Renewable energy effectively uses natural resources such as sunlight, wind, rain, tides and geothermal heat, which are as expected replenished. Renewable energy technologies series from solar power, wind power, hydroelectricity/micro hydro, biomass and biofuels for transportation.

Let me start first by telling you that America has got to change its habits. We've got to get off oil. And the reason why is, first, oil is -- dependency on oil presents a real challenge to our economy. As economies grow -- and we want all our economies to grow; we want people to be prosperous, we want people who are living in poverty to be able to grow out of poverty. We want there to be general prosperity, but as economies grow, until we change our habits, there is going to be more dependency on oil.

The majority of renewable energy technologies are directly or indirectly powered by the sun. The Earth-Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar radiation, the resulting level of energy within the Earth-Atmosphere system can roughly be described as the Earth's "climate." The hydrosphere (water) absorbs a major fraction of the incoming radiation. Most radiation is absorbed at low latitudes around the equator, but this energy is dissipated around the globe in the form of winds and ocean currents. Wave motion may play a role in the process of transferring mechanical energy between the atmosphere and the ocean through wind stress.[19] Solar energy is also responsible for the distribution of precipitation which is tapped by hydroelectric projects, and for the growth of plants used to create biofuels.