Salinity gradient solar ponds collect and store solar energy. Solar energy is absorbed in the lower level of the pond and is stored as thermal energy. The thermal energy can then be used for process heat ,space heating, desalination and /or generation of electricity
Solar ponds have an advantage over other solar energy collection methods in that the solar pond is both a collection and storage device. This allows the pond to continue providing energy even when the sun is not shining.
Another View
This is another view of the Solar Pond
Solar ponds have a low coast per unit area of collector. They can be easily constructed over large areas enabling the diffuse solar resources to be concentrated on a grand scale.
Solar ponds address two environmental issues: First heat energy is provided without burning fuel, thus reducing harmful pollution. Second, when coupled with desalting units, solar ponds can be used to purify brackish or salt water, and then the pond itself can become the receptacle for the brine waste product.