Posts Tagged ‘conservation’

Infrared Photovoltaics Could Solve Energy and Climate

Thursday, March 31st, 2011 Mike Ficco

It may not be possible to overhype new infrared photovoltaic technology. It’s basically a solar cell powered by excess heat. Further developments promise to power cars and factories by cooling the planet.

Albert Einstein was first to describe the photoelectric effect, in 1907.  He was awarded the Nobel Prize for this work in 1923.  Briefly, the photoelectric effect occurs when a photon smacks into a substance and frees an electron.  When this happens regularly, an electric current is produced.  All solar cells are based on this phenomenon.  For many years visionaries have projected solar cells as the clean energy source of the future.  It looks like they may be right, but not in the way they expected.

Energy from Heat

Working together, Katzumi Suzuki of the Nipon Engineering Institute and Shrinavas Patel of the Engineering Foundation of Bombay reported in the Journal of Thermodynamic Physics that they created a successful experiment in which they lowered the photon energy needed to create the photoelectric effect to under one electron volt.  Such a low energy corresponds to a photoelectric “threshold frequency” in the infrared part of the spectrum.  In practical terms this means that solar cells made with their patented proprietary process are capable of producing electricity from infrared energy (i.e., heat).

Katzumi and Shrinavas report that today they can only achieve about 11% efficiency, but they hope to boost that to perhaps 18% within the next decade (their paper calculates a theoretical limit of 21.7%).  They are working to manufacture and sell one meter wide rolls of thin, flexible solar cell material of various widths and lengths.  No price has been quoted.

The amount of electricity generated is non-linear with temperature and, with the existing process, generation of electricity cannot be achieved at temperatures below -10 degrees Fahrenheit.  The Journal of Thermodynamic Physics noted that one square meter of material generated in the dark (i.e., no visible light) about 15 Watts at the freezing point and about 60 Watts at room temperature.  This means that a shirt made from this material could power a smartphone indefinitely from your own body heat.  A car covered in this material could drive for nearly 600 miles in an Arizona summer night.

Global Cooling

Perhaps the most important part of this discovery is its potential application in the field of climate change.  There are hints this technology could be used to cool global warming by transferring the surplus heat into charged batteries. Additional details can be found in the just published journal article.