Portal:Renewable energy
 
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The Renewable Energy Portal
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Introduction Renewable energy (or green energy) is 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. 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...) Selected article -O'Shaughnessy Dam is a 430-foot (131 m) high concrete arch-gravity dam in Tuolumne County, California, United States. It impounds the Tuolumne River, forming the Hetch Hetchy Reservoir at the lower end of Hetch Hetchy Valley in Yosemite National Park, about 160 miles (260 km) east of San Francisco. The dam and reservoir are the source for the Hetch Hetchy Aqueduct, which provides water for over two million people in San Francisco and other municipalities of the west Bay Area. The dam is named for engineer Michael O'Shaughnessy, who oversaw its construction. Although San Francisco had sought Tuolumne River water as early as the 1890s, this project did not move forward until the disastrous earthquake and fire of 1906, which underscored the insufficiency of the existing water supply. The Hetch Hetchy Valley – then compared to Yosemite Valley for its scenic beauty – was chosen for its water quality and hydroelectric potential, but the location within the national park generated controversy. An act of Congress was required to circumvent federal protection of the Tuolumne River, with the reasoning that public land should be developed for the public benefit. Construction of the dam started in 1919 and was finished in 1923, with the first water delivered in 1934 after numerous delays. From 1935 to 1938, the dam was raised to increase its capacity for water supply and power generation. The dam, aqueduct and appurtenant hydroelectric systems are collectively known as the Hetch Hetchy Project. Deriving from a largely wild and pristine area of the Sierra Nevada, the Hetch Hetchy supply is some of the cleanest municipal water in the US, requiring only primary filtration and disinfection. (Full article...)Quotations -
– Lester R. Brown. PLAN B 3.0: Mobilizing to Save Civilization 2008, p. 215. Main topicsRenewable energy sourcesGeneralRenewable energy commercialization · Smart grid · Timeline of sustainable energy research 2020–present Renewable energy by countryList of countries by electricity production from renewable sources
WikiProjectsWikiProjects connected with renewable energy: Selected image - The world's largest solar energy dish at the Ben-Gurion National Solar Energy Center in Sde Boker, Israel. Selected biography -Jeremy Leggett is a British social entrepreneur and writer. He founded and was a board director of Solarcentury from 1997 to 2020, an international solar solutions company, and founded and was chair of SolarAid, a charity funded with 5% of Solarcentury's annual profits that helps solar-lighting entrepreneurs get started in Africa (2006–2020). SolarAid owns a retail brand SunnyMoney that was for a time Africa's top-seller of solar lighting, having sold well over a million solar lights, all profits recycled to the cause of eradicating the kerosene lantern from Africa. Leggett is winner of the first Hillary Laureate for International Leadership in Climate Change (2009), a Gothenburg Prize (2015), the first non-Dutch winner of a Royal Dutch Honorary Sustainability Award (2016), and has been described in the Observer as "Britain’s most respected green energy boss." He is the author of five books: "The Winning of The Carbon War", an account of what he sees as the "turnaround years" in the dawn of the global energy transition, 2013–2015, with an update edition spanning 2016–2017, "The Energy of Nations" (2013), "The Solar Century" (2009), "Half Gone" (2005) and "The Carbon War" (2000). He continues to write on his blog, and in occasional articles for national media. He lectured on short courses in business and society at the Universities of Cambridge (UK) and St Gallen (Switzerland). His vision is of a renaissance in civilisation aided or even triggered by renewable energy and its intrinsic social benefits. (Full article...)Did you know? -... 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. General images -The following are images from various renewable energy-related articles on Wikipedia.
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![Image 24Concentrated 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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