Highly concentrating parabolic channel collectors can provide energy on temperature levels which is suited for joining fossil-fired power stations in the area of feedwater preheating. The reduced amount of bleeder steam, resulting from this, needed for preheating, can be expanded in the turbine instead and thus increase the efficiency of the turbine. This solar support can be used for the saving of fuel or for the generation of peak loads. With the aid of simulation calculations, the annual energy yield or the fuel saving, respectively, gained with a solar plant feeding the preheating area was calculated For two exemplary power stations in Southern Spain and Arizona, USA.