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Solar PowerSolar energy is energy derived from the light and heat reaching the earth from the sun. As a result, there are no greenhouse gases produced directly by the use of this energy source. The use of solar power fits basically into two categories; the first category would be called solar thermal technologies and uses the sun to generate heat; the second category converts solar power directly into electricity and is called photovoltaics. Solar Thermal Technologies Passive solar heating. Passive solar heating means that the heat from the sun is used without employing anything mechanical. This would include building's site orientation with south facing windows and interior materials that absorb heat. This method also requires applying shade to block the heat intensive rays from the sun during the summer. Passive solar heating is most conducive to residences, but significant strides have been made, especially in Europe, using passive solar heating in office buildings. Active solar heating. Solar thermal collectors are the key components of this type of solar heating. The most predominant device in this type of system is the flat-plate collector. It is commonly used for residential water-heating and space-heating installations. A flat-plate collector is an insulated metal box with a glass or plastic cover (called the glazing) and a dark-coloured absorber plate. This type of collector can heat either liquid or air - often the liquid is potable household water. Solar Concentrator Power Systems. These are devices that concentrate solar radiation onto a receiver, where the radiation is converted into thermal energy. This energy is then transported and finally converted into electricity. The concentrated solar radiation is targeted at a receiving device that is usually filled with liquid. The extremely hot liquid is then pumped through heat exchangers that create steam to drive either a turbine or a steam engine. The turbine or steam engine can then create electricity. Photovoltaics (PV) The second main method for capturing the sun's energy is through the use of photovoltaics. Photovoltaics (PV) utilize the sun's photons or light to create electricity. PV technologies rely on the photoelectric effect first described by French physicist Edmund Becquerel in 1839. The photoelectric effect occurs when a beam of UV light, composed of photons (quantified packets of energy), strikes one part of a pair of negatively charged metal plates. This causes electrons to be "liberated" from the negatively charged plate. These free electrons are then attracted to the other plate by electrostatic forces. This flowing of electrons is an electrical current. This electron flow can be gathered in the form of direct current (DC). This DC can then be inverted into alternating current (AC), which is the electrical power that is most commonly used in buildings in North America. Resources: Saskatchewan Find out how a growing number of rural people throughout Saskatchewan are proving that solar and wind power are now both viable and cost effective here. SaskEnergy has compiled a list of Solar Providers in Saskatchewan Canada Canadian Renewable Energy Program - comprehensive coverage of all renewable resources, including solar. Canadian Solar Industries Association - supplies innovative solar solutions for the domestic market. Solar Energy Ltd. - Canada's largest supplier of photovoltaic systems. Good technical information site. International Centre for the Analysis and Dissemination of Demonstrated Energy Technologies - international information on renewable technologies. Site hosted by the International Energy Agency (IEA) and the Organization for Economic Cooperative Development (OECD). Sunstone Organization - a website that shows how to build solar cookers and water heaters. US Dept. of Energy - the DOE's Solar Thermal Technologies website. US National Renewable Energy Laboratory - application of both solar thermal and photovoltaic technologies in buildings. NewsLetters EIN Publishing - "EIN publishes dozens of targeted summaries each day, designed for subscribers who require timely information on focused and specific topics" (solar included as a specific topic). Newsletter from Germany, who are leaders in Europe in wind energy. Solar Access.com - newsletter with solar news and applications for solar energy around the world. |
