Solar energy

Abstract

Every hour, enough solar radiation reaches the earth to meet the entire annual energy demand of the world's population. The solar radiation at a given location varies according to the time of day and year, and prevailing weather conditions. Peak values for solar radiation on clear sunny days are around 1000 W/m2. In temperate climatic regions, the annual total for solar energy is 1,000-1,200 kWh/m2; it can reach 2,500 kWh/m2 in arid desert zones. © 2009 Springer Berlin Heidelberg.