We usually think of solar energy simply as sunlight, but the term includes many other renewable resources available around us.
When the sun heats the earth, it triggers atmospheric changes. These changes take the form of tides, rainfall or wind. Differences in ocean temperatures can also occur. The sun helps trees grow and plants thrive so they might eventually serve as secondary fuel sources such as firewood and alcohol.
Obtaining energy is possible from these secondary sources of solar energy as well as from the sun itself. The water resources for hydroelectric power, for example, are completely renewable, with solar energy an important part of the cycle. Heat from the sun evaporates water from the surfaces of oceans and lakes. Clouds store this water, and it returns to the earth as rain and snow.
Electric power producers work increasingly with the sun. We are evaluating and improving methods that range from solar water heaters to photovoltaic (C4a4) cells and from wind power to biomass conversion.