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 The Solar Car Book A complete kit for making a cool solar racecar. Everything is included: wheels, axles, motors, wires and a genuine one-volt solar cell. |
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Build Your Own Solar Furnace
See also:
Solar Chimney Solar Air Conditioning Solar Pond Salt Evaporation Pond Solar Furnace Solar Cooker Solar Still Solar Water Disinfection Solar Desalination
A solar furnace is a structure used to harness the rays of the sun in order to produce high temperatures. This is achieved by using a curved mirror (or an array of mirrors) acting as a parabolic reflector to concentrate light (Insolation) on to a focal point. The temperature at the focal point may reach up to 3,000 degrees Celsius, and this heat can be used to generate electricity, melt steel or make hydrogen fuel. The solar power tower is a type of solar furnace using a tower to receive the focused sunlight (see below). The solar furnace at Odeillo in the Pyrenees of France was opened in 1970 and is the largest in the world. It employs an array of plane mirrors to gather the rays of light from the sun and reflects them on to a larger curved mirror. The rays are focused on to an area the size of a cooking pot and can reach up to 3,000 degrees Celsius. The first modern solar furnace is believed to have been built in France in 1949 by Professor Félix Trombe. It is still in place at Mont Louis, near to Odeillo. The Pyrenees were chosen as the site for these furnaces due to the weather being sunny for up to 300 days a year. [1] It has been suggested that solar furnaces could be used in space to provide energy for manufacturing purposes, although their reliance on sunny weather means that they are unlikely to be used as a major source of renewable energy on Earth. The ancient Greek / Latin term "heliocaminus" literally means "solar furnace" - A glass-enclosed sunroom intentionally designed to become hotter than the outside air temperature.[2] Today, the term "solar furnace" has evolved to refer to solar concentrator heating systems using parabolic mirrors or heliostats. 1,000 degrees Fahrenheit (538 degrees Celsius) is now being commonly achieved. The theoretical maximum is the 5778 degree Kelvin surface temperature of the sun [3], although the practical limit (due to atmospheric absorption and rapid heat transfer at high temperature differentials) is much lower. During the Second Punic War (218 - 202 BCE), the Greek scientist Archimedes is said to have repelled the attacking Roman ships by setting them on fire with a "burning glass" that may have been array of mirrors. An experiment to test this theory was carried out by a group at the Massachusetts Institute of Technology in 2005. It concluded that although the theory was sound for stationary objects, the mirrors would have been unlikely to concentrate sufficient solar energy to set a ship on fire under battle conditions.[4] The solar furnace principle is being used to make inexpensive solar cookers, solar-powered barbecues, and for solar water pasteurization. [5][6] [7] See alsoReferences
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The solar power tower (also known as 'Central Tower' power plants or 'Heliostat' power plants or power towers) is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors (called heliostats) to focus the sun's rays upon a collector tower (the target). The high energy at this point of concentrated sunlight is transferred to a substance that can store the heat for later use. The most recent heat transfer material that has been successfully demonstrated is liquid sodium. Sodium is a metal with a high heat capacity, allowing that energy to be stored and drawn off throughout the evening. That energy can, in turn, be used to boil water for use in steam turbines. Water had originally been used as a heat transfer medium in earlier power tower versions (where the resultant steam was used to power a turbine). This system did not allow for power generation when the sun is not shining. Examples of Heliostat Power PlantsThe 10 MWe Solar One and Solar Two heliostat demonstration projects in the Mojave Desert have now been decommissioned. The 15 MW Solar Tres Power Tower in Spain builds on these projects. In Spain the 11 MW PS10 solar power tower was recently completed. In South Africa, a solar power plant is planned with 4000 to 5000 heliostat mirrors, each having an area of 140 m². A site near Uppington has been selected.[1][2] Cost
The US National Renewable Energy Laboratory NREL has estimated that by 2020 electricity could be produced from power towers for 5.47 ₡/kWh.[3] There is some hope that the development of cheap, low maintenance, mass produceable heliostat components could bring this cost down in the near future. [4] See alsoReferences
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This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia Encyclopedia article "Solar Furnace" |
