The turbine used was a prototype of an Ergion steam screw with a capacity of 10 kWe, which is operated at a temperature between 170 and 220 °C with a peak efficiency of 11 % and average electrical efficiency of 7 to 8.5 %. A turbine of 2 MW size may reach 19 % efficiency, while a 5 MW turbine already reaches up to 26 % and 50 MW units may reach nearly 40 % [14, 15]. The difference is that a steam screw can be operated at 170 °C, while a turbine needs 330 °C and good steam quality to reach the above mentioned values. Unfortunately there is no commercial small scale electricity generating units in the market yet. Several institutions are working in this field to develop solutions, but only a few are installed until today. If suitable engines are available, than small scale solar trough installations are going to be seen in larger numbers in sunny regions around the world.