By Michael Graham Richard
23 April 2013
(TreeHugger) – Concentrating the sun's ray onto solar photovoltaic (PV) modules requires walking the fine line between optimizing power output and not literally melting your very expensive super-high-efficiency solar cells. A team led by IBM Research seems to have found a way to push back the line. They have created a High Concentration PhotoVoltaic Thermal (HCPVT) system that is capable of concentrating the power of 2,000 suns onto hundreds of triple junction photovoltaic chips measuring a single square centimeter each (they even claim to be able to keep temperatures safe up to 5,000x). The trick is that each solar PV cell is cooled using technology developed for supercomputers; microchannels only a few tens of micrometers in width pipe liquid coolant in and extract heat "10 times more effective than with passive air cooling."
The beauty is that this heat is not just thrown away. This system gets useful work out of it. So while the PV modules are 30%+ efficient at converting the sun's light into electricity, another 50% of the sun's energy is captured as heat and can then be used to do things like thermal water desalination and adsorption cooling. This means that the system is capable of converting around 80% of the collected solar energy into useable energy (though the electricity is of course more useful than the thermal energy). [more]