User-friendly Geological Data Tools and Guidelines Pave the Way for Geothermal Heat Supply in Lower Saxony, NW-Germany

Abstract

During the last decade, Germany has experienced a boom in the field of shallow geothermal energy. To date (end of 2013), more than 260,000 geothermal heating systems have been installed in Germany. The German government encouraged the owners of buildings to choose a form of renewable energy by implementing the German Act on the Promotion of Renewable Energies in the Heat Sector (in German: Erneuerbare-Energien-Wärmegesetz, EEWärmeG). The motivation behind this is the turnaround in energy policy, called Energiewende. In order to help people to decide whether shallow geothermal energy is the adequate form of renewable energy for their purpose, the geological surveys of Germany provide essential data for geothermal projects. The State Authority for Mining, Energy and Geology, Lower Saxony, has developed several freely available tools: a mapserver application, the online tool “geothermal energy – is it possible at my place?” and a guideline for geothermal heat utilization. The most frequently used tool is the mapserver, called NIBIS. It is available via internet and displays not only data about geothermal energy, but also relevant geological data such as geological and hydrogeological maps and well data. The tool provides guidance regarding legal restrictions related to shallow geothermal energy, and also underground information about the expected potential of geothermal plants. The second internet tool is called “geothermal energy – is it possible at my place?” and provides an answer to that question for any specific location in Lower Saxony. The tool requires only limited input data by the user about the location, and either the energy consumption or the type of building, to provide an estimation of the dimensions as well as the anticipated costs of installing the subsurface geothermal system. Both unique tools are available as free applications for smartphones and tablets. Another important element is the guideline for geothermal heat utilization in Lower Saxony. This document represents a road map that addresses different players, e. g. drilling companies and licensing authorities, operating in the shallow geothermal energy market. It describes the technical and scientific fundamentals as well as the licensing procedure of the local water authorities. Depending on the proposed location of a new geothermal system, the site can be located in a permitted, conditionally permitted or prohibited region for the use of shallow geothermal energy. The resulting recommendations for each of these regions are described in the guideline. With the help of these two online tools and the guideline, an increasing number of landlords in Lower Saxony are choosing geothermal energy as the main source for their heating and cooling systems. This clearly demonstrates that the installation of geothermal systems is a very successful approach and an effective instrument that contributes to reach the goals of the Energiewende.