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 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 most countries, photovoltaic solar or onshore wind are the cheapest new-build electricity. From 2011 to 2021, renewable energy grew from 20% to 28% of 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...)
The Renewable Energy Sources Act or EEG (German: Erneuerbare-Energien-Gesetz) is a series of German laws that originally provided a feed-in tariff (FIT) scheme to encourage the generation of renewable electricity. The EEG 2014 specified the transition to an auction system for most technologies which has been finished with the current version EEG 2017.
The EEG first came into force on 1April 2000 and has been modified several times since. The original legislation guaranteed a grid connection, preferential dispatch, and a government-set feed-in tariff for 20years, dependent on the technology and size of project. The scheme was funded by a surcharge on electricity consumers, with electricity-intensive manufacturers and the railways later being required to contribute as little as 0.05¢/kWh. For 2017, the unabated EEG surcharge is 6.88 ¢/kWh. In a study in 2011, the average retail price of electricity in Germany, among the highest in the world, stood at around 35 ¢/kWh.
The EEG was preceded by the Electricity Feed-in Act (1991) which entered into force on 1January 1991. This law initiated the first green electricity feed-in tariff scheme in the world. The original EEG is credited with a rapid uptake of wind power and photovoltaics (PV) and is regarded nationally and internationally as an innovative and successful energy policy measure. The act also covers biomass (including cogeneration), hydroelectricity, and geothermal energy. (Full article...)
"Wind power is widely seen as the source of renewable energy with the best chance of competing with fossil-fuel power stations in the near term." – The Economist Technology Quarterly, 12 June 2010, p. 12.
"In 2009, a total of 38,103 MW of new wind installations were recorded, with the total installed global wind power capacity now standing at 160 GW. This represents an increase in cumulative installations of 31%, and a 35% rise in the rate of annual installations. This was the fifth year in a row with record installations, albeit a slightly lower rate compared with the 42% achieved in 2008." – BTM Wind Market ReportRenewable Energy World, 20 July 2010.
Scheer believed that the continuation of current patterns of energy supply and use would be environmentally, socially, economically, and politically damaging, with renewable energy being the only realistic alternative. Scheer had concluded that it is technically and environmentally feasible to harness enough solar radiation to achieve a total replacement of the foclear (fossil/nuclear) energy system by a global renewable energy economy. The main obstacle to such a change is seen to be political, not technical or economic. In 1999 he was one of the initiators of the German feed-in tariffs that were the major source of the rise of renewable energies in Germany during the following years. (Full article...)
The following are images from various renewable energy-related articles on Wikipedia.
Image 1The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 2Wind 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 4Concentrated 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 5Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 6The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 7A 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 8Acceptance 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 9Distribution 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 10Share of electricity production from hydropower, 2024 (from Hydroelectricity)
Image 11Installed geothermal energy capacity, 2023 (from Geothermal energy)
Image 26Yearly hydro generation by continent (from Hydroelectricity)
Image 27Energy 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 33Merowe 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 35Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 36The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 37Greenhouse gas emissions per energy source. Wind energy is one of the sources with the least greenhouse gas emissions. (from Wind power)
Image 43Enhanced 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 54Seasonal 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 55Share of electricity production from wind, 2024 (from Wind power)
Image 56Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
![Image 4Concentrated 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)
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