commercialized system of 10 to 100 kW would need at first a suitable small turbine. At this period of time machine producing companies are working world wide to development suitable technologies in the scale between 10 and 200 kW. Until today only prototypes and pre-series are available. Assuming that this technology will be ready within the next years, it has to fit into the market price levels. Such a steam screw should not cost more than 1,000 Euro per kWe installed.