A stirling solution for combined heat and power

Already ridding an extensive line of distributed generation products under its energy|now brand, DTE Energy Technologies (DTE Tech) has expanded the renewable side of its lineup with the introduction of the ENX 55 energy system. The 55 kW cogeneration package is powered by a Stifling engine fueled by natural gas, propane, flare gas, methane, wood gas, biogas or, in its heat-fired version, heat produced from industrial processes.

"The way it (the ENX 55) is being employed today is in both CHP (combined heat and power) and power only packages," said Mark Fallek, vice president and chief marketing officer for the Farmington, Mich., company. "The applications that we think make sense are employing it in places where there is free gas--things like landfills or digesters at wastewater treatment plants or agricultural operations that produce methane, which can then be burned to produce power.

"In the agriculture arena, more and more digesters are being used to breakdown manure, making methane and carbon dioxide. We can take that gas and burn it in a Stirling engine for power as well as use the waste heat to keep The digesters warm. Digesters for these biogas applications need to be kept at 100[degrees]F to keep the anaerobic bacteria alive using the hot water. So it's a good marriage."