Google has been stacking their chips in the solar thermal sector for quite some time, investing in two companies — eSolar and BrightSource. Meanwhile Google has been funding its own R & D investigation into ways that will reduce the cost of this promising but costly renewable energy technology.

On Friday Google announced that it had created a working prototype of a new low-cost solar mirror which could be ready for manufacturing in as little as a year.

In solar thermal, the heliostat — an array of mirrors which focuses onto a single point to generate steam power — is the most costly component, so Google has been testing innovative materials for both the reflective surface of the mirrors and the substrate to which they are adhered.

The result, according to the company's green tech guru Bill Weihl, is a new mirror that could potentially cut costs by as much as 50 percent, making solar thermal competitive with coal and beating all other sources of renewable power. It would also give Google a new product to sell to two solar companies which it partially owns.

Considering Google's historic leadership in conjuring trillion dollar industries out of thin air, investors and energy companies might want to get into the solar thermal game before it gets even hotter.

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