In these times of worldwide skyrocketing energy costs, experts are turning to perhaps the only energy source that is still immune to price fluctuations: the Sun. Economic necessity appears to be largely responsible for the rapidly growing acceptance of solar heat as an alternative source. Electricity has been a clean and versatile form of energy that continues to grow in importance for lighting, heating and cooking and for powering our increasingly automated and computerised society. The demand for electricity is expected to grow more in future than the average trend in the past. A mix of energy sources is required as hedge against shortages in any one area and the electricity supply companies are taking a second look at renewable energy generating technologies, particularly those based on the Sun. Every 15 minutes, the Sun delivers to Earth radiant energy to meet all mankind's power needs for a full year. But harnessing this energy is complicated by two properties of sunlight its diffuseness and its variability with time of day, season and weather conditions.
These factors pose formidable technical challenges for the efficient conversion of solar radiation into bulk, utility grade electric power. Nevertheless, solar technologies are attractive to utilities because they are environment-friendly and offer a low regulatory risk, limited capital risk and less lead time.
What is the major difficulty in employing solar energy?