Renewable energy (RE) is most often defined to be energy derived from inexhaustible sources‹the sun, the wind, and the Earth. In addition, renewable energy options often include the use of wastes to produce high valued and useful energy.

The use of renewable energy has the advantage of producing little or no carbon emissions. Wind power, photovoltaics, biomass derived from sources that are continuously replenished, and hydroelectricity have no net carbon emissions. Although energy derived from wastes can emit carbon, such emissions are usually no more than for natural gas-based systems. As a result, using renewable energy in lieu of fossil-based systems would significantly lower carbon (and GHG) emissions.

Approximately 30 quadrillion Btus of renewable energy are currently consumed throughout the world. This represents approximately 8% of world energy consumption. Although the large majority of renewable energy consumption is from large hydroelectric sources (and in some countries, biomass), use of biomass, wind and photovoltaics is growing rapidly. For example, it is estimated that, for each of the last few years, more than 1,200 MW of new wind generating capacity have been installed throughout the world.

Significant market opportunities for renewable energy exist. This section provides information on the factors that will influence the viability of each type of renewable enrgy. It also provides some information on sources for financing renewable energy projects.