Posts Tagged solar thermal

Solar Power in the Spanish Night

Posted by on Sunday, 18 April, 2010

Recently some Spanish business organizations have questioned the reports of Spanish companies that reported solar power production at night. They thought it might be fraud, although there are ways of generating solar power at night.

An article by Business Week reported this story. The business group ASIF demanded an investigation. There actually are ways to produce solar power at night. According to the University of Central Florida, solar power can be produced at night. Students at the school found a method of storing solar energy in wax. Since the wax remains liquid even after the sun sets, it continues to hold heat energy that is used to heat hot water.

It’s not just wax that can be used to store solar energy at night. Researchers at Yale University have reported a method of storing solar energy using molten salt. Surprisingly enough, this method of storing solar energy in salts such as potassium nitrate is used in Spanish solar thermal plants, according to the Yale article. Since this technology is already available in Spain, the solar power companies in Spain have already implemented methods of using solar power at night. This information should alleviate the concerns of Spanish businesses who feel they are being charged for solar energy at night and being provided energy from petroleum based sources, by demonstrating that this method is already in common use in Spain.

Some of the Spanish solar thermal plants are very large. The University of Montana shows an array of hundreds of mirrors which reflect the solar energy. The mirrors can heat a substance to several hundred degrees Celsius. It is important to select the correct substance to contain this energy. A wax that melts easily at a hundred degrees may boil away if heated too hot. It’s also necessary to select a substance that contains a large amount of heat energy. Water is capable of storing large amounts of energy, although it does boil or evaporate if exposed to too much heat. The University of Montana suggests that graphite compounds are another potential material for storing the heat energy in solar thermal plants.