High-enthalpy resources exist worldwide only in a few regions. In other regions adapted power plant technologies like Organic-Rankine-Cycle or Kalina-Cycle are necessary because of the low geothermal temperature. In general, these plants have to be optimized overall. Furthermore, they have a high auxiliary power demand. Therefore, with German boundary conditions gross process efficiencies of nearly 14% can be reached today but the overall plant efficiency is lower 10 %.