A team of researchers at MIT is working on a system that can supply solar energy for 24 hours straight by storing heat in containers of molten salts. A Spanish company, Torresol Energy, has implemented a similar system before, but the MIT team is working to lower the costs associated with installation, operation and maintenance. The goal is to help smaller towns be able to separate themselves completely from the electrical grid and rely solely on clean energy.
Concentrated solar power technology has previously been used through a large array of mirrors concentrating sunlight on a tower. Combined with molten salt, it produces energy that is used to generate steam from water, which forces a turbine to rotate and thus create electricity. This type of system, however, is not commercially feasible because of the expensive plumbing and pumps that are needed.
The MIT team developed a ground mounted, heavily insulated tank that combines the functions of heating and storage. This system significantly cuts down on plumbing and maintenance costs because an array of mirrors positioned above the tank concentrates sunlight on a narrow opening at the top. They have been able to achieve temperatures of more than 900 degrees Fahrenheit. Over the long term, according to the team, this method would be inexpensive to maintain compared to similar systems where sunlight is focused upward toward a tower.
So far, the MIT team has only carried out small-scale tests on its system. Larger tests are obviously needed to determine if the system would be feasible for commercial use. But it is still an example of the continuous work being done to make solar power even more viable for mass consumption.