Is Concentrating Sunlight Without Mirrors Possible?

The idea of harnessing solar energy without use of large parabolic mirrors- of course not much argued until recently; is suddenly put on anvil after a study by MIT scientists. Although the research is just a theory, MIT's team is now looking at the possibilities of developing a material which can practically harness solar energy much more than anybody's anticipation.

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Image Credit: MIT news

Brooding upon the idea, for much time, MIT's Research Laboratory of Electronics scientist Peter Bermel and his colleagues fashioned a material which can absorb sunlight and get heated. However unlike other materials, it does not radiate the incident sunlight falling on it back to atmosphere. This is much like green house effect. The behavior is unusual and can be made possible by controlling the microscopic geometry of the material. Such material when subjected to sunlight can attain temperature more than water's boiling point.

Bermel and his team talk of a concept of Angular Radiation. In Angular Radiation, whenever sunrays are incident on the body at a large angle; they are trapped in the material. This is achieved by photonic holes drilled in the sample. The material thus starts operating like that of a black body; the energy hence accumulated can be utilized in producing electricity.

While the efficiency of ordinary solar energy harnessing gadgets is roughly around 10%, the theoretical material by MIT researchers can achieve efficiency of 32-36%. This is really useful as an increase in efficiency of even 1% is really a big quantity. This makes it more than even the most efficient #-Link-Snipped-#. The generation of solar energy through solid state devices called Thermophotovoltaic's date back to 1950s when much of the research was done in this regard. The real challenge before the group is however to actually construct such materials as it would take great efforts to generate microscopic holes of exact geometry. The present study is published in October issue of #-Link-Snipped-# titled #-Link-Snipped-#.

The thermal radiation concept of photovoltaic Resonances although new might prove to be useful in the coming decade which is to see much upheaval in the energy sector. This will be more evident from the space based #-Link-Snipped-#. The material if invented can also find major applications in conventional #-Link-Snipped-# where it might replace Silicon; proving to be more efficient.