The key to increasing solar performance appears to be going small … very small … nanotechnology.

Researchers at UConn’s engineering campus have developed incredibly small antennas capable of harvesting over 70% of the sun’s energy, converting it to useful electricity. The best existing commercial solar-electric [photovoltaic] panels can convert about 20% of the sun’s incoming solar radiation to electricity. Cost of the panels and their low efficiencies long have been tough roadblocks to the wide-spread commercialization of solar energy systems. The folks at UConn are hot on the trail to improve solar economics.

The tiny antenna developed under the guidance of Dr. Brian Willis and his team at UConn are known as “rectennas” because they can absorb the electromagnetic spectra and rectify it directly for use. All this absorption and rectification of solar energy occurs between tiny electrodes spaced at distances 30,000 times smaller than the diameter of a human hair. That is Dr. Willis pictured above-holding an antenna assembly. shown below is an illustration depicting the nano-sized technology–the antenna and rectification components.

The rectennas are able to convert both the visible portion of sunlight as well as the infra-red component. Traditional solar panels today can only absorb the visible portion of sunlight. Just for the record, of the solar energy coming to planet earth, about 45% we see as visible light; 45% is in the infra-red part of the spectrum, which we perceive as heat; and 10% is ultra-violet in nature – the high energy part that gives us sunburn. The rectennas can be made, or tuned, to absorb any part of the spectrum, thereby radically increasing overall panel efficiency and lowering cost.

This is big news indeed and something Thomas Edison would have loved. He was a solar enthusiast long before folks were talking about solar applications for buildings-see his quote below.
Go UConn!

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