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 dam was built by the Alaska-Gastineau Mining Company to meet the electrical energy needs for mining operations. The dam continues to be fully functional for hydroelectric generation, as one of the drinking water sources to Juneau city and for aquaculture and fishing. When built, adoption of the constant arch design for the dam reduced costs by 20% because less concrete was needed to construct the dam. Of the two hydroelectric power stations built at the initial stage (one at the upper level and the other at the lower level) – the latter one is still in use after a new powerhouse was built adjoining the old one – it produces 10% of the energy needs of Juneau city. When built, the dam and its two power plants were considered engineering wonders. Both are operated and maintained by the Alaska Electric Light & Power (AEL&P). (Full article...)
"Today’s green buildings use some 30% less energy than their comparably sized nongreen counterparts (some save much more), and they’re generally brighter, healthier, and more aesthetically pleasing. Often built with little or no additional up-front cost, green offices, for instance, pay back not only in energy savings but also in greater employee retention, attendance, and productivity." – Ron Pernick and Clint Wilder. The Clean Tech Revolution, 2007, p. 21.
Denis Allen Hayes (born August 29, 1944) is an environmental advocate and an advocate for solar power. He rose to prominence in 1970 as the coordinator for the first Earth Day.
... 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 5Wind 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 6Greenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. (from Solar energy)
Image 7Merowe 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 8Global map of wind power density potential (from Wind power)
Image 9Cost development of solar PV modules per watt (from Solar energy)
Image 14The Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080 MW. (from Hydroelectricity)
Image 16Share of electricity production from wind, 2022 (from Wind power)
Image 17Share of electricity production from hydropower, 2022 (from Hydroelectricity)
Image 18Concentrated 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 32Seasonal 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 45Enhanced 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 46A 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 47Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 48Distribution 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 51Parabolic dish produces steam for cooking, in Auroville, India. (from Solar energy)
Image 52The Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 53Acceptance 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 54Museum Hydroelectric power plant "Under the Town" in Užice, Serbia, built in 1900. (from Hydroelectricity)
![Image 18Concentrated 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)](https://naturehabitats.org/knowledge-base/vernonia/?rdp_we_resource=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FFile%3APhoto_of_the_Week-_Boosting_Solar_Technology_%288722948189%29.jpg)
Recent Comments