John Langley couldn’t disagree more.
Inside a nondescript garage on Harvard Avenue in Princeton, Langley is polishing up a project that could revolutionize the way we think about renewable energy. His concept is simple in principle: rather than invent a new system of energy use fueled by limited resources, take a conventional system and improve upon it.
  
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He’s talking about heat — specifically, the heat generated by friction and burning gasoline inside engines that radiates outward and dissipates in the wind.
As CEO of Ambient Micro, a company specializing in advanced power supply technologies, Langley directs his focus to the details many innovators overlook. For his most recent project he is engineering a device that converts the heat from engine exhaust into electricity.
Funded by a two-year $750,000 grant from the Small Business Innovative Research Program, a federal program, Langley is testing his theory on small aircraft employed by the military for stealthy surveillance and reconnaissance. Such aircraft are remotely controlled and are also used for monitoring crop cycles and weather patterns.
The plane, a slate shell of Kevlar and carbon fiber, weighs 80 pounds and stretches its wings 13 feet. An insulated pipe feeds motor fumes from the plane’s bowels into a device bolted to the top containing the thermoelectric module of Langley’s design. The device looks like a radiator the size of a breadbox, and sports hundreds of one-inch heat sinks jutting out its sides like fins.
The fins extract heat that accumulates inside the device. That heat is then transferred through the module, which in turn generates an electric charge. Any heat that isn’t converted into electricity flows out the fins on the cold side. Langley said the process is analogous to energy generated by a waterwheel.
“It’s the flow of heat that generates the electric power,” he said. “In our case, the heat is the water, and the thermoelectric module is the wheel that makes the energy.”
It’s a basic concept, Langley says, it just hasn’t been applied in this way before. In fact, it’s been neglected.
By Langley’s calculations, the typical car engine is about 35 percent efficient — meaning 65 percent of the gasoline burns up without boosting thrust or otherwise enhancing the vehicle’s performance.
“So much of the energy in our gas tanks is lost. … This is a way of equalizing the battle a bit,” he says.
His device generates 40 watts of electricity from the aircraft’s 8-horsepower engine. That’s enough energy to power all the computerized systems on board, “so you don’t need to lug around 20 pounds of batteries,” Langley explained.
Further, the module cools the exhaust, a facet the military might find useful.
“If you’re trying to keep from being shot down, it helps to have a cool exhaust stream so there’s no thermal signature,” Langley said.
Following the success of a test run late last month, Langley is working to get more funding from the small business program to spin his prototype into a production-ready model that weighs less and generates more energy.
The technology, once it’s normalized, can be applied to cars, trucks and all sorts of engine-bound vehicles, Langley says.
“If you can extend performance by increasing efficiency of the gas you take off with, you’re ahead of the game. … We’re not generating all the power we could,” he said
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