Scientists are Converting Heat Energy into Electrical Energy

Imagine the ability to efficiently harness the waste heat that constantly surrounds us. Similar to solar cells that converts light energy to electricity, scientists at MIT are developing solid state chips that converts heat energy to electrical energy.

Thermoelectric effect

The ability to convert heat energy into electrical energy has been with us for almost 100 years. Based on a principle called "thermionics" vacuum tube technology was developed that could turn temperature differences into electrical energy. The vacuum tube technology proved to be costly and has been used only for critical military applications involving high temperatures.

The thermoelectric effect has many applications. In addition to generating electricity it can be used to heat or cool objects, and to measure temperature. Refrigeration without compressors is in the future.

Thermal diodes

New solid state devices, called Thermal Diodes, have been developed that replaces the older vacuum tube tech. A race is beginning between teams of scientists to increase the efficiency of the devices. The scientists are also working on cost effective manufacturing methods for the components.

Solid state heat to electrical conversion can be considered green technology. There is no pollution created in the conversion process. Some companies are already looking at the large potential for recycling waste energy.

In some industries the amount of waste energy can be on a large scale. By using manufacturing waste heat it is possible to provide the factory with huge amounts of almost free power.

Thermal to electrical conversion projects

Electratherm has partnered with Gulf Coast Green Energy and created a Green Machine. These machines use solid state technology to convert geothermal brine to electricity. The project is also working on replacing conventional heat pumps with more efficient geothermal pumps based on this new technology.

Associate Professor Peter L. Hagelstein of electrical engineering and computer science, inventor of the solid state technology, has combined efforts with Dr. Yan Kucherov of ENECO, Inc. ENECO is a sponsor of the research along with the Defense Advanced Research Projects Agency. The scientists are looking at the possibility of using the thermal diodes to convert solar energy into electrical energy more efficiently and cheaper than the current solar cell technology.

Conclusion

The conversion of waste heat energy into useful electrical energy should develop into a large industry in the near future. Future equipment that generates waste heat will undergo design changes to make the recovery more efficient and part of the equipment's system.

Elizabeth A. Thomson, "Device could convert waste heat into electricity." web.mit.edu
Josie Garthwaite, "Tapping into the Electric Power of Heat." news.nationalgeographic.com
Zaher Karp, "Green Machines Turn Low Heat Into Electricity." matternetwork.com