Scanning transmission electron microscope image of a nickel-platinum composite material created at The Ohio State University. At left, the image is overlaid with false-color maps of elements in the material, including platinum (red), nickel (green) and oxygen (blue). Imaging by Isabel Boona, OSU Center for Electron Microscopy and Analysis; Left image prepared by Renee Ripley. Photo courtesy of The Ohio State University.
Machines like car engines produce a lot of heat, which is wasted energy that just gets released into the atmosphere. Finding ways to utilize that “waste heat” would be a huge step forward in efficiency, and now a team at The Ohio State University is working on doing exactly that.
Back in 2012, the same researchers found a way to utilize the energy of waste heat to generate electricity, but the materials they used—platinum and nickel—were prohibitively expensive.
Their new take on the same process uses a lot less platinum, just flakes of it mixed in with the much cheaper nickel, and it can be made thicker. The combination means that it actually has some more practical applications. By changing the ratio of nickel to platinum, they’ve reduced the voltage output, but by making it possible to use more of the material, it generates more electricity overall.
By using thicker material in these recent tests, the researchers have been able to replicate the types of components we’ll be seeing more of in electronics. This means that they can be used alongside car or jet engines for example, to use the waste heat to generate electricity, which could subsequently be used to power other parts of the vehicle.
It might also be possible to apply the same idea to other, larger heat-generating devices and fixtures. Waste heat isn’t just an issue in cars and jets, it’s a fundamental aspect of thermodynamics and something that we could be putting to use if we had a better understanding of the mechanics involved.
“Over half of the energy we use is wasted and enters the atmosphere as heat,” says study co-author Stephen Boona. “Solid-state thermoelectrics can help us recover some of that energy. These devices have no moving parts, don’t wear out, are robust, and require no maintenance.”
The research being done by the Ohio State engineers is a step in the right direction. The ability to produce electricity as a by-product of other actions could be a huge step toward greening energy production, allowing us to produce more electricity without having to burn fossil fuels.
