Renewable energy

Renewable energy is energy that can be continuously be used and refilled drawing usually from natural regenerative sources or natural environmental processes such as wind, solar, and bio. It is often contrasted with non-renewable sources such as coal and fossil fuels which take longer to generate. Renewable energy uses energy flows that are replenished at the same rate as they are used. Renewable energy can potentially help to mitigate and/or alleviate various environmental problems potentially.

About 13 percent of primary energy comes from renewables, with most of this coming from traditional biomass like wood-burning. Hydropower is the next largest source, providing 2-3%, and modern technologies like geothermal, wind, solar, and marine energy together produce less than 1% of total world energy demand but are expanding rapidly. The technical potential for their use is very large, exceeding all other readily available sources.

Examples
Current renewable energy technologies include:
 * Solar Energy
 * /Solar thermal/
 * /Photovoltaics/
 * /Bioenergy/
 * /Wind energy/
 * /Hydroelectric/
 * Non Solar Renewables
 * /Tidal energy/
 * /Geothermal energy/

Wind:
 * /Windstalk/

Lessons

 * 1) The energy challenge
 * 2) Key concepts of semiconductors
 * 3) Photovoltaics

Wikipedia

 * Hybrid renewable energy system
 * Biogasoline
 * List of renewable energy topics by country and territory
 * List of renewable energy organizations

External resources

 * OpenEI: Energy Data, Tools, Models, and other Resources
 * Open-source Renewable Energy Project
 * Overview of renewable energy wiki resources (Appropedia)
 * USA: National Center for Appropriate Technology (NCAT) | National Renewable Energy Laboratory | U.S. DOE Energy Efficiency and Renewable Energy (EERE)