells and is subsequently converted into electrical energy. Solar power is effectively infinite in supply and can be generated at any point at which sunlight reaches the ground in every country on Earth. Solar energy also prevents the negative impacts of fossil fuels, such as greenhouse gas emissions from coal consumption.
The use of solar power is increasing worldwide. By the end of 2021, photovoltaic solar arrays provided an estimated 5% of the world's electricity—a small, but growing percentage. Experts estimate that the countries of the world installed between 133 and 175 gigawatts (GW) of new solar power in 2021, and are expected to install another 200 GW by the end of 2022. Solar also has massive potential to expand further. According to a 2020 report by the World Bank, nearly every country in the world has the right combination of geographic conditions, weather, and sunlight to generate all the electricity it needs—and more—using solar power facilities placed within its own borders.
Note: If it were a single country, the European Union (EU) would have the second-highest solar capacity in the world at 178,700 MW
With 95,209 MW of solar power online and more on the way, the U.S. currently has enough solar power capacity to power 18 million households. A report from the National Renewable Energy Laboratory determined that solar panels covering a collective area of 22,000 square miles—roughly the area of Lake Michigan, or just over six tenths of a percent (.6%) of the country's total land area, could provide enough electricity to power the entire United States.
Solar energy is typically harnessed using either photovoltaic (PV) or concentrated solar power (CSP) systems. Photovoltaic systems are by far the more common and versatile of the two. Photovoltaic systems generate electricity directly from sunlight via solar cells: When solar radiation (sunlight) strikes a photovoltaic solar cell, the light's photons ionize semiconductor material (usually silicon) in the solar cell, which causes electrons to break free of their atomic bonds and creates an electrical current that can then be either directed or stored in a battery.
Solar cells absorb specific wavelengths of light. Other wavelengths are either reflected, too weak to be efficiently converted (infrared), or create heat instead of electricity (ultraviolet). However, solar cell technology continues to improve, increasing the efficiency of the conversion process.
The second-most-common method of harnessing solar energy is the concentrated solar power (CSP) installation. CSP plants produce electricity indirectly using devices known as solar thermal collectors, which focus solar energy to heat water, which then becomes steam and moves a turbine whose motion generates electricity. Globally, current CSP installations generate only a fraction as much energy (6,387 MW) as photovoltaic systems (843,086 MW),
Worldwide usage of solar energy varies greatly by country, with the top 10 countries representing approximately 74% of the photovoltaic market. As of 2021, China has the largest solar energy capacity in the world at 306,973 megawatts (MW), which produces roughly 4.8%-6% of the country’s total energy consumption. It is followed by the United States at 95,209 MW and Japan at 74,191 MW.
However, total capacity is only one way to view solar production. Another method is to examine solar penetration—that is, the percentage of each country's total energy consumption that comes from its solar installations.
The origin of modern solar cells can be traced back to 1954, when Bell Labs introduced the first PV device capable of producing a usable amount of electricity. The energy crisis of the 1970s resulted in a groundswell of interest in using solar energy to produce electricity for homes and businesses. At the time, the high manufacturing costs of solar cells (a relatively new technology) made large-scale applications impractical. Over time, the cost of photovoltaic cells has dropped dramatically, including a decrease of more than 59% over the past decade, making solar affordable for not only utilities and corporate offices, but for private homes as well.
Here are the 10 countries with the most solar power capacity:
As a percentage of its total power use, Australia uses the most solar power, 15.5% of its total energy consumption.