Solar Thermal Technology

Solar thermal is a relatively new technology which has already shown enormous promise. It is a larger energy source than is commonly perceived and currently provides about half the energy generated from wind power and more than geothermal, solar photovolatics and ocean energy combined. At the end of 2007 there was 93,000 MW of wind power, 148,000 MW of solar thermal collectors for water heating and building heating or cooling installed, but only 414 MW of high temperature solar thermal collector generating capacity and about 8,000 MW of solar PV capacity.

With few environmental impacts and a big resource, solar thermal energy offers an opportunity to the sunniest countries of the world, comparable to that currently benefiting European nations with the windiest shorelines.

Solar thermal power uses direct sunlight, so it must be sited in regions with high direct solar radiation. Among the most promising areas of the world are the South-Western United States, Central and South America, Africa, the Middle East, the Mediterranean countries of Europe, Iran, Pakistan and the desert regions of India, the former Soviet Union, China and Australia.

In contrast, solar photovoltaic cells use both direct and indirect, diffuse solar radiation and they are suitable in areas with indirect, diffuse solar conditions, such as many north European regions and is more effective in cold conditions.

In many regions of the world, one square kilometre of land is enough to generate as much as 100-200 GWh of electricity per year using solar thermal technology. This is equivalent to the annual production of a 50 MW conventional coal or gas-fired power plant.