Renewable energy is generally defined as energy that comes from resources which are naturally replenished on a human timescale such as sunlight, wind, rain, tides, waves and geothermal heat. Renewable energy replaces conventional fuels in four distinct areas: electricity generation, hot water/space heating, motor fuels, and rural (off-grid) energy services.
Based on REN21's 2014 report, renewables contributed 19 percent to our energy consumption and 22 percent to our electricity generation in 2012 and 2013, respectively. Both, modern renewables, such as hydro, wind, solar and biofuels, as well as traditional biomass, contributed in about equal parts to the global energy supply. Worldwide investments in renewable technologies amounted to more than US$ 214 billion in 2013, with countries like China and the United States heavily investing in wind, hydro, solar and biofuels.
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. 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.
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. 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.
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.
Template:/box-header WikiProjects connected with renewable energy:
- May 19, 2016: Final turbine of the 582MW German offshore Gode Wind Farm installed. (ReCharge)
- May 18, 2016: Renewable energy in Portugal supplies 100% of demand over four days in a row. (The Guardian)
- April 29, 2016: The Australian Capital Territory lifts its renewable energy target to 100% by 2020. (The Canberra Times)
- March 15, 2016: Bokpoort concentrated solar power inaugurated in South Africa. (ESI Africa)
- March 5, 2016: The 132MW Cadiz Solar Power Plant in the Philippines, the largest in Southeast Asia opens. (Deal Street Asia)
- February 5, 2016: Morocco completes the Noor 1 solar plant, the first stage of a 500MW project (The Japan Times)
- December 17, 2015: The 113MW Tafila Wind Farm in Jordan is inaugurated. (PR Newswire)
- December 2, 2015: The 300MW Cestas solar plant, the largest photovoltaic power station in Europe, is inaugurated near Bordeaux. (RenewEconomy)
- December 1, 2015: The 200MW Gulf of El-Zayt wind farm - the largest in Africa- is inaugurated in Egypt. (African Review)
- November 26, 2015: Mauritania's first wind farm inaugurated. (North Africa Post)
- "Ethanol creates U.S. jobs, cleans the air, strengthens national security – and best of all, it is here right now. Every day, ethanol producers are developing technological improvements to increase efficiency, reduce water use, and boost the amount of energy derived from corn kernels or from cellulosic biomass. Ethanol is not a 'someday' fuel. It is the renewable, clean-burning alternative we have to gasoline today."
- "Moreover, advancements in ethanol production are quickly opening the door for the commercialization of cellulosic ethanol and other advanced biofuels."
– Ethanol is Here Today Renewable Energy World, 19 August 2010.