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...)
Waves are generated primarily by wind passing over the sea's surface and also by tidal forces, temperature variations, and other factors. As long as the waves propagate slower than the wind speed just above, energy is transferred from the wind to the waves. Air pressure differences between the windward and leeward sides of a wave crest and surface friction from the wind cause shear stress and wave growth.
Wave power as a descriptive term is different from tidal power, which seeks to primarily capture the energy of the current caused by the gravitational pull of the Sun and Moon. However, wave power and tidal power are not fundamentally distinct and have significant cross-over in technology and implementation. Other forces can create currents, including breaking waves, wind, the Coriolis effect, cabbeling, and temperature and salinity differences. (Full article...)
"Perhaps the quickest, easiest, and most profitable way to reduce electricity use worldwide — thus cutting carbon emissions — is simply to change light bulbs. Replacing the inefficient incandescent light bulbs that are still widely used today with new compact fluorescents (CFLs) can reduce electricity use by three fourths. The energy saved by replacing a 100-watt incandescent bulb with an equivalent CFL over its lifetime is sufficient to drive a Toyota Prius hybrid car from New York to San Francisco."
"Over its lifetime, each standard (13 watt) CFL will reduce electricity bills by roughly $30. And though a CFL may cost twice as much as an incandescent, it lasts 10 times as long. Since it uses less energy, it also means fewer CO2 emissions. Each one reduces energy use by the equivalent of 200 pounds of coal over its lifetime."
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...)
... that the Cragsidecountry house in Northumberland, England was the first house in the world to be lit using hydroelectric power? In 1870, water from one of the estate's lakes was used to drive a Siemensdynamo in what was the world's first hydroelectric power station. The resultant electricity was used to power an arc lamp installed in the Gallery in 1878.
Image 3Acceptance 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 17Concentrated 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 18Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
Image 19Enhanced 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 20Share of electricity production from wind, 2022 (from Wind power)
Image 21A panoramic view of the United Kingdom's Whitelee Wind Farm with Lochgoin Reservoir in the foreground. (from Wind power)
Image 23Wind 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 27Merowe 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 28Electricity production by source (from Wind power)
Image 29Yearly hydro generation by continent (from Hydroelectricity)
Image 30Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 31Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 32Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 33The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 34Cost development of solar PV modules per watt (from Solar energy)
Image 35The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 37Museum Hydroelectric power plant "Under the Town" in Užice, Serbia, built in 1900. (from Hydroelectricity)
Image 38Share of electricity production from hydropower, 2022 (from Hydroelectricity)
Image 39Electricity generation at Poihipi, New Zealand (from Geothermal energy)
Image 40Seasonal 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 44Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 45A 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 46Energy 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 57Distribution 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 59Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position (from Wind power)
Image 60The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
![Image 17Concentrated 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)](view_image.php?q=Portal:Renewable_energy&sq=MAxi Jazz&lang=en&file=File:Photo_of_the_Week-_Boosting_Solar_Technology_(8722948189).jpg)
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