A microturbine is a small rotor-type turbine engine, approximately the size of a refrigerator, with energy outputs of 25 kW to 500 kW that is used as an alternative method of power generation. Microturbines use fan blades to compress air or air-fuel mixes, which are then combusted to generate both electric and thermal energy. Microturbines are usually powered by natural gas, but can also be powered by biogas, hydrogen, propane or diesel.
Microturbines are mainly used in commercial applications; however, residential use is feasible. In addition to being highly efficient, these light weight units have low maintenance costs and have low emissions.
Microturnbines can not currently earn the ENERGY STAR label.
More information: National Institute of Building Design