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Acciona Energy, an alternative energy company based out of Spain, can boast about its reputation for building clean technologies, and lots of them. They are the world leader in wind power, totalling 5,300MW in 192 separate wind parks, and built the first modern concentrating solar plant in the US, the Nevada Solar One (pictured above), to date the 3rd largest in the world, and they keep expanding. They announced today that they are planning on building 2 solar thermal plants in Cordoba, Spain, each with a capacity of 50MW, entering into service in 2010, and costing 500 million euros (roughly $850 million). The two facilities will produce an amazing 224 million KWh per year, the equivalent of 75,000 homes.
The plants will cover the area of about 260 hectares, or 364 soccer fields, comprising 1,520 solar collectors and a truly mind boggling 364,800 mirrors which will focus the sun’s rays into the collectors. This will complement the 2,000MW of solar thermal currently under development in the US, mostly located in the Mojave desert. While some solar thermal towers use liquid salt as a heat exchange medium, Acciona’s design is based on an oil system, which works like this:
“A fluid (oil) runs through these tubes that reaches a very high temperature (400º C). This fluid is sent from the solar field to the power unit where the heat is transferred to a heat exchanger, through which water runs that turns into steam. The steam is taken to a turbine connected to a generator that produces electricity. Following its transformation to high voltage it will be evacuated to the grid through a substation at Villanueva del Rey (in the municipality of Écija).”
Thermal solar power plants have the advantage of producing their peak power during the hottest part of the day, when demand for electricity is generally the highest. The disadvantage, however, is that it cannot actively produce energy during the night and must rely on passive heat remaining in the system, or stored energy which can be released (underground compressed air storage, stored energy flywheels, etc.)
via Ecolectic.org
