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...)
The Renewable Energy Sources Act or EEG (German: Erneuerbare-Energien-Gesetz) is a series of German laws that originally provided a feed-in tariff (FIT) scheme to encourage the generation of renewable electricity. The EEG 2014 specified the transition to an auction system for most technologies which has been finished with the current version EEG 2017.
The EEG first came into force on 1April 2000 and has been modified several times since. The original legislation guaranteed a grid connection, preferential dispatch, and a government-set feed-in tariff for 20years, dependent on the technology and size of project. The scheme was funded by a surcharge on electricity consumers, with electricity-intensive manufacturers and the railways later being required to contribute as little as 0.05¢/kWh. For 2017, the unabated EEG surcharge is 6.88 ¢/kWh. In a study in 2011, the average retail price of electricity in Germany, among the highest in the world, stood at around 35 ¢/kWh.
The EEG was preceded by the Electricity Feed-in Act (1991) which entered into force on 1January 1991. This law initiated the first green electricity feed-in tariff scheme in the world. The original EEG is credited with a rapid uptake of wind power and photovoltaics (PV) and is regarded nationally and internationally as an innovative and successful energy policy measure. The act also covers biomass (including cogeneration), hydroelectricity, and geothermal energy. (Full article...)
... that because solar cookers use no fuel and they cost nothing to run, humanitarian organizations are promoting their use worldwide to help slow deforestation and desertification, caused by using wood as fuel for cooking ? Solar Cookers are a form of outdoor cooking and are often used in situations where minimal fuel consumption is important, or the danger of accidental fires is high.
Image 7The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 8Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 10Electricity generation at Poihipi, New Zealand (from Geothermal 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 12Distribution 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 17The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 18Solar water heaters facing the Sun to maximize gain (from Solar energy)
Image 25Seasonal 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 26A panoramic view of the United Kingdom's Whitelee Wind Farm with Lochgoin Reservoir in the foreground. (from Wind power)
Image 28Electricity production by source (from Wind power)
Image 29Wind 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 32Merowe 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 36Acceptance 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 37Enhanced 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 44Energy 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 45Museum Hydroelectric power plant "Under the Town" in Užice, Serbia, built in 1900. (from Hydroelectricity)
Image 48Concentrated 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)