A new alloy could be a source of green energy

Researchers at the University of Minnesota have discovered a material that can turn waste heat sources such as a car's exhaust into enough electricity to charge a battery in a hybrid car. With better machines and materials, scientists could unlock America's hidden power source.
Written by Boonsri Dickinson, Contributing Editor

About sixty percent of energy produced is wasted as heat. When you rev up your car engine, the heat is emitted into the atmosphere and lost forever. Researchers at University of Minnesota demonstrated in their lab that an alloy can convert heat directly into electricity. If commercialized, it could use waste heat from a car's exhaust to charge a hybrid car's battery, scientists say.

"This research is very promising because it presents an entirely new method for energy conversion that's never been done before," Minnesota's professor Richard James said in a statement.

The new alloy is known as Ni45Co5Mn40Sn10, a mix of nickel, cobalt, manganese and tin. Its properties are across the board: elastic, magnetic and electric. It starts out as a non-magnetic material. But when the material is heated up, it becomes magnetic and can produce electricity in a nearby coil. The study was published in the journal Advanced Energy Materials.

Minnesota researchers say, they are also working with colleagues on creating a thin film of the alloy material, to turn waste heat emitted from computers into electricity.

We waste so much energy, yet waste heat is an untapped source of energy that could make processes much more efficient. Our laptops, nuclear power plants, chemical factories and cars all contribute to this wasted heat. That's why there's so much interest in using that heat - wisely.

A more mechanical approach

As I mentioned before, researchers at Purdue University are working with General Motors to create thermoelectric generators (TEGs) to turn waste heat directly into electrical energy for cars. The idea is to use the heat from the car engine’s exhaust to generate electricity. The prototype - which is a small metal chip - will basically hook up to the exhaust system and tap into heat coming from the gases.

So much heat is lost during the manufacturing process. But it can be captured at the factory site or sold to the power grid. Founder of Recycled Energy Development, Tom Chasten, told Businessweek:

"There's been some awakening by policy makers that energy we get from waste is as clean as wind or solar or geothermal. Through cogeneration [generating electricity and heat from a single fuel source] and capturing waste heat a factory already emits, we could cut CO2 emissions by about 20 percent and save about $100 billion a year."

Norwegian officials, however, have taken recycling waste a little too literally. On the flip side, residents can feel productive in the bathroom, knowing their waste is powering a new fleet of buses.

via Popular Science and University of Minnesota

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