Low-Temp Waste Heat Company Snares $2.6M

What’s the main problem with trying to exploit waste heat in factories to generate electricity? The high temperatures required, says Bill Olson, vice president of business development at ElectraTherm, which has released a low-temperature waste heat device called the Green Machine. ElectraTherm said it raised $2.6 million today.

Low is a relative term. The system requires air that’s heated to about 200 to 400 degrees, but that is less than half the temperature required by conventional systems. The Green Machine takes hot air and runs it through a heat exchanger. On the other side of the heat exchanger is a volatile refrigerant. The heat converts the refrigerant from a liquid to a solid—that creates pressure inside the refrigerant tubes, which is then exploited to turn a turbine. In a sense, you have three technologies in one: waste heat capture, heat exchangers and pressure-driven turbines.

ElectraTherm’s standard Green Machine can provide 50 kilowatts of power and several can be strung together. Larger units are also available, but the company will not likely cross the 1 megawatt line. After that, other alternatives such as fuel cells begin to undercut its advantages.

The Green Machine costs over $100,000 but payback can occur in the first few years.