Micro gas turbines have been around since around 1990. In addition to the low output in the range between 30 and 500 kW, the turbines are characterized by simple technology. The lower turbine inlet temperature allows uncooled blades. To increase efficiency, microturbines use recuperators that preheat the compressed air with the heat from the exhaust gas before it enters the combustion chamber. This makes efficiencies of around 30 percent possible. The largest manufacturer at present is the US company Capstone. Other manufacturers include Flexenergy, Turbec and Elliot.
Flex Energy MT250 module (Gammel Engineering)
Flex Energy MT250 components (Gammel Engineering)
Factory acceptance in the USA by Gammel Engineering
Capstone 65 kW (Gammel Engineering)
Capstone 200 kW (Gammel Engineering)
Micro gas turbine module CPS (Dürr)
Sources:
Wikipedia http://de.wikipedia.org/wiki/Gasturbine
Flex Energy http://www.flexenergy.com/
Dürr http://www.durr-cleantechnology.com/