Pub. date: 2011 | Online Pub. Date: May 04, 2010 | DOI: 10.4135/9781412973816 | Print ISBN: 9781412996822 | Online ISBN: 9781412973816 | Publisher:SAGE Publications, Inc.About this encyclopedia
Renewable energy is the energy produced by using natural resources that will regenerate in time. Primary sources of renewable energy are water, geothermal heat, wind, and sunlight. The energy produced by using different organic materials, such as wood, agricultural rejects, forestry residues, and urban solid waste (called biomass) is also regarded as “renewable.” According to authoritative international agencies like the United Nations Environment Programme and the Intergovernmental Panel on Climate Change, renewable energies represent the mo st realistic alternative to fossil fuels. At present, renewable sources are employed chiefly in the production of electricity, but also to produce biofuels and to provide heat for industrial and private users. Over the last 10 years, the development of renewable energies has been stimulated by concern over global warming. At this time, it is believed that renewable energy sources will play a key role in limiting greenhouse gases emissions. Hydroelectric energy has represented, ...