Renewable energy (or green energy) will be energy 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. 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 2022, renewables accounted for 30% of global electricity generation and are projected to reach over 42% by 2028. 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 replace fossil fuels with renewable energy sources is to slow and eventually stop climate change, which is widely agreed to be caused mostly by greenhouse gas emissions. In general, renewable energy sources cause much lower emissions than fossil fuels. The International Energy Agency estimates that to achieve net zero emissions by 2050, 90% of global electricity generation will need to be produced from renewable sources. 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...)
Renewable energy progress in the European Union (EU) is driven by the European Commission's 2023 revision of the Renewable Energy Directive, which raises the EU's binding renewable energy target for 2030 to at least 42.5%, up from the previous target of 32%. Effective since November 20, 2023, across all EU countries, this directive aligns with broader climate objectives, including reducing greenhouse gas emissions by at least 55% by 2030 and achieving climate neutrality by 2050. Additionally, the Energy 2020 strategy exceeded its goals, with the EU achieving a 22.1% share of renewable energy in 2020, surpassing the 20% target.
The main source of renewable energy in 2019 was biomass (57.4% of gross energy consumption). In particular, wood is the leading source of renewable energy in Europe, far ahead of solar and wind. In 2020, renewables provided 23.1% of gross energy consumption in heating and cooling. In electricity, renewables accounted for 37.5% of gross energy consumption, led by wind (36%) and hydro-power (33%), followed by solar (14%), solid biofuels (8%) and other renewable sources (8%). In transport, the share of renewable energy used reached 10.2%.
Renewable electricity generation reached 50% of total EU electricity in the first half of 2024.
In 2022, Sweden led among EU nations, with nearly two-thirds (66.0%) of its gross final energy consumption derived from renewable sources, followed by Finland (47.9%), Latvia (43.3%), Denmark (41.6%), and Estonia (38.5%). Conversely, the EU members reporting the lowest renewable energy proportions included Ireland (13.1%), Malta (13.4%), Belgium (13.8%), and Luxembourg (14.4%), with 17 out of the 27 falling below the EU average of 23.0%. (Full article...)
"Our dependence on fossil fuels amounts to global pyromania, and the only fire extinguisher we have at our disposal is renewable energy." – Hermann Scheer.
"There is one forecast of which you can already be sure: someday renewable energy will be the only way for people to satisfy their energy needs. Because of the physical, ecological and (therefore) social limits to nuclear and fossil energy use, ultimately nobody will be able to circumvent renewable energy as the solution, even if it turns out to be everybody’s last remaining choice. The question keeping everyone in suspense, however, is whether we shall succeed in making this radical change of energy platforms happen early enough to spare the world irreversible ecological mutilation and political and economic catastrophe." – Hermann Scheer, Energy Autonomy: The Economic, Social and Technological Case for Renewable Energy (2006)
The Tataragi Dam serving the Okutataragi Hydroelectric Power Station is one of the largestpumped-storage power stations in the world, and the largest in Japan.
Image 5A 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 9Electricity production by source (from Wind power)
Image 10Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 11Energy 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 12Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 17Enhanced 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 33The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 34Acceptance 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 35Hydro generation by country, 2021 (from Hydroelectricity)
Image 37The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 38Concentrated 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 39Installed geothermal energy capacity, 2022 (from Geothermal energy)
Image 40Yearly hydro generation by continent (from Hydroelectricity)
Image 41Greenhouse gas emissions per energy source. Wind energy is one of the sources with the least greenhouse gas emissions. (from Wind power)
Image 42Distribution 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 49Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 50Merowe 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 51Wind 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 52Seasonal 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 55Geothermal power station in the Philippines (from Geothermal energy)
Image 56The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)