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...)
Photovoltaics (PV) were initially solely used as a source of electricity for small and medium-sized applications, from the calculator powered by a single solar cell to remote homes powered by an off-grid rooftop PV system. Commercial concentrated solar power plants were first developed in the 1980s. Since then, as the cost of solar panels has fallen, grid-connected solar PV systems' capacity and production has doubled about every three years. Three-quarters of new generation capacity is solar, with both millions of rooftop installations and gigawatt-scale photovoltaic power stations continuing to be built.
"People do not want electricity or oil ... but rather comfortable rooms, light, vehicular motion, food, tables, and other real things."
"There exists today a body of energy technologies that have certain specific features in common and that offer great technical, economic, and political attractions ... 'soft' energy technologies [which are] flexible, resilient, sustainable, and benign. They rely on renewable energy flows that are always there whether we use them of not, such as sun and wind and vegetation."
"Soft technologies' matching of energy quality to end-use needs virtually eliminates the costs and losses of secondary energy conversion, [and] the appropriate scale of soft technologies can virtually eliminate the costs and losses of energy distribution."
– Amory Lovins, Soft Energy Paths, 1977, pp. 38–40.
Hans-Josef Fell (born 7 January 1952) was a member of the German Parliamentary Group Alliance 90/ the Greens from 1998 to 2013. He served as spokesman on energy for the Alliance 90/The Greens parliamentary group, a member of the Environmental Protection Committee, substitute member of the Committee on Economics and Technology and substitute member of the Defence Committee. Together with Hermann Scheer, he authored the 2000 draft of the Renewable Energy Sources Act, establishing the foundation for the technology developments in photovoltaic, biogas, wind power and geothermal energy in Germany. Fell is founder and president of the Energy Watch Group and an internationally renowned energy and climate change advisor, author and speaker. (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 16The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 17Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 18Solar water heaters facing the Sun to maximize gain (from Solar energy)
Image 23Electricity production by source (from Wind power)
Image 24Global map of wind power density potential (from Wind power)
Image 25The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 27Seasonal 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 28Merowe 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 35Distribution 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 40Geothermal power station in the Philippines (from Geothermal energy)
Image 41A panoramic view of the United Kingdom's Whitelee Wind Farm with Lochgoin Reservoir in the foreground. (from Wind power)
Image 42Concentrated 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 43Wind turbine floating off France (from Wind power)
Image 45Wind 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 46Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)
Image 47Share of electricity production from hydropower, 2022 (from Hydroelectricity)
Image 49Electricity generation at Ohaaki, New Zealand (from Geothermal energy)
Image 50Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 51Electricity generation at Poihipi, New Zealand (from Geothermal energy)
Image 52A 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 53The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BCE (from Geothermal energy)
Image 56Acceptance 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 57Krafla Geothermal Station in northeast Iceland (from Geothermal energy)