IBM has taken ideas about cooling supercomputers and helped apply them to a photovoltaic system for capturing solar energy—which could be used to power a server, in return.
A three-year, $2.4 million (2.25 million CHF) grant from the Swiss Commission for Technology and Innovation has been awarded to scientists at IBM Research and Airlight Energy (the latter a supplier of solar-power technology), along with ETH Zurich and the Interstate University of Applied Sciences Buchs NTB. Their combined goal: research and develop a high-concentration photovoltaic thermal (HCPVT) system.
IBM and its partners believe they can take 80 percent of the incoming radiation and transform it into useful energy, including taking as much waste heat as possible and repurposing it; the companies believe that waste heat could be used for thermal-powered water desalination in arid climates. In theory, solar power stations of this type could be placed in harsh deserts such as the Sahara, where the presence of desalination plants would also help ensure that the locals maintain them.
The prototype relies on a large parabolic dish attached to a motorized tracking system, which positions it to optimally capture the sun’s rays. The solar energy reflects off the mirror onto an array of photovoltaic, 1 cm-by-1 cm chips, which can convert between 200 and 250 watts per eight hours of sunshine. The entire receiver combines hundreds of chips and provides 25 kilowatts of electrical power.
As each chip receives the sun’s rays, however, the solar energy heats it tremendously—enough so that it must be somehow cooled or risk damage from the sun’s rays. To handle this issue, IBM and its partners fell back on the same micro-channel, liquid-cooled receivers used in the IBM Aquasar system that powers the SuperMUC supercomputer in Germany.
The liquid coolants pass within a few tens of micrometers of the chip, absorbing the heat and drawing it away, which IBM considers ten times more effective than passive air-cooling. The coolant maintains the chips almost at the same temperature for a solar concentration of 2,000 times and can keep them at safe temperatures up to a solar concentration of 5,000 times.
“We plan to use triple-junction photovoltaic cells on a micro-channel cooled module which can directly convert more than 30 percent of collected solar radiation into electrical energy and allow for the efficient recovery of an additional 50 percent waste heat,” Bruno Michel, manager, advanced thermal packaging at IBM Research, wrote in a statement. “We believe that we can achieve this with a very practical design that is made of lightweight and high strength concrete, which is used in bridges, and primary optics composed of inexpensive pneumatic mirrors—it’s frugal innovation, but builds on decades of experience in microtechnology. ”
IBM said that the cost of producing the solar energy would be about 10 cents per kilowatt-hour, compared to about between 5 to 10 cents per KWh at coal-fired plants.
IBM and its partners intend to pass the heat through to a heat exchanger, which could be used to power the desalination plant. In this way, a system could provide 30-40 liters of drinkable water per square meter of receiver area per day, while still generating electricity with a more than 25 percent yield, or two-kilowatt hours per day.
For now, it sounds like the partnership plans to put the energy it collects back into the national grid. But the solar power could also be used to power a Microsoft ITPAC—a self-contained server that’s built outside in a container that can withstand searing heat and snow. And wouldn’t these power stations be ideal for IBM’s own “superman servers” for the Square Kilometer Array radio telescope? IBM may be capturing all of the pieces for ruggedized outdoor servers.