Efficient Geothermal-Fossil Hybrid Electricity Generation: Geothermal Feedwater Preheating in Conventional Power Plants

Abstract

Hybrid steam power plants with geothermal feedwater preheating enable the utilisation of geothedcs in electricity generation in Germany. In order to estimate the potential of geothermal-fossil hybrid power plants with geothermal feedwater preheating, we examine the application of this concept in the examples of two modem power plant assemblies. In addition, energy output and economic efficiency calculations will be compiled for this concept utilising the thermal water data of an existing geothermal heating installation. The process of geothermal feedwater preheating as a means of improving performance forms both an alternative and an extension to the electricity generation methods based on renewable energy, for example photovoltaics or wind power, which tend to be high in costs and/or low in availability. An electricity cost of around 300 DM/MWh appears to be attainable. In countries with the appropriate prerequisites, a considerable benefit in efficient electricity generation and environmental protection can be expected with this concept.