PORTLAND, Ore. — IBM Research (Zurich) and Airlight Energy SA (Biasca, Switzerland) aim to boost the output of high-concentration photovoltaic cells by as much as 10-times by using micro-fluidic water cooling with commercial triple-junction photovoltaic cells. The resulting 25kWatt 50-foot-wide dish-based concentrated solar power stations will be constructed in Biasca and Rüschlikon Switzerland under a three-year $2.4 million grant from the Swiss Commission for Technology and Innovation. Also working with IBM and Airlight Energy on the project will be the the Swiss Federal Institute of Technology (ETH, Zurich) and the Interstate University of Applied Sciences (Buchs).
"We are using the same water-cooling technology IBM developed for high-performance computers to attain a 10-fold decrease in the thermal resistance of the photovoltaic cells," said Bruno Michel, manager of advanced thermal packaging at IBM Research. "As a result, we have demonstrated that commercially available triple-junction photovoltaic cells--which cover almost the entire spectrum of solar energy with 80 percent efficiency--can now handle from 2000-to-5000 times concentrated solar power from the sun, compared to 300-to-500 times when air-cooled."
The higher concentration of solar energy is produced by arraying 36 mirrors across the 50-foot dish that tracks the sun as it moves to continually aim their high-energy beams on an array of over a hundred triple-junction photovoltaic cells mounted on the central gantry, each of which generates from 200-to-250 watts. Without IBM's water cooling, the concentrated energy from the solar beam could produce temperatures high enough to vaporize the chips. Instead, IBM's micro-fluidic substrate conducts the heat away from the photovoltaic cells with a hierarchical arrangement of water channels.
High Concentration PhotoVoltaic Thermal (HCPVT) system under development by IBM and Airlight Energy concentrates sun onto hundreds of microfluidic liquid-cooled triple junction photovoltaic cells to provide 25 kilowatts of electrical power.
SOURCE: Rendering by Airlight Energy
Click on image to enlarge.
And just as IBM's water-cooled data centers make use of the heat from the water heated by its chips--to heat adjacent buildings--the solar power stations will be adapted to applications that make use of its heated waste water. However, since most of the envisioned installations will be in warm climates, IBM is experimenting with using the warm water in absorption refrigeration systems that substitute for conventional air conditioners, and for thermal water desalination plants.
The final goal of the project is to produce electricity from solar energy the cost of which is on par with coal-fired generators, about 5-to-10 cents per kilo-Watt-hour (kWh). By using inexpensive concrete and pressurized metallic foils, the cost of commercial dishes should drop to about $250 per square meter--three-times lower that existing photovoltaic concentrators today, according to IBM.