From 2011 to 2021, renewable energy grew from 20% to 28% of global electricity supply. Use of fossil energy shrank from 68% to 62%, and nuclear from 12% to 10%. The share of hydropower decreased from 16% to 15% while power from sun and wind increased from 2% to 10%. Biomass and geothermal energy grew from 2% to 3%.
Renewable energy systems are rapidly becoming more efficient and cheaper. As a result, their share of the global energy consumption is increasing. A large majority of worldwide newly installed electricity capacity is now renewable. In most countries, photovoltaic solar or onshore wind are the cheapest new-build electricity. Renewable energy can help reduce energy poverty in rural and remote areas of developing countries, where lack of energy access is often hindering economic development.
Many countries around the world already have renewable energy contributing more than 20% of their total energy supply. Some countries generate over half their electricity from renewables. A few countries generate all their electricity from renewable energy. National renewable energy markets are projected to continue to grow strongly in the 2020s and beyond. According to the IEA, to achieve net zero emissions by 2050, 90% of global electricity generation will need to be produced from renewable sources.
Renewable energy resources exist all over the world. This is in contrast to fossil fuels resources which are concentrated in a limited number of countries. However, the deployment of renewable energy is being hindered by massive fossil fuel subsidies. In 2022 the International Energy Agency requested all countries to reduce their policy, regulatory, permitting and financing obstacles for renewables. This would increase the chances of the world reaching net zero carbon emissions by 2050.
There are ongoing debates around the renewable energy topic. For example, whether nuclear power should be grouped under the renewable energy category or not. There are also debates around geopolitics, the metal and mineral extraction needed for solar panels and batteries, possible installations in conservation areas and the need to recycle solar panels. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are unsustainable at current rates of exploitation.
"The variability of sun, wind and so on, turns out to be a non-problem if you do several sensible things. One is to diversify your renewables by technology, so that weather conditions bad for one kind are good for another. Second, you diversify by site so they're not all subject to the same weather pattern at the same time because they're in the same place. Third, you use standard weather forecasting techniques to forecast wind, sun and rain, and of course hydro operators do this right now. Fourth, you integrate all your resources — supply side and demand side..." – Amory Lovins
"Because the wind blows during stormy conditions when the sun does not shine and the sun often shines on calm days with little wind, combining wind and solar can go a long way toward meeting demand, especially when geothermal provides a steady base and hydroelectric can be called on to fill in the gaps". – Mark Z. Jacobson and Mark A. Delucchi. Scientific American, November 2009, p. 43.
John Ingle Yellott (October 25, 1908 – December 30, 1986) was an American engineer recognized as a pioneer in passive solar energy, and an inventor with many patents to his credit. In his honor the American Society of Mechanical Engineers (ASME) Solar Division confers a biannual "John I. Yellott Award" which "recognizes ASME members who have demonstrated sustained leadership within the Solar Energy Division, have a reputation for performing high-quality solar energy research and have made significant contributions to solar engineering through education, state or federal government service or in the private sector." (Full article...)
Image 2Seasonal 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 3The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 4Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 9Hydro generation by country, 2021 (from Hydroelectricity)
Image 10Wind 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 11Solar water heaters facing the Sun to maximize gain (from Solar energy)
Image 12Geothermal power station in the Philippines (from Geothermal energy)
Image 13Electricity generation at Ohaaki, New Zealand (from Geothermal energy)
Image 14Greenhouse gas emissions per energy source. Wind energy is one of the sources with the least greenhouse gas emissions. (from Wind power)
Image 15Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 16Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
Image 17Global map of wind power density potential (from Wind power)
Image 18Merowe 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 19Share of electricity production from hydropower, 2022 (from Hydroelectricity)
Image 21Distribution 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 27Concentrated 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 40Enhanced 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 41Electricity production by source (from Wind power)
Image 42Krafla Geothermal Station in northeast Iceland (from Geothermal energy)
Image 43A 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 44The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 45The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 46Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)
Image 47Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position (from Wind power)
Image 51Acceptance 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 52Share of electricity production from wind, 2022 (from Wind power)
Image 53Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 54Installed geothermal energy capacity, 2022 (from Geothermal energy)
Image 55Yearly hydro generation by continent (from Hydroelectricity)
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![Image 27Concentrated 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)](https://en.wikipedia.org/wiki/File:Photo_of_the_Week-_Boosting_Solar_Technology_(8722948189).jpg)
