The document defines renewable energy as energy from natural resources that can be reused sustainably without depleting the source. It lists several types of renewable energy resources: solar energy, wind power, hydropower, biomass, biofuels, and geothermal energy. For each type, it provides a brief definition and examples of technologies used to capture and convert the energy. It concludes by stating that renewable energy capacity, especially for solar and wind, grew significantly between 2004 and 2008.