Solar thermal energy is heat energy obtained by exposing a collecting device to the rays of the sun. A solar thermal system makes use of the warmth absorbed by the collector to heat water or another working fluid, or to make steam. Hot water is used in homes or commercial buildings and for industrial processes. Steam is used for process heat or for operating a turbine generator to produce electricity or industrial power. Advantages Solar thermal energy makes use of a renewable natural resource which is readily available in most parts of the world.
Solar energy used by itself creates no carbon dioxide or other toxic emissions.
The heated fluid can be stored in insulated tanks allowing energy to be used during brief cloudy or overcast periods. New equipment and technological advances have reduced the cost of solar thermal power to a level that can be competitive with fossil-fuel generated electricity in some areas. Use of solar thermal energy to heat water or generate electricity will help reduce the state's almost complete dependence on imported fossil fuels. The State of Hawaii offers a 35 percent tax credit for the cost of buying and installing a solar thermal device which supplies hot water for single family homes or multi-unit residential buildings. Solar water heaters are an established technology, readily available on the commercial market, and simple enough to build, install and maintain by yourself.