This New Device Could Convert Wasted Heat Into Power
Using excess heat might be a way to harvest $1 trillion worth of lost energy.
Our civilization's seemingly insatiable hunger for more and more energy has driven us to burn massive amounts of fossil fuels, whose emissions are driving us toward catastrophic climate change. But here's an even more disturbing fact. We waste much of the energy that's produced from those fuels, in the form of excess heat. Power plants, for example, typically lose 65 percent of the energy they produce.
But imagine if we could capture that lost energy and use it, through thermoelectric devices that convert heat into electricity by exploiting the flow of electrons from a warmer spot to a cooler one.
A 7-year-old company called Alphabet Energy is working toward accomplishing just that, according to the publication Berkeley Engineer. Alphabet, which was founded by UC Berkeley alumnus Matt Scullin and Peidong Yang, a professor and faculty scientist at Berkeley Lab, is producing what the publication hails as "the most efficient thermoelectric devices ever made for waste-heat recovery."
As a Alphabet Energy's website explains, the company's devices use silicon or tetrahedrite, both low-cost, highly-efficient thermoelectric materials.
The goal is to harness combustion exhaust from sources ranging from cars and trucks to power plants.
"Waste heat is everywhere," Scullin said. "It is an absolutely huge opportunity."
Scullin has calculated that a mind-blowing 208,000 terawatt-hours are lost as heat worldwide each year. (A terawatt is equal to 1 trillion watts.) If we could recover even 5 percent of that loss, at a rate of 10 cents per kilowatt-hour, the savings would be worth about $1 trillion annually.
The industry group Heat Is Power has calculated that using waste-heat recovery at U.S. power plants could produce enough electricity to power 11.4 million homes.
Alphabet Energy has also developed a way to use heat from excess natural gas flared at North Dakota's Bakken shale play to generate electricity. Here's a YouTube video explaining how that device works.
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