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Portal:Renewable energy


Wind, solar, and hydroelectricity 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.

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 don't 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. Their share of total energy consumption is increasing. Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas.

Selected article

Wind, wave and tide make up more than 80% of Scotland's renewable energy potential.

The natural resource base for renewable energy in Scotland is extraordinary by European, and even global standards. In addition to an existing installed capacity of 1.3 Gigawatts (GW) of hydro-electric schemes, Scotland has an estimated potential of 36.5 GW of wind and 7.5 GW of tidal power, 25% of the estimated total capacity for the European Union and up to 14 GW of wave power potential, 10% of EU capacity. The renewable electricity generating capacity may be 60 GW or more, considerably greater than the existing capacity from all Scottish fuel sources of 10.3 GW.

Much of this potential remains untapped, but continuing improvements in engineering are enabling more of the renewable resources to be utilised. Fears regarding "peak oil" and climate change have driven the subject high up the political agenda and are also encouraging the use of various biofuels. Although there is significant support from the public, private and community-led sectors, concerns about the effect of the technologies on the natural environment have been expressed.


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Aerial view of Europe's most powerful solar power towers, near Seville, Spain
PS10 and PS20, Europe's most powerful solar power towers, near Seville, Spain

Selected biography

Hans-Josef Fell1.JPG

Hans-Josef Fell (born 7 January 1952 in Hammelburg) is a member of the Green Party in the German Parliament. Fell framed the German Renewable Energy legislation, together with Hermann Scheer. He currently serves as spokesman on energy for the Alliance 90/The Greens parliamentary group.

Fell has travelled to many countries to discuss clean energy. Following his visit to Turkey, plans for a nuclear power plant at Akkuyu were stopped, and Prime Minister Bülent Ecevit declared that his government would foster renewable technologies. In Taiwan, following Fell's television appearances and talks with individual policy makers, the government announced the withdrawal of its plans to build the country's fourth nuclear power plant, and its intent to phase out nuclear power by 2020. The French government has also shown great interest in drafting a renewable energy law similar to the one in Germany.


Did you know?

... 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.




  • "People do not want electricity or oil ... but rather comfortable rooms, light, vehicular motion, food, tables, and other real things."
  • "There exists today a body of energy technologies that have certain specific features in common and that offer great technical, economic, and political attractions ... 'soft' energy technologies [which are] flexible, resilient, sustainable, and benign. They rely on renewable energy flows that are always there whether we use them of not, such as sun and wind and vegetation."
  • "Soft technologies' matching of energy quality to end-use needs virtually eliminates the costs and losses of secondary energy conversion, [and] the appropriate scale of soft technologies can virtually eliminate the costs and losses of energy distribution."

Amory Lovins, Soft Energy Paths, 1977, pp. 38–40.

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