When technology is used to derive usable energy from the light of the sun one calls it solar power and the use of solar energy has been known and used by traditional technologies for centuries and is most used where other power supplies are not present like in space or in remote locations on the earth. Solar power has been used in heating, generation of electricity as well as in desalination of seawater and its application is becoming more widespread as the costs as well as supply of other power sources like fossil fuels make it an effective source for energy generation. There are a number of different uses for solar power and solar heating systems are one such use.
Solar Heating Systems
Solar hot water systems make use of sunlight to heat up water and these systems are found in domestic appliances that heat domestic water or for space heating and are basically composed of solar thermal collectors as well as a storage tank. There are three types of solar water heaters that make use of solar power and these are active systems that use pumps in order to circulate water or to heat transfer fluids and the passive systems that circulate water or heat transfer fluid through natural circulation and are known as thermosiphon systems and the third type is the batch system that use a tank that is heated by sunlight, directly.
Another use of solar power is in solar cooking where a solar box cooker traps the energy from the sun into an insulated box and these are useful in cooking, pasteurization as well as fruit canning and are in use in many developing countries to reduce the demand for firewood as well as to keep the environment clean. Solar lighting is another use of solar power where use of natural light to supply illumination is used to save energy and it offers physiological as well as psychological benefits.
There are also large scale uses for solar power as are in the case of solar thermal electric power plants where solar thermal energy may be used in heating a heat exchanger to high temperatures and the heat is then used in the production of electric power or for other industrial uses. Also, solar power technologies may be classified as direct or indirect and normally, direct solar power involves a single transformation of sunlight in order to get energy that can be used and in such cases sunlight may be used to hit photovoltaic cells to create electricity or it may warm a thermal mass or it may strike a solar sail such as those found on spacecrafts and there are also many other means of deriving direct solar power. Indirect solar power involves multiple conversion of sunlight to obtain useable energy forms.