High Concentration Photo Voltaic Thermal Systems

On Earth Day, scientists have announced a collaboration to develop an affordable photovoltaic system capable of concentrating solar radiation 2,000 times and converting 80 percent of the incoming radiation into useful energy. The system can also provide desalinated water and cool air in sunny, remote locations where they are often in short supply.

A three-year, $2.4 million grant from the Swiss Commission for Technology and Innovation has been awarded to scientists at IBM Research, Airlight Energy, ETH Zurich and Interstate University of Applied Sciences Buchs NTB to research and develop an economical High Concentration Photo Voltaic Thermal (HCPVT) system.

Based on a study by the European Solar Thermal Electricity Association and Greenpeace International, technically, it would only take two percent of the solar energy from the Sahara Desert to supply the world’s electricity needs. Unfortunately, current solar technologies on the market today are too expensive and slow to produce, require rare Earth minerals and lack the efficiency to make such massive installations practical.

“The design of the system is elegantly simple,” said Andrea Pedretti , chief technology officer at Airlight Energy. “We replace expensive steel and glass with low cost concrete and simple pressurized metalized foils. The small high-tech components, in particular the microchannel coolers and the molds, can be manufactured in Switzerland with the remaining construction and assembly done in the region of the installation. This leads to a win-win situation where the system is cost competitive and jobs are created in both regions.”

According to Bruno Michel, manager, advanced thermal packaging at IBM Research, the group intends 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.

“We can achieve this with a practical design 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,” added Michel.

With such a high concentration and a radically low cost design scientists believe they can achieve a cost per aperture area below $250 per square meter, which is three times lower than comparable systems. The levelized cost of energy will be less than 10 cents per kilowatt hour (KWh). For comparison, feed in tariffs for electrical energy in Germany are currently still larger than 25 cents per KWh and production cost at coal power stations are around 5-10 cents per KWh.

Scientists envision the HCPVT system providing sustainable energy and potable water to locations around the world including southern Europe, Africa, Arabic peninsula, the southwestern part of the United States, South America, and Australia. Remote tourism locations are also an interesting market. A prototype of the HCPVT system is currently being tested at IBM Research – Zurich.