Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.8% and are growing rapidly.
Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 282,482 megawatts (MW) at the end of 2012, and is widely used in Europe, Asia, and the United States. At the end of 2013 the photovoltaic (PV) capacity worldwide was 138,900 MW, and PV power stations are popular in Germany and Italy and growing rapidly in China. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel. Ethanol fuel is also widely available in the USA.
While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development. As of 2011, small solar PV systems provide electricity to a few million households, and micro-hydro configured into mini-grids serves many more. Over 44 million households use biogas made in household-scale digesters for lighting and/or cooking, and more than 166 million households rely on a new generation of more-efficient biomass cookstoves. United Nation's Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity.
Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization. New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors. According to a 2011 projection by the International Energy Agency, solar power generators may produce most of the world’s electricity within 50 years.
Geothermal power (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat stored in the earth. This geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. It has been used for bathing since Paleolithic times and for space heating since ancient Roman times, but is now better known for generating electricity. Worldwide, about 10,715 megawatts (MW) of geothermal power is online in 24 countries. An additional 28 gigawatts of direct geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination and agricultural applications.
Geothermal power is cost effective, reliable, sustainable, and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels.
The Brazos Wind Farm in Texas. At the end of 2009 wind power accounted for about 2% of the electricity generated in the United States
... that The Clean Tech Revolution: The Next Big Growth and Investment Opportunity, the 2007 book by Ron Pernick and Clint Wilder, argues that commercializing clean technologies is a profitable enterprise that is moving steadily into mainstream business ? As the world economy faces challenges from energy price spikes, resource shortages, global environmental problems, and security threats, clean technologies are seen to be the next engine of economic growth.
Pernick and Wilder highlight eight major clean technology sectors: solar power, wind power, biofuels, green buildings, personal transportation, the smart grid, mobile applications (such as portable fuel cells), and water filtration. Very large corporations such as GE, Toyota and Sharp, and investment firms such as Goldman Sachs are making multi-billion dollar investments in clean technology.
- September 3, 2014: Australia's largest solar power station, the 20MW Royalla Solar Farm, is opened as part of a plan to reach 90% renewables by 2020 in the ACT (Canberra Times)
- August 14, 2014: In the first half of the year 31% of electricity in Germany was generated from renewables. (Business Week)
- August 7, 2014: Solar power capacity in China increased by 3.3GW in the first half of 2014, more than the entire solar capacity of Australia. (Bloomberg)
- July 30, 2014: France passes law that sets a renewable energy target of 32% by 2030. (Euractiv)
- July 15, 2014: The 138MW Jeffreys Bay wind farm in South Africa is inaugurated (REM).
- June 27, 2014: In the first quarter of 2014 a fifth of UK's electricity was from renewables (The Guardian).
- June 22, 2014: 72% of Australians support the 20% by 2020 renewable energy target despite government considering abolishing it. (The Guardian)
- June 20, 2014: Electricity production from solar energy in Germany reaches a record peak matching 50% of national demand on June 9. (Phys.org)
- June 19, 2014: Report shows that 22% of global electricity production in 2013 was from renewables. (Wall Street Journal)
- June 6, 2014: A 100MW solar plant in Chile, the largest in Latin America, is inaugurated. (abc27)
- "Renewable energy is proving to be commercially viable for a growing list of consumers and uses. Renewable energy technologies provide many benefits that go well beyond energy alone. More and more, renewable energies are contributing to the three pillars of sustainable development – the economy, the environment and social well-being – not only in IEA countries, but globally."
- "Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources."
– International Energy Agency, Renewable energy... into the mainstream, 2002.
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