IBM increases solar efficiency with supercomputer cooling system

Ars Technica : At IBM’s laboratory in Zurich, Switzerland, Bruno Michel and other researchers have adapted the cooling system from the 6-teraflop Aquasar supercomputer for use with concentrated photovoltaic (CPV) solar power generators. They claim to have increased the efficiency of the CPV collector from 30% to 80%. CPV systems use parabolic dishes to reflect light onto a photovoltaic cell. The focused sunlight allows for relatively high-efficiency energy generation from small photovoltaic cells. Every 1-cm ² cell converts 30% of the solar energy into electricity, averaging 200 to 250 W. The other 70% of the solar energy, however, is lost as heat. To reduce the heat loss, the researchers have adapted the cooling system from Aquasar, which uses 50- to 100-μm channels that carry water extremely close to the heat source to cool it. The thermal energy absorbed by the water means that another 50% of the incoming solar energy can be put to use in a number of waysâmdash;from heating or cooling buildings to water purification. Michel’s group has built a 4-cm ² collector prototype and hopes to be able to scale it up to a 100-m ² dish with a 25-cm ² collector that would provide 25 kW of electrical power and 50 kW of thermal power.