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Nanotechnology turns heat into electricity

Kevin Bullis of Technology Review reminds us of something we should all remember from thermo class:

Inside fossil-fuel and nuclear-power plants, as well as in cars and trucks, the lion’s share of energy in fuel is wasted as heat rather than converted into electricity or mechanical power. But the search for a practical material that can convert at least some of this waste heat into electricity has been long and frustrating.

UC Berkeley nanotechnology researchers Rachel Segalman, Arun Majumdar, and team to the rescue:

The researchers trapped a few molecules between a sheet of gold and the ultrafine gold tip of a scanning tunneling microscope, which is so sharp it can end in a single atom. They heated up the gold surface and measured, via the microscope tip, the voltage that was created…The results confirmed that the organic molecules could indeed be used to generate electricity from heat…The research is only the first step, the researchers say, and, because much work remains, applications will be many years away.

If all goes well, though, so-called thermoelectric devices based on the molecules could prove to be an important source of power–and a way to reduce greenhouse-gas emissions by making far more efficient use of fossil fuel. “Ninety percent of the world’s electricity is generated by thermal-mechanical means,” says Arun Majumdar, professor of mechanical engineering at UC Berkeley and another researcher on the project. “And a lot of the heat is wasted. One and a half times the power that is generated is actually wasted.”

For an overview of nanotech by Arun Majumdar, published in 2001 but still worth reading, see “Not Without Engineering” in Mechanical Engineering magazine, mentioned here on Nanodot earlier. About flagellar motors, he writes:

Biologists have investigated these motors. If, however, one looks at them from the engineer’s viewpoint, one could envision isolating the motors to propel nanoscale robots…

This group’s current results encourage us in our belief that gaining control of matter “all the way down” to the molecular level can make a huge, positive difference to society. (Credit: Billy Harvey) —Christine

3 Responses to “Nanotechnology turns heat into electricity”

  1. James Aach Says:

    One item of interest when discussing conversion of waste heat to electricity is that in the standard electric generation steam cycle of boiler/reactor to turbine to condenser, the prompt removal of waste heat from the condenser is a requirement of the cycle itself, and is done on a massive scale in modern power plants. Often the waste heat removal is via a continous flow path using cooling towers to prevent too much waste heat rejection to the environment. Any removal of the waste heat in this case by converting it to another power source (versus cooling towers alone, etc.) would of course be very useful, but for application on a large scale in this case it would also have to be a quick, continuous process that is highly reliable. Otherwise, it would just be a minor adjunct (perhaps sitting in the bottom of the cooling towers.) On the other hand, plants which also use large cooling ponds where the heat is dumped without overall environmental impact might provide a better application, as any additional heat removal would be a bonus whose speed wouldn’t effect the primary cycle. Also, if waste heat can be converted, other electric generation methods which may be less reliant on prompt waste heat removal via a recycled coolant but are less efficient with primary energy use (such as a diesel engine, which provides hot exhaust and a lot of engine block heat even with its internal cooling system) suddenly may become more cost effective for electricity generation. Large scale, speed, and reliability would be the key factors in any work in this area.

    For an entertaining inside look at nuclear power, see my novel Rad Decision, free on line at http://RadDecision.blogspot.com and also in paperback.

  2. Mark Lohrmann Says:

    The future is NOW! … This company is already commercial with its heat to electricity microchips!

    http://www.eneco.com/

  3. Mark lohrmann | CartoGraphix Says:

    [...] the Foresight Institute » Nanotechnology turns heat intoInside fossil-fuel and nuclear-power plants, as well as in cars and trucks, the lion’s share of energy in fuel is wasted as heat rather … UC Berkeley nanotechnology researchers Rachel Segalman, … The researchers trapped a few molecules between a sheet of gold and the ultrafine gold tip of a scanning tunneling microscope, [...]

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