Renewable energy flows involve natural phenomena such as sunlight, wind, tides, plant growth, and geothermal heat, as the International Energy Agency explains:
Renewable energy is derived from natural processes that are

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Prior to the development of coal in the mid 19th century, nearly all energy used was renewable. The oldest known use of renewable energy, in the form of traditional biomasst

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Hydropower
Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy. There are many forms of water energy:
• Historically,

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There are also other renewable energy technologies that are still under development, including cellulosic ethanol, hot-dry-rock geothermal power, and marine energy.

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Renewable energy production from some sources such as wind and solar is more variable and more geographically spread than technology based on fossil fuels and nuclear. While integrating it into the wider energy system is feasible, it does lead to some additional

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Renewable power has been more effective in creating jobs than coal or oil in the United States. In 2016, employment in the sector increased 6% in the United States while employment in the oil and gas sector decreased 18%. Worldwide, renewables employ about 8.1 million

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Policies to support renewable energy have been vital in their expansion. Where Europe dominated in establishing energy policy in early 2000s, most countries around the world now have some form of energy policy.
Policy trends

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