Renewable energy (also called green energy) is energy made from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, and hydropower. Bioenergy and geothermal power are also significant in some countries. Some also consider nuclear power a renewable power source, although this is controversial, as nuclear energy requires mining uranium, a nonrenewable resource. Renewable energy installations can be large or small and are suited for both urban and rural areas. Renewable energy is often deployed together with further electrification. This has several benefits: electricity can move heat and vehicles efficiently and is clean at the point of consumption. Variable renewable energy sources are those that have a fluctuating nature, such as wind power and solar power. In contrast, controllable renewable energy sources include dammed hydroelectricity, bioenergy, or geothermal power.
Renewable energy systems have rapidly become more efficient and cheaper over the past 30 years. A large majority of worldwide newly installed worldwide electricity capacity is now renewable. Renewable energy sources, such as solar and wind power, have seen significant cost reductions over the past decade, making them more competitive with traditional fossil fuels. In some geographic localities, photovoltaic solar or onshore wind is the cheapest new-build electricity. From 2011 to 2021, renewable energy grew from 20% to 28% of the global electricity supply. Power from the sun and wind accounted for most of this increase, growing from a combined 2% to 10%. Use of fossil energy shrank from 68% to 62%. In 2024, renewables accounted for over 30% of global electricity generation and are projected to reach over 45% by 2030. Many countries already have renewables contributing more than 20% of their total energy supply, with some generating over half or even all their electricity from renewable sources.
The main motivation to use renewable energy instead of fossil fuels is to slow and eventually stop climate change, which is mostly caused by their greenhouse gas emissions. In general, renewable energy sources pollute much less than fossil fuels. The International Energy Agency estimates that to achieve net zero emissions by 2050, 90% of global electricity will need to be generated by renewables. Renewables also cause much less air pollution than fossil fuels, improving public health, and are less noisy.
The deployment of renewable energy still faces obstacles, especially fossil fuel subsidies, lobbying by incumbent power providers, and local opposition to the use of land for renewable installations. Like all mining, the extraction of minerals required for many renewable energy technologies also results in environmental damage. In addition, although most renewable energy sources are sustainable, some are not. (Full article...)
A map of major renewable energy resources in the contiguous United States.
According to data from the US Energy Information Administration, renewable energy accounted for 8.4% of total primary energy production and 21% of total utility-scale electricity generation in the United States in 2022.
Since 2019, wind power has been the largest producer of renewable electricity in the country. Wind power generated 434 terawatt-hours of electricity in 2022, which accounted for 10% of the nation's electricity and 48% of renewable generation. By January 2023, the United States nameplate generating capacity for wind power was 141.3 gigawatts (GW). Texas remained firmly established as the leader in wind power deployment, followed by Iowa and Oklahoma as of the first quarter of 2023.
Hydroelectric power is the second-largest producer of renewable electricity in the country, generating around 6.2% of the nation's electricity in 2022 as well as 29% of renewable generation.
The United States is the fourth largest producer of hydroelectricity in the world after China, Canada and Brazil. (Full article...)
"Perhaps the quickest, easiest, and most profitable way to reduce electricity use worldwide — thus cutting carbon emissions — is simply to change light bulbs. Replacing the inefficient incandescent light bulbs that are still widely used today with new compact fluorescents (CFLs) can reduce electricity use by three fourths. The energy saved by replacing a 100-watt incandescent bulb with an equivalent CFL over its lifetime is sufficient to drive a Toyota Prius hybrid car from New York to San Francisco."
"Over its lifetime, each standard (13 watt) CFL will reduce electricity bills by roughly $30. And though a CFL may cost twice as much as an incandescent, it lasts 10 times as long. Since it uses less energy, it also means fewer CO2 emissions. Each one reduces energy use by the equivalent of 200 pounds of coal over its lifetime."
Chu served as U.S. Secretary of Energy under the administration of President Barack Obama from 2009 to 2013. At the time of his appointment as Energy Secretary, Chu was a professor of physics and molecular and cellular biology at the University of California, Berkeley, and the director of the Lawrence Berkeley National Laboratory, where his research was concerned primarily with the study of biological systems at the single molecule level. Chu resigned as energy secretary on April 22, 2013. He returned to Stanford as Professor of Physics and Professor of Molecular & Cellular Physiology. (Full article...)
... that Selling Solar: The Diffusion of Renewable Energy in Emerging Markets, a 2009 Earthscan book by Damian Miller, argues that in order to solve the climate crisis, the world must immediately and dramatically accelerate the commercialization of renewable energy technology ? This needs to happen in the industrialized world, as well as in the emerging markets of the developing world where most future GHG emissions will occur.
Image 7Enhanced geothermal system 1:Reservoir 2:Pump house 3:Heat exchanger 4:Turbine hall 5:Production well 6:Injection well 7:Hot water to district heating 8:Porous sediments 9:Observation well 10:Crystalline bedrock (from Geothermal energy)
Image 8Distribution of wind speed (red) and energy (blue) for all of 2002 at the Lee Ranch facility in Colorado. The histogram shows measured data, while the curve is the Rayleigh model distribution for the same average wind speed. (from Wind power)
Image 9Hydro generation by country, 2021 (from Hydroelectricity)
Image 10Geothermal power station in the Philippines (from Geothermal energy)
Image 15Concentrated solar panels are getting a power boost. Pacific Northwest National Laboratory (PNNL) will be testing a new concentrated solar power system – one that can help natural gas power plants reduce their fuel usage by up to 20 percent.[needs update] (from Solar energy)
Image 16Krafla Geothermal Station in northeast Iceland (from Geothermal energy)
Image 20A panoramic view of the United Kingdom's Whitelee Wind Farm with Lochgoin Reservoir in the foreground. (from Wind power)
Image 21Collisions with wind turbines are a minor source of bird mortality compared to other human causes (from Wind power)
Image 22Merowe Dam in Sudan. Hydroelectric power stations that use dams submerge large areas of land due to the requirement of a reservoir. These changes to land color or albedo, alongside certain projects that concurrently submerge rainforests, can in these specific cases result in the global warming impact, or equivalent life-cycle greenhouse gases of hydroelectricity projects, to potentially exceed that of coal power stations. (from Hydroelectricity)
Image 25Seasonal cycle of capacity factors for wind and photovoltaics in Europe under idealized assumptions. The figure illustrates the balancing effects of wind and solar energy at the seasonal scale (Kaspar et al., 2019). (from Wind power)
Image 28Cost development of solar PV modules per watt (from Solar energy)
Image 29Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 30Wind turbines such as these, in Cumbria, England, have been opposed for a number of reasons, including aesthetics, by some sectors of the population. (from Wind power)
Image 31Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 33Solar water heaters facing the Sun to maximize gain (from Solar energy)
Image 34Energy from wind, sunlight or other renewable energy is converted to potential energy for storage in devices such as electric batteries or higher-elevation water reservoirs. The stored potential energy is later converted to electricity that is added to the power grid, even when the original energy source is not available. (from Wind power)
Image 35Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position (from Wind power)
Image 36Electricity generation at Ohaaki, New Zealand (from Geothermal energy)
Image 37Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)
Image 42Electricity generation at Poihipi, New Zealand (from Geothermal energy)
Image 43Global map of wind power density potential (from Wind power)
Image 44Yearly hydro generation by continent (from Hydroelectricity)
Image 45The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 51Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
Image 52Museum Hydroelectric power plant "Under the Town" in Užice, Serbia, built in 1900 (from Hydroelectricity)
Image 53The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 54A turbine blade convoy passing through Edenfield in the U.K. (2008). Even longer 2-piece blades are now manufactured, and then assembled on-site to reduce difficulties in transportation. (from Wind power)
Image 55Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 57Acceptance 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). (from Wind power)
![Image 15Concentrated solar panels are getting a power boost. Pacific Northwest National Laboratory (PNNL) will be testing a new concentrated solar power system – one that can help natural gas power plants reduce their fuel usage by up to 20 percent.[needs update] (from Solar energy)](/wiki/File:Photo_of_the_Week-_Boosting_Solar_Technology_(8722948189).jpg?lang=en)
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