Conditions for the Utilisation of Low-Enthalpy Hydrogeothermal Resources in Germany - an Interdisciplinary Approach

Abstract

The utilisation of geothermal energy is regarded as a promising possibility to cover a substantial part of mankindís increasing energy demand. Today the hydrogeothermal resources used in Germany for low temperature heat supply cover only a small part of the energy demand. A more widespread application is limited by a variety of factors of different nature and scale. Regional geological settings (supply) and consumer structures (demand) are well known with some degree of uncertainty and technical solutions for the exploitation of different resources are available. Because of the mentioned uncertainties reliable predictions for heat generation costs are difficult to obtain. They depend on very detailed location specific information, as the technological layout is strongly affected by the above mentioned parameters and their interaction. Within an interdisciplinary working group of geoscientists, engineers, and economists the following topics and the coupling between various parameters was investigated: - - - - - - energy-ecological and energy-economical analysis. The investigations contribute to a better general understanding about mechanisms and processes during the exploitation of hydrothermal resources. Recommendations for the layout of geothermal heating plants and their operational regimes are derived. The tools developed show, that the utilisation can be competitive with the fossil fuel combustion of their alternatives. Environmental effects associated with the later are avoided to a great extent.