- Heliostat
A Heliostat (from "
helios ", the Greek word for "sun", and "stat", as in stationary) is a device that tracks the movement of thesun . It is typically used to orient amirror , throughout the day, to redirect sunlight along a fixed axis towards a stationary target or receiver.Heliostats are used in
solar telescope s, andsolar power generation. Heliostats have been used insurveying in the form of a heliotrope to constantly reflect sunlight in a single fixed direction, allowing the accurate observation of a known point from a distance.The simplest heliostat devices use an
equatorial mount and a clockwork mechanism to turn the mirror in synchronisation with the rotation of the Earth. More advanced heliostats track the sun directly by sensing its position throughout the day. Others are controlled by computers.A siderostat is a similar device which is designed to track a fainter
star , rather than the Sun.Large scale projects
Many heliostats can be combined together to concentrate the sun's energy. Energy can be collected for electrical generation with
photovoltaic cells or can be used to heat a medium such as water or molten salt, as in theThe Solar Project . The high temperatures can also be used as an incinerator for waste disposal.See also
*
Renewable energy
*Solar cell
*Solar power
*Solar power tower
*Solar thermal energy
*Solar tracker External links
* [http://www.practicalsolar.com/Image%20Gallery.htm Photos of heliostats in action]
* [http://www.promes.cnrs.fr/TOUT-PUBLIC/Les-fours/eng-lesfours1.htm Field of 63 heliostats at the Odeillo Solar Furnace]
* [http://www.promes.cnrs.fr/MOYENS/Concentrateurs/eng-concentrateur1.htm Solar Furnaces at Odeillo]
* [http://www.redrok.com/main.htm redrok.com]
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