Drilling is underway again in the south of Munich

27.05.2025

Source: E & M powernews

The Laufzorn II geothermal project south of Munich is due to be completed by winter 2027/28. It is intended to contribute to a completely CO2-free heat supply for Grünwald.

The geothermal energy company Erdwärme Grünwald is starting drilling work for the Laufzorn II geothermal project. It is located south of the Bavarian capital of Munich. The drilling site is designed for six boreholes, each of which will reach depths of 3,600 to 4,000 meters. Experts assume that they will encounter deep water with a temperature of around 130 degrees Celsius. Around 200 liters of water per second are to be extracted and used to generate energy.

The municipality of Grünwald and the company Erdwärme Grünwald celebrated the start of drilling work with 150 guests at the "chisel consecration" on May 24. Grünwald's First Mayor Jan Neusiedl emphasized the importance of this ceremony: "The drill bit that we are dedicating today and the large construction site that we are experiencing here will contribute to our municipality being able to obtain its heat supply entirely from sustainable, CO2-free geothermal energy in the future." The chisel was blessed by the Catholic priest Albert Zott and the Protestant priest Christian Stalter.

Investment sum of 150 million euros

The drilling will be carried out in sections using different drill bits that are adapted to the respective rock. So-called roller bits are mainly used, in which toothed bevel gears cut the rock as they turn. Depending on the geological conditions, PDC bits (polycrystalline diamond cutters) or diamond bits can also be used.

Erdwärme Grünwald GmbH is thus expanding the existing Laufzorn geothermal plant. The plant, which has been in operation at the site since 2013, will no longer be able to meet long-term demand on its own, the company announced last year (we reported). The municipality is therefore investing in the second deep borehole that has now been started. Erdwärme Grünwald estimates the investment sum for the expansion at a further 150 million euros. Of this, 61 million euros are to be funded via the funding program for efficient heating networks (BEW).

The Laufzorn II geothermal project is scheduled for completion by winter 2027/28. Once the last well has been drilled and the drilling rig dismantled, construction of the heating plant is expected to begin in 2026, Erdwärme Grünwald added.

The expansion is necessary due to increasing demand, according to the geothermal company. The plan was to connect 100 households in 2022, but 423 new contracts were actually concluded. According to the company's own figures, a further 170 new households were connected in 2023. Last year, around 150 new connections were built. This means that around 3,770 residential and commercial units in Grünwald are now connected to district heating via geothermal energy - from single-family homes to municipal properties such as schools, kindergartens and the leisure park to major customers such as Bavaria Film, KGAL and the Schlosspassage.

Existing plant has been running since 2013

The existing Laufzorn I geothermal power plant with 40 MW is heat-led and went into operation in 2013. The ORC (Organic Rankine Cycle) plant produces electricity on a downstream basis in order to make optimum use of the source. To date, the energy plants comprise a production well and an injection well, each around 4,000 meters long, the deep pump at a depth of around 780 meters, with reserve and peak load oil boilers. A power-to-heat plant has been taking surplus electricity from the grid since the end of 2017, thereby contributing to its stability. The control room in Laufzorn also monitors the geothermal heating plant in the neighboring municipality of Unterhaching to the east.

Since 2013, there has been a 5-kilometre-long district heating pipeline between the power plant in Laufzorn and the geothermal heating plant in Unterhaching. In 2018, Erdwärme Grünwald finally took over 95% of the neighboring Geothermie Unterhaching Produktionsgesellschaft. At the same time, it was decided to shut down the Kalina power plant in Unterhaching for good.

Author: Heidi Roider