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...)
As of 2019, worldwide geothermal power capacity amounts to 15.4 gigawatts (GW), of which 23.9% (3.68 GW) are installed in the United States. International markets grew at an average annual rate of 5 percent over the three years to 2015, and global geothermal power capacity is expected to reach 14.5–17.6 GW by 2020. Based on current geologic knowledge and technology the Geothermal Energy Association (GEA) publicly discloses, the GEA estimates that only 6.9% of total global potential has been tapped so far, while the IPCC reported geothermal power potential to be in the range of 35 GW to 2 TW. Countries generating more than 15 percent of their electricity from geothermal sources include El Salvador, Kenya, the Philippines, Iceland, New Zealand, and Costa Rica. Indonesia has an estimated potential of 29 GW of geothermal energy resources, the largest in the world; in 2017, its installed capacity was 1.8 GW.
"First, once the renewable infrastructure is built, the fuel is free forever. Unlike carbon-based fuels, the wind and the sun and the earth itself provide fuel that is free, in amounts that are effectively limitless."
"Second, while fossil fuel technologies are more mature, renewable energy technologies are being rapidly improved. So innovation and ingenuity give us the ability to constantly increase the efficiency of renewable energy and continually reduce its cost."
"Third, once the world makes a clear commitment to shifting toward renewable energy, the volume of production will itself sharply reduce the cost of each windmill and each solar panel, while adding yet more incentives for additional research and development to further speed up the innovation process."
A member of the wealthy South African Musk family, Musk was born in Pretoria and briefly attended the University of Pretoria before immigrating to Canada at age 18, acquiring citizenship through his Canadian-born mother. Two years later, he matriculated at Queen's University at Kingston in Canada. Musk later transferred to the University of Pennsylvania and received bachelor's degrees in economics and physics. He moved to California in 1995 to attend Stanford University, but dropped out after two days and, with his brother Kimbal, co-founded online city guide software company Zip2. The startup was acquired by Compaq for $307 million in 1999. That same year, Musk co-founded X.com, a direct bank. X.com merged with Confinity in 2000 to form PayPal. In October 2002, eBay acquired PayPal for $1.5 billion. Using $100 million of the money he made from the sale of PayPal, Musk founded SpaceX, a spaceflight services company, in 2002. (Full article...)
... that the Exelon Pavilions, a set of four solar energy generating structures in Millennium Park of Chicago, provide sufficient energy to power the equivalent of 14 star-rated energy-efficient houses in Chicago ? In addition to producing energy, three of the four pavilions provide access to the park's below ground parking garages and the fourth serves as the park's welcoming center. Exelon, a company that generates the electricity transmitted by its subsidiary Commonwealth Edison, donated approximately $5–6 million for the Pavilions.
Image 11Wind turbine floating off France (from Wind power)
Image 12Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 13Merowe 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 14Museum Hydroelectric power plant "Under the Town" in Užice, Serbia, built in 1900. (from Hydroelectricity)
Image 16Greenhouse gas emissions per energy source. Wind energy is one of the sources with the least greenhouse gas emissions. (from Wind power)
Image 17Distribution 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 18A 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 22Acceptance 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 29Concentrated 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 30Share of electricity production from wind, 2022 (from Wind power)
Image 41The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 46The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 47Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 51Electricity generation at Poihipi, New Zealand (from Geothermal energy)
Image 52Yearly hydro generation by continent (from Hydroelectricity)
Image 53Seasonal 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 54Hydro generation by country, 2021 (from Hydroelectricity)
Image 55Enhanced 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 56Electricity generation at Wairakei, New Zealand (from Geothermal energy)
Image 57Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)
Image 58Wind 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)