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 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 renewables 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. For example, some biomass sources are unsustainable at current rates of exploitation. (Full article...)
"We need to push ourselves to make as many reductions as possible in our own energy use first.. and that takes time. But we must do this quickly.. the climate will not wait for us." -Rupert Murdoch
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.
Denis Allen Hayes (born August 29, 1944) is an environmental advocate and an advocate for solar power. He rose to prominence in 1970 as the coordinator for the first Earth Day.
... that the first recorded instance of solar distillation was by 16th century Arab alchemists? A large-scale solar distillation project was first constructed in 1872 in Chile a mining town of Las Salinas. The plant, which had a solar collection area of 4,700 m², could produce up to 22,700 L per day and operated for 40 years. Individual still designs include single-slope, double-slope (or greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect. These stills can operate in passive, active, or hybrid modes. Double-slope stills are the most economical for decentralized domestic purposes, while active multiple effect units are more suitable for large-scale applications.
Image 6The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 7The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 8Electricity generation at Poihipi, New Zealand (from Geothermal energy)
Image 9Wind 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 10Cost development of solar PV modules per watt (from Solar energy)
Image 11A 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 12Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 14Distribution 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 27Wind turbine floating off France (from Wind power)
Image 28The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 30Solar water heaters facing the Sun to maximize gain (from Solar energy)
Image 31Concentrated 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 39Share of electricity production from hydropower, 2022 (from Hydroelectricity)
Image 40Electricity generation at Ohaaki, New Zealand (from Geothermal energy)
Image 41Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
Image 42Greenhouse gas emissions per energy source. Wind energy is one of the sources with the least greenhouse gas emissions. (from Wind power)
Image 43Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position (from Wind power)
Image 44Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 45Enhanced 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 46Acceptance 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 47Installed geothermal energy capacity, 2022 (from Geothermal energy)
Image 48Energy 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 49A panoramic view of the United Kingdom's Whitelee Wind Farm with Lochgoin Reservoir in the foreground. (from Wind power)
Image 50Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 51Global map of wind speed at 100 meters on land and around coasts. (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 53Merowe 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 54Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)