A three-year, US$2.4 million grant is to aid scientists to develop an affordable PV system capable of concentrating solar radiation 2,000 times and converting 80% of the incoming radiation into useful energy.
The Swiss Commission for Technology and Innovation has awarded scientists at IBM Researc; Airlight Energy, a supplier of solar power technology; ETH Zurich (Professorship of Renewable Energy Carriers) and InterstateUniversity of Applied Sciences Buchs NTB (Institute for Micro- and Nanotechnology MNT) to research and develop an economical high concentration PV thermal (HCPVT) system.
The prototype HCPVT system uses a large parabolic dish, made from a multitude of mirror facets, which are attached to a sun tracking system. The tracking system positions the dish at the best angle to capture the sun's rays, which then reflect off the mirrors onto several liquid cooled receivers with triple junction PV chips – each 1x1cm chip can convert 200-250 watts, on average, over a typical eight hour day in a sunny region.
“We plan to use triple-junction photovoltaic cells on a micro-channel cooled module which can directly convert more than 30% of collected solar radiation into electrical energy and allow for the efficient recovery of an additional 50% waste heat,” said Bruno Michel, manager, advanced thermal packaging at IBM Research.
“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.”
“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.”
With such a high concentration and a radically low cost design scientists believe they can achieve a cost per aperture area below US$250 per square meter, which is three times lower than comparable systems. The levelized cost of energy will be less than US$0.10 per kWh. For comparison, feed in tariffs for electrical energy in Germany are currently still larger than US$0.25 kWh and production cost at coal power stations are around US$0.05-10 per kWh.
A prototype of the HCPVT system is currently being tested at IBM Research – Zurich. Additional prototypes will be built in Biasca and Rueschlikon, Switzerland as part of the collaboration.