The clean energy project is poised for the big leap with the commissioning of a new solar thermal plant in Spain. The technology behind the plant can tackle effectively storage-related problems and hence is seen as a key weapon in the combat against global warming.
Abengoa Solar operates the new plant, which has a power capacity of 20 megawatts, enough to generate power for about 10,000 homes.
Located near the ancient city of Seville, the PS-20 is now the second such tower collector in commercial use, but larger.
A solar thermal collector
is a solar collector specifically intended to collect heat: that is, to absorb sunlight to provide heat. Although the term may be applied to simple solar hot water panels, it is usually used to denote more complex installations. There are various types of thermal collectors, such as solar parabolic, solar trough and solar towers. These type of collectors are generally used in solar power plants where solar heat is used to generate electricity by heating water to produce steam which drives a turbine connected to an electrical generator.
The plant uses 1,255 heliostats (motorized mirrors) to reflect sunshine onto a fixed focal point. The heliostats follow the sun's path throughout the day to catch maximum rays.
With a surface area of 1,291 square feet each, the massive mirrors working together focus over a million and a half effective square feet of sunlight on the apex of the tower. It gets hot. Very hot. That heat energy can be used to boil steam to turn turbines, or stored for later use.
What to do when the sun's not shining has forever been solar power's nemesis. While we can't alter the sun's behavior, we can store its power for later use. Electrical batteries have offered somewhat of a solution toward this end, but they are expensive, tough on the environment and impractical for utility-scale power storage.
Current technology can store solar-generated heat for up to seven hours, and the US National Renewable Energy Laboratory is looking forward to stretching that to 12 hours.
In the circumstances, Concentrating solar power (CSP), the technology adopted in the Spanish plant, is poised to take the solar industry by storm, offering all the benefits traditionally ascribed to solar - clean, renewable, etc. while effectively dealing with the storage-related problems.
CSP captures and concentrates the sun's rays to boil steam, and in turn uses the pressure of that steam to turn a turbine and produce electricity. It's far easier and more efficient to store the sun's energy as heat than electricity. The heated fluid can be trapped in insulated storage tanks and then called upon and used to boil water long after stars have begun to shine, writes Sean Sullivan on Clean Technica.com
Concentrating solar power has the potential muscle to compete with fossil fuels in terms of megawatt output, he predicts.