ABSTRACT
All energy on Earth has its origin in solar radiation. This statement is certainly true for all biomass, hydropower, and wind power. A reliable source of solar energy is the hydroelectric plant. Water evaporation with subsequent rainfall in connection with variation in height of Earth terrain is the necessary conditions. The wave motion of the oceans is caused by wind and thus is a consequence of solar radiation. The possible technical use of this energy is restricted to specific areas of the globe where it may be extracted with a degree of efficiency sufficient to warrant complex installations. The origin of the hot springs is seen in the fact of long-term chemical and radioactive reactions in the interior of the lithosphere and therefore, a gradual disintegration of the radioactive elements in the crust. The renewable energy sources are almost all sun related. Most important is the sun's direct radiation.
