Solar Energy Generating Systems

Solar Energy Generating Systems (SEGS) is the largest solar energy generating facility in the world. It consists of nine solar power plants in California's Mojave Desert, where insolation is among the best available in the United States. FPL Energy operates and partially owns the plants. SEGS III-VII (150 MW) are located at Kramer Junction, SEGS VIII-IX (160 MW) at Harper Lake, and SEGS I-II (44 MW) at Daggett respectively. [http://thefraserdomain.typepad.com/energy/2005/09/about_parabolic.html The Energy Blog: About Parabolic Trough Solar ] ]

Plants' scale

The plants have a 354 MW installed capacity, making it the largest installation of solar plants of any kind in the world. [http://thefraserdomain.typepad.com/energy/2005/09/about_parabolic.html The Energy Blog: About Parabolic Trough Solar ] ] By comparison, the largest photovoltaic plant, which is in Spain, produces 23 MW, although a 62 MW PV installation (Moura photovoltaic power station) is under construction in Portugal [http://www.ipsnews.net/news.asp?idnews=38245 "PORTUGAL: Making Up for Lost Time in Renewable Energy"] , "Inter Press Service", 2006-10-02. Retrieved on 2008-02-26.] and a 154 MW PV Solar power station in Victoria, Australia, is planned. [ [http://technology.timesonline.co.uk/tol/news/tech_and_web/article613720.ece Australia advances with solar power] "The Times", 26 October 2006.] The average gross solar output for all nine plants at SEGS is around 75 MWe. In addition, the turbines can be utilized at night by burning natural gas.

Land footprint

The facilities have a total of 936,384 mirrors and cover more than convert|1600|acre|km2|sigfig=2. Lined up, the parabolic mirrors would extend over convert|229|mi|km.

Fossil fuel equivalent

FPL claims that their solar plants displace 3,800 tons of pollution per year, they power 232,500 homes, and their energy displaces 815,000 barrels of oil annually.cite web
url=http://www.fplenergy.com/portfolio/pdf/solar_factsheet.pdf
title=Solar Electric Generating System
accessdate=2008-06-04] [cite web
url=http://www.fplenergy.com/portfolio/solar/
title=FPL Energy - Solar
accessdate=2008-06-04]

Principle of operation

The installation uses parabolic trough solar thermal technology along with natural gas to generate electricity. 90% of the electricity is produced by the sunlight. Natural gas is only used when the solar power is insufficient to meet the demand from Southern California Edison, the distributer of power in southern California.

Mirrors

The parabolic mirrors are shaped like a half-pipe. The sun shines onto the panels made of glass, which are 94% reflective, unlike a typical mirror, which is only 70% reflective. The mirrors automatically track the sun throughout the day. The greatest source of mirror breakage is wind, with 3000 typically replaced each year. Operators can turn the mirrors to protect them during intense wind storms. An automated washing mechanism is used to periodically clean the parabolic reflective panels.

Heat transfer

The sun bounces off the mirrors and is directed to a central tube filled with synthetic oil, which heats to over convert|400|C|F|sigfig=2. The reflected light focused at the central tube is 71 to 80 times more intense than the ordinary sunlight. The synthetic oil transfers its heat to water, which boils and drives the Rankine cycle steam turbine,cite web
url=http://www.solel.com/products/pgeneration/ls2/
title=Solar thermal power generation
publisher = Solel Solar Systems Ltd
accessdate=2008-09-12] thereby generating electricity. Synthetic oil is used to carry the heat (instead of water) to keep the pressure within manageable parameters.

Individual locations

The SEGS power plants were built by Luz Industries, and commissioned between 1984 and 1991. Kramer Junction employs about 95 people and 45 people work at Harper Lake.

Harper Lake

SEGS VIII and SEGS IX, located at Coord|35.0316|-117.348|format=dms, are the largest solar power plants individually and collectively in the world. [ [http://www.osti.gov/accomplishments/pdf/DE00014520/DE00014520.pdf Solar Trough Power Plants] ] They were the last, the largest, and the most advanced of the nine plants at SEGS, designed to take advantage of the economies of scale. SEGS VIII and IX have operated continuously and have been commercially successful since the very beginning.

Kramer Junction

This location (Coord|35.0142|-117.559|format=dms) receives an average of 340 days of sunshine per year, which makes it an ideal place for solar power generation. The average direct normal radiation (DNR) is 7.44 kWh/m²/day (310 W/m²),Citation
first = Scott
last = Frier
author-link =
contribution = An overview of the Kramer Junction SEGS recent performance
contribution-url = http://www.nrel.gov/csp/troughnet/pdfs/1999_kjc.pdf
title = Parabolic Trough Workshop
year = 1999
pages =
place = Ontario, California
publisher = KJC Operating Company
format = PDF
url =
doi = ] one of the best in the nation.

Daggett

SEGS I and II are located at Coord|34.8631|-116.827|format=dms.

Gallery

See also

* List of solar thermal power stations
* Parabolic trough
* Solar power
* Solar power plants in the Mojave Desert
* Solar thermal energy

References

External links

* [http://www.fplenergy.com/portfolio/contents/segs_viii.shtml Official web site]
* [http://www.solel.com/faq/ Ten facts about solar thermal power]