The geothermal plants constructed between 2005 and 2010 showed that the actual efficiency of the plant is controlled by the interaction of the individual underground and surface components. It was therefore to be assumed that the overall efficiency could already be significantly increased in the planning phase with coordinated optimization measures for surface and underground components.

The aim of the joint research project of ERDWERK and the FH Munich (University of Applied Sciences) was therefore to investigate the economic efficiency as well as the ecological and energetic efficiency of geothermal plants for heat supply at four locations in southern Germany and to improve the planning of future plants.

In the project (FKZ 0325262A) funded by the BMWi (Federal Ministry of Economics and Energy), ERDWERK focused on drilling and pumping with the recording and evaluation of site-specific plant and operating parameters. In the investigations these were compared among themselves in order to establish a benchmark. In addition, a modelling tool was developed in Matlab to simulate the primary circuit. With the help of simulations carried out at the FH, the previously unknown friction losses in the so-called "perforated liner" could be evaluated.

To date, when planning new plants, the characteristics of individual plants that have been surveyed in this R&D project are repeatedly referred to.

The joint results were summarized in a planner's and operator's manual (Planer- und Betreiberhandbuch [german]).