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Portal:Renewable energy

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Wind, solar, and hydroelectricity[how?] are three emerging renewable sources of energy.

Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.

Based on REN21's 2017 report, renewables contributed 19.3% to humans' global energy consumption and 24.5% to their generation of electricity in 2015 and 2016, respectively. This energy consumption is divided as 8.9% coming from traditional biomass, 4.2% as heat energy (modern biomass, geothermal and solar heat), 3.9% hydro electricity and 2.2% is electricity from wind, solar, geothermal, and biomass. Worldwide investments in renewable technologies amounted to more than US$286 billion in 2015, with countries such as China and the United States heavily investing in wind, hydro, solar and biofuels. Globally, there are an estimated 7.7 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer. As of 2015 worldwide, more than half of all new electricity capacity installed was renewable.

Renewable energy resources exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries. Rapid deployment of renewable energy and energy efficiency is resulting in significant energy security, climate change mitigation, and economic benefits. The results of a recent review of the literature concluded that as greenhouse gas (GHG) emitters begin to be held liable for damages resulting from GHG emissions resulting in climate change, a high value for liability mitigation would provide powerful incentives for deployment of renewable energy technologies. In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power.

At the national level, at least 30 nations around the world already have renewable energy contributing more than 20 percent of energy supply. National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond. Some places and at least two countries, Iceland and Norway generate all their electricity using renewable energy already, and many other countries have the set a goal to reach 100% renewable energy in the future. For example, in Denmark the government decided to switch the total energy supply (electricity, mobility and heating/cooling) to 100% renewable energy by 2050. At least 47 nations around the world already have over 50 percent of electricity from renewable resources, with Iceland generating all its electrical power from renewable energy though this does not include non-electrical energy (e.g. transport and heating).

While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Former United Nations Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity. As most of renewables provide electricity, renewable energy deployment is often applied in conjunction with further electrification, which has several benefits: Electricity can be converted to heat (where necessary generating higher temperatures than fossil fuels), can be converted into mechanical energy with high efficiency and is clean at the point of consumption. In addition to that electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements, because most renewables do not have a steam cycle with high losses (fossil power plants usually have losses of 40 to 65%).

Renewable energy systems are rapidly becoming more efficient and cheaper and their share of total energy consumption is increasing. Global installed electricity generating capacity in 2017 was 2.2 TW. Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas.

Selected article

Krafla Geothermal Station

Domestically produced renewable energy in Iceland represents 85% of total primary energy supply. In 2011, geothermal energy provided about 65% of primary energy, the share of hydro power was 20%, and fossil fuels (mainly oil) 15%. The main use of geothermal energy is for space heating with the heat being distributed to buildings through extensive district-heating systems.

Renewable energy provides 100% of electricity production, with about 75% coming from hydropower and 25 percent from geothermal power. Most of the hydropower plants are owned by Landsvirkjun (the National Power Company) which is the main supplier of electricity in Iceland.


Selected image

Hybrid Power System.gif
Hybrid power systems are often used in rural and remote areas

Selected biography

Jeremy Leggett 18Aug2007.JPG

Jeremy Leggett, a geologist by training, began his career as a consultant for the oil industry, while teaching at the Royal School of Mines. He later became an environmental campaigner for Greenpeace, before evolving into a social entrepreneur and author.

Jeremy Leggett is currently executive chairman of Solarcentury the UK’s largest independent solar electric company. He also serves as a founding director of the world's first private equity fund for renewable energy. From 2002 to 2006, Leggett was a member of the UK Government Renewables advisory board. He was the recipient of the President's Award of the Geological Society, and in 1987 the Geological Society's Lyell Fund.

In his 2009 book, The Solar Century, Leggett is critical of nuclear power, saying that investing in nuclear power would mean less money for other initiatives involving energy conservation, energy efficiency, and renewable energy. Leggett also states that carbon capture and storage has a "substantial timing problem" as it will take fifteen to twenty years to introduce the technology.


Did you know?

... that REN21, the Renewable Energy Policy Network for the 21st Century, is a policy network that provides a forum for international leadership in renewable energy policy, in order to share knowledge and facilitate the rapid growth of renewable energy technologies in developing countries and industrialised economies ?

The network launched in June 2005, operates from offices in Paris, France, and is provided by the United Nations Environment Programme and the Deutsche Gesellschaft für International Zusammenarbeit in collaboration with the International Energy Agency. Since 2005 REN21 has produced an annual Renewables Global Status Report, with Eric Martinot and Janet Sawin as lead authors.




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