3. Solar Radiation Resource

The sun is the main source of renewable energy. It emits radiation at an equivalent black body temperature of about 6,000 K with a constant intensity outside the earth’s atmosphere. Only direct (beam) radiation is available outside the earth’s atmosphere. As solar radiation propagates through the atmospheric matter, it is attenuated, producing direct and diffuse components which reach the earth surface. Only the direct component can be focused and is, therefore, useful in the development of concentrating solar power (CSP) technologies. Absorption of solar radiation by a receiving surface is maximum when the angle of incidence is zero, and the surface is said to receive direct normal irradiation. The recommended minimum annual sum of direct normal irradiation for CSP technology to be economically viable is 2,000 kWh/m², and many locations within the sunbelt meet this threshold. It has been found that the worldwide technical potential of CSP is estimated at 3,000,000 TWh/year which significantly exceeds the world electricity consumption level of about 29,000 TWh/year in 2015. This level of solar energy resource availability is attractive for the advancement of the solar gas turbine technology.