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Solar thermal energy refers to the idea of harnessing solar power for practical applications from solar heating to electrical power generation. Solar thermal collectors, such as solar hot water panels, are commonly used to generate solar hot water for domestic and light industrial applications. Solar thermal energy is used in architecture and building design to control heating and ventilation in both active solar and passive solar designs. This article is devoted primarily to solar thermal electric power plants, that is, solar power plants that generate electricity by converting solar energy to heat, to drive a thermal power plant. The article on photovoltaics reviews solar power generation by means of solar electric panels. Image File history File links Portal. ... Solar power describes a number of methods of harnessing energy from the light of the sun. ... Solar heating is a style of building construction which uses the energy of sunshine to heat a structure. ... A Solar thermal collector absorbs sunlight to provide heat. ... A solar heater A laundromat in California with solar hot water panels on the roof. ... Solar hot water describes heated water achieved through the usage of solar energy. ... The Parthenon on top of the Acropolis, Athens, Greece Architecture (from Latin, architectura and ultimately from Greek, αρχιτεκτων, a master builder, from αρχι- chief, leader and τεκτων, builder, carpenter) is the art and science of designing buildings and structures. ... Building design is the design of architectural exterior/interior spaces, engineered elements and shelter design. ... Active solar is a term which refers to the use of solar energy to actively convert the energy in sunlight into other forms. ... Passive solar is a broad category of techniques for regulating a buildings indoor air and domestic water temperatures, using climate, site features, architectural elements, and landscape materials. ... Oil power plant in Iraq A power station (also power plant) is a facility for the generation of electric power. ... Photovoltaics, or PV for short, is a solar power technology that uses solar photovoltaic arrays or solar cells to provide electricity for human activities. ...

Concentrated solar power (CSP) plants

In concentrating collectors, the area intercepting the solar radiation is greater, sometimes hundreds of times greater, than the absorber area. Where temperatures below about 95°C are sufficient, such as for space heating, flat-plate collectors of the nonconcentrating type are generally used. These hold temperatures "in stagnation" at between 150 and 220 degrees Celsius. It is not immediately apparent why one would concentrate solar energy using a parabolic reflector.

The total energy which can be intercepted is a function of area and a flat plate collector will intercept the same amount of energy as a parabolic reflector of the same area. However, the maximum theoretical efficiency of any heat engine is equal to the temperature difference between the hot and the cold end divided by the absolute temperature at the hot end. An energy concentrating device such as a parabolic mirror collects the same amount of energy as a flat plate collector of the same area but at a higher temperature. Thus, more useful energy can be extracted in the form of electricity or water pumping.

Solar Two, a concentrating solar power plant.

Image File history File links Download high resolution version (1468x1952, 2072 KB) Description: Solar Two in Daggett, CA. It was a 10-MW solar thermal electric power plant. ... Image File history File links Download high resolution version (1468x1952, 2072 KB) Description: Solar Two in Daggett, CA. It was a 10-MW solar thermal electric power plant. ...

Parabolic trough designs

Main article: Trough concentrator

Parabolic trough power plants are the most successful and cost-effective CSP system design at present. They use a curved trough which reflects the direct solar insolation onto a hollow tube running along above the trough. The whole trough tilts through the course of the day so that direct insolation remains focused on the hollow tube for as long as the sun shines. A fluid, normally thermal oil, passes through the tube and becomes hot. Full-scale parabolic trough systems consist of many such troughs laid out in parallel over a large area of land. A solar thermal system using this principle is in operation in California in the United States, called the SEGS system.^[1] At 350 MW, it is currently not only the largest operational solar thermal energy system, but the largest solar power system of any kind. SEGS uses oil to take the heat away: the oil then passes through a heat exchanger, creating steam which runs a steam turbine. The 64Mw Nevada Solar One plant also uses this design. Other parabolic trough systems, which create steam directly in the tubes, are under development; this concept is thought to lead to cheaper overall designs, but the concept is yet to be commercialized. A parabolic trough is a type of solar thermal collector. ... A parabolic trough is a type of solar thermal collector. ... This article is about the U.S. state. ... This article is in need of attention. ... Nevada Solar One will be the third largest solar power plant in the world, generating 64MW. Nevada Solar One is unrelated to Solar One, aside from having a similar name. ...

Power tower designs

Main article: Solar power tower

Power towers (also know as 'central tower' power plants or 'heliostat' power plants) use an array of flat, moveable 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 more 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 during the evening. Examples of heliostat based power plants are the 10 MWe Solar One (later called Solar Two), and the 15 MW Solar Tres plants. Neither of these are currently used for active energy generation. In South Africa, a solar power plant is planned with 4000 to 5000 heliostat mirrors, each having an area of 140 m².^[2] A solar power tower is a solar power station based on a tower. ... A solar power tower is a solar power station based on a tower. ... A Heliostat is a device that tracks the movement of the sun. ... Solar One is a pilot solar-thermal project in the Mojave Desert near Barstow, California. ... Solar One is a pilot solar-thermal project in the Mojave Desert near Barstow, California. ...

Dish designs

A dish system uses a large, reflective, parabolic dish (similar in shape to satellite television dish). It focuses all the sunlight that strikes the dish up onto to a single point above the dish, where a thermal collector is used to capture the heat and transform it into a useful form. Dish systems, like power towers, can achieve much higher temperatures due to the higher concentration of light which they receive. Typically the dish is coupled with a Stirling engine in a Dish-Stirling System, but also sometimes a steam engine is used. These create rotational kinetic energy that can be converted to electricity using an electric generator.^{[3] [4] [5]}. It has been suggested that Analyzing the parabola be merged into this article or section. ... A Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications. ... // The term steam engine may also refer to an entire railroad steam locomotive. ... Generator redirects here. ...

Fresnel designs

A linear Fresnel reflector power plant uses a series of carefully angled plane mirrors to focus light onto a linear absorber. Recent prototypes of these types of systems have been built in Australia (CLFR^[6]) and Belgium (SolarMundo). These systems claim to offer lower overall costs because they permit the heat-absorbing element to be shared between several mirrors. The mirrors can therefore be smaller and do not require complex pivoting couplings for the fluid flowing from the absorber. The design can also permit mirrors to be placed closer together, allowing for a more efficient use of land area.

Conversion rates from solar energy to electrical energy

Of these technologies the solar dish/stirling has the highest energy efficiency (the current record is a conversion efficiency of 40.7% of solar energy). A single solar dish-Stirling engine installed at Sandia National Laboratories’ National Solar Thermal Test Facility produces as much as 25 kW of electricity, while its footprint is a hundred times smaller than the spain solar updraft tower. ^[7] . Solar trough plants have been built with efficiencies of about 20%.
The Concentrated Solar Power (CSP) Plant using the parabolic trough principle called the SEGS system, in California in the United States,^[8] produces 330 MW, and it is currently the largest solar thermal energy system in operation. Furthermore, Southern California Edison announced an agreement to purchase solar powered Stirling engines from Stirling Energy Systems over a twenty year period and in quantities (20,000 units) sufficient to generate 500 megawatts of electricity. ^[9] Stirling Energy Systems announced another agreement with San Diego Gas & Electric to provide between 300 and 900 megawatts of electricity.^[10] In physics and engineering, including mechanical and electrical engineering, energy efficiency is a dimensionless number, with a value between 0 and 1 or with times 100 given in percent. ... A Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications. ... It has been suggested that Sandia Base be merged into this article or section. ... A parabolic trough is a type of solar thermal collector. ... This article is about the U.S. state. ... Southern California Edison, the largest subsidiary of Edison International (NYSE: EIX), is the primary electricity supply company for much of the lower half of the State of California, the region known as Southern California. ... A Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications. ... http://www. ... San Diego Gas & Electric (SDG&E) is the utility that provides natural gas and electricity to San Diego County and southern Orange County in southern California. ...

The gross conversion efficiencies (taking into account that the solar dishes or troughs occupy only a fraction of the total area of the power plant) are determined by net generating capacity over the solar energy that falls on the total area of the solar plant. The 500-megawatt (MW) SCE/SES plant would extract about 2.75% of the solar power (1 kW/m²; see Solar power for a discussion) that impinges on its 4,500-acres (18.2 km²).^[11] For the 50MW AndaSol Power Plant ^[12] that is being built in Spain (total area of 1,300×1,500 m = 1.95 km²) gross conversion efficiency comes out at 2.6% kW is a measure of power, kilowatt. ... Solar power describes a number of methods of harnessing energy from the light of the sun. ...

See also

• Solar power
• Solar heating
• Renewable energy

Solar power describes a number of methods of harnessing energy from the light of the sun. ... Solar heating is a style of building construction which uses the energy of sunshine to heat a structure. ... Renewable energy is defined as energy derived from resources that are regenerative or for all practical purposes can not be depleted. ...

Solar furnaces

• Solar furnaces
• Solar power tower
• Nevada Solar One
• Solar One
• Themis

A solar power tower is a solar power station based on a tower. ... Nevada Solar One will be the third largest solar power plant in the world, generating 64MW. Nevada Solar One is unrelated to Solar One, aside from having a similar name. ... Solar One is a pilot solar-thermal project in the Mojave Desert near Barstow, California. ...

Other applications of solar thermal energy in energy production

• Solar pond
• Solar updraft tower
• Energy Tower
• Energy Tower (Heat Pump Cooled)

A Solar pond is large-scale solar energy collector with integral heat storage for supplying thermal energy. ... now. ... An Energy tower is a new concept for producing electrical power for consumer consumption, the brainchild of Professor Dan Zaslavsky. ...

References

1. ^ SEGS system
2. ^ 100 MW Solar Thermal Electric Project in South Africa
3. ^ WorldChanging: Another World Is Here: Steampunk Solar Power
4. ^ RenewableEnergyAccess.com|World's Largest Solar Project Unveiled
5. ^ Stirling Energy Systems Inc. - Solar Overview
6. ^ CLFR
7. ^ Sandia National Laboratories (2004-11-09). Sandia, Stirling to build solar dish engine power plant. Press release.
8. ^ http://www.fplenergy.com/portfolio/contents/segs_viii.shtml
9. ^ http://pesn.com/2005/08/11/9600147_Edison_Stirling_largest_solar/
10. ^ http://www.stirlingenergy.com/breaking_news.htm
11. ^ Major New Solar Energy Project Announced By Southern California Edison and Stirling Energy Systems, Inc., press release
12. ^ 2x50MW AndaSol Power Plant Projects in Spain

It has been suggested that Sandia Base be merged into this article or section. ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... November 9 is the 313th day of the year (314th in leap years) in the Gregorian Calendar, with 52 days remaining. ... A news release, press release or press statement is a written or recorded communication directed at members of the news media for the purpose of announcing something claimed as having news value. ...

External links

• Concentrating Solar Thermal Systems
• Solar Energy
• Links.
• Solar thermal technology for Central Power Generation and Power Stations.

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