Neckarsulm relies on biomass: geothermal energy project on the verge of extinction!

Neckarsulm relies on biomass: geothermal energy project on the verge of extinction!

In Neckarsulm (Heilbronn district), climate-neutral heat sources should be developed using modern geothermal energy. However, recent test drillings on the former AQUAtoll site have shown that this measure is not only too expensive, but also cannot provide the required heat. The drilling reached a depth of 90 meters, although the technical feasibility was proven, but the economic viability was seriously questioned. The ground temperatures are only a maximum of 13 degrees Celsius, while temperatures of 80 to 90 degrees are required for the heating network. This deficit could seriously hinder plans for a comprehensive heat transition in the city, as many buildings are not energy efficient enough to make sensible use of geothermal energy, as SWR reports.

The high energy input and the cost of several large heat pumps that would be necessary to compensate for the temperature difference are also problematic. While the operating costs for geothermal energy are 177 euros per megawatt hour, the use of regional biomass only costs 146 euros. In addition, deeper drilling, which could provide higher temperatures, is not permitted for water protection reasons. These considerations led to geothermal energy losing priority in the local council and biomass coming back into focus.

Biomass as a central energy source

There is already a biomass site in Neckarsulm that has been using wood chips to generate energy for over 20 years. Additional locations are currently being examined. However, there are also critical voices regarding the energy intensity of growing, transporting and processing biomass. This form of energy is considered climate-friendly, but not completely climate-neutral. The City of Neckarsulm has recognized that a clear plan is required for a complete transformation and replacement of fossil fuels with renewable energies.

Neckarsulm must achieve a climate-neutral heat supply by 2040, in accordance with the requirements of the new Climate Protection and Climate Adaptation Act of Baden-Württemberg. The local council has commissioned the administration to develop a heat transition strategy based on a municipal heat plan. Municipal utilities and regional utilities play a crucial role in this.

Renovation strategies and investments

The city has already planned six starter measures for the next five years. This includes, among other things, the renewal of the energy supply in the Viktorshöhe climate district and the transformation of the biomass cogeneration plant. Furthermore, the heating network on Binswanger Straße is to be expanded and a heat map is to be created to raise awareness for building renovations. The aim is to increase the renovation rate in existing buildings to 2 to 5 percent annually. These ambitious plans require investments of around 104 million euros, with the city relying on financial support from the federal and state governments.

In addition, the municipal utilities are examining alternative technologies such as photovoltaics and solar thermal energy. Funding for the planning of these technologies has already been applied for from the Federal Funding for Efficient Heat Networks (BEW). Even if geothermal energy has not yet been completely excluded from considerations, the goal remains to achieve a climate-neutral heat supply in Neckarsulm by 2045.