Solar Power Generation

Jul„P ugust 19E8 SOLAR POWER GENERATION The sun converts 600 million tons of hydrogen into helium through nuclear fusion every second, and in the process re- leases enough energy to meet our earthly needs for a million years. Of course, only a tiny part of the solar energy falls onto earth, which is readily seen when it is realized that the sun radiates equally in all direc- tions. Since the average distance from the sun to the earth is near enough 150 million kilometres, the energy (in the form of electromagnetic radi- ation) takes about 8 minutes to reach the earth. In that time, the total energy radiated by the sun has spread over the inside of a sphere of surface area 3 x10"7km 2. The total surface area of the earth that can be lit by the sun at any one time amounts to 113 x 106km2. This means that only about 4 ten- thousandmillionth parts of the totally radiated energy falls onto earth. The rest is lost in the universe. The solar energy that reaches the earth can be convert...