Anthropocene logbook entry 2008-2023: “Ismaning|BY - Where urban building heat comes from the earth"

According to the IHK | Munich currently only covers 0.5% of the heat demand in the geothermal energy flagship state of Bavaria (BY). The magazine's cover story about geothermal energy and its potential for Germany, asks: “Why so little?”, and how the technical development and applications throughout the country is accelerating.

When the local council of Ismaning was faced with the decision in 2008: “Shall we do it, or not?”, the decision was fortunately: “Of course – Let’s do it!” At the crossroads between “Continue as always!...” (using fossil fuels as exclusive resource for urban|industrial building heating energy) vs. “Invest 100 million Euros in the future, without knowing exactly whether it will work that way...” – pretty brave! Especially 15 years ago.

Fig.1: The community of Ismaning at a crossroads in 2008: Top left (somewhat allegorically represented in the form of the Seebach with its divided waterway at the local mill), whether a large-scale geothermal energy site should be set up or not. The decision to take on such a technical and financial challenge is now paying off and catapults Ismaning and other communities in the region that have also decided on geothermal energy into a certain pioneering role for the entire German society.

The geothermal energy doublet at the Ismaning site (Fig. 1|top middle) has a drilling depth of 8,000+ ft, and was put into operation in 2011. It produces a fraction of the urban building heating energy at a water temperature around 175° F (Fig.1|top right). This heat is transferred via heating exchange pumps (Fig.1 photo series|middle panel) through special pipes (Fig.1|middle bottom) to the connected households. In the context of other energy forms and their utilization, such as e-mobility (partly generated via hydropower) plus wind|solar power, Ismaning is evolving and slowly migrating away from fossil fuels (oil|gas) in order to cover the local heat and energy needs in other ways.

The technical requirements for such a geothermal system to run for 50+ years are enormous. As Mr. Hobmeier, managing director of the operating company, explains that the capacities with a nominal output of 8 MW are currently at the limit and should be increased further in the near future due to local demand. Unfortunately, according to him, the energy output cannot be combined with the capacity of other plants in the region because each of these plants is fed with a site-specific water supply.

The characteristic water composition and temperature at each respective location inhibit such energy pooling. In addition to the ongoing operational requirements, such as the desalination of base water (Fig.2|right center) to generate the heating energy through heat exchange, it is legally required to always have critical (and expensive) components in stock to ensure immediate replacement (Fig .2|bottom right) without being hindered by supply chain problems.

Fig.2: The geothermal energy plant at the Ismaning site in the context of the surrounding agricultural areas, the transport infrastructure, and a growing number of renewable energy sources and the use of them (e-mobility through hydro | solar | wind power).

The community's 18,500 residents are increasingly enthusiastic users of geothermal energy. All data and facts about the Ismaning geothermal energy site can be found on the corresponding website of the Ismaning heat energy provider. Chapeau Ismaning!

For our young company with the vision and aim to support and promote “sustainability” as much as possible through technically innovative measures, Ismaning turned out to be the perfect choice as a “commercial site location”.

Carpe Diem | Best-of-Luck to Ismaning!