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...)
A photovoltaic power station, also known as a solar park, solar farm, or solar power plant, is a large-scale
grid-connected photovoltaic power system (PV system) designed for the supply of
merchant power. They are different from most building-mounted and other decentralized
solar power because they supply power at the
utility level, rather than to a local user or users. Utility-scale solar is sometimes used to describe this type of project.
This approach differs from
concentrated solar power, the other major large-scale solar generation technology, which uses heat to drive a variety of conventional generator systems. Both approaches have their own advantages and disadvantages, but to date, for a variety of reasons,
photovoltaic technology has seen much wider use. , about 97% of utility-scale solar power capacity was PV.
In some countries, the
nameplate capacity of photovoltaic power stations is rated in
megawatt-peak (MWp), which refers to the solar array's theoretical maximum
DC power output. In other countries, the manufacturer states the surface and the efficiency. However, Canada, Japan, Spain, and the United States often specify using the converted lower nominal power output in
MWAC, a measure more directly comparable to other forms of power generation. Most solar parks are developed at a scale of at least 1 MWp. As of 2018, the
world's largest operating photovoltaic power stations surpassed 1
gigawatt. At the end of 2019, about 9,000 solar farms were larger than 4 MWAC (utility scale), with a combined capacity of over 220 GWAC. (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.
Image 5Acceptance 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 6The
Warwick Castle water-powered generator house, used for the generation of electricity for the castle from 1894 until 1940 (from Hydroelectricity)
Image 7Parabolic dish produces steam for cooking, in
Auroville, India. (from Solar energy)
Image 8Onshore wind cost per kilowatt-hour between 1983 and 2017 (from Wind power)
Image 10The
Hoover Dam in the United States is a large conventional dammed-hydro facility, with an installed capacity of 2,080
MW. (from Hydroelectricity)
Image 11Seasonal 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 12Hydro generation by country, 2021 (from Hydroelectricity)
Image 14Global geothermal electric capacity. Upper red line is installed capacity; lower green line is realized production. (from Geothermal energy)
Image 15Wind 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 20A 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 40Distribution 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 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 43Global map of wind speed at 100 meters on land and around coasts. (from Wind power)
Image 55Merowe 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 56Geothermal power station in the Philippines (from Geothermal energy)
Image 58Museum Hydroelectric power plant "Under the Town" in
Užice,
Serbia, built in 1900. (from Hydroelectricity)
Image 59Enhanced 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)
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![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)](/info/en/?search=File:Photo_of_the_Week-_Boosting_Solar_Technology_(8722948189).jpg)
