IBM Researchers have built a low-cost prototype solar dish that produces electricity and generates heat for desalination or cooling. IBM got the idea for the solar dish from the water cooling technology used in its high-end computers.
The Swiss Commission for Technology and Innovation has provided $2.4 million worth of funding to IBM, Swiss researchers, and the Swiss company Airlight Energy. This kind of technology is atypical for IBM, so experts are unclear about how it will be commercialized ultimately. Experts do know, however, that the system, a high-concentration photovoltaic thermal (HCPVT) system, will be cost-effective.
Conventional parabolic solar dishes produce heat by using concentrated sunlight. The heat is then transferred to a different machine or used to drive a Stirling engine that generates electricity. By tweaking the original design, the dish created by IBM and its partners uses a solar concentrator to shine light on a thin array of highly efficient triple-junction solar cells, producing electricity from sunlight. IBM estimates that just by concentrating the light 2000 times onto hundreds of one-centimeter square cells, the equivalent of 2000 suns, 25 kilowatts of power could be produced by one full-scale concentrator.
Engineers hope to increase the output of the solar cells while making use of the heat the concentrator produces. IBM built a cooling system with pipes only a few microns off the photovoltaic cells to circulate water and carry away the heat. More than 50% of the waste heat is recovered, so the heat is not squandered but instead used for desalination and absorption cooling.