Success of the Holzkirchen combined geothermal heat and power project
The combined geothermal heat and power plant of Holzkirchen in Bavaria/ Germany has been a great success for the municipality, while further expansion could be an option but then in cooperation with other communities in the region.
The geothermal project of Holzkirchen in Bavaria/ Germany has had its up and downs, but things are looking like there is a “happy ending”, as reported by local publication Merkur. The Holzkirchen geothermal projects provides district heating and electricity to the local community and with the success the city’s mayor can imagine expansion and then possibly as a joint project of several communities.
So while the investment of EUR 19.175 million ($21.1 million) in tax money was promising, it was not a risk-free project and took 7 years until it started operations. But the investment has paid off
In July 2019, the plant fed electricity into the grid for the first time and now the refinancing of the plant has started. With secure revenues, a good basis has been created, so the mayor. Beyond the direct investment of EUR 19.2m into the municipality-owned Geothermie Holzkirchen GmbH, the city also granted a subsidiary loan of EUR 5.825 million ($6.4 million), with the rest of the investment coming from a syndicated bank loan.
With the feed-in-tariff guaranteed for 20 years and the corresponding calculation, the plant would be paid off within that period and the municipality can then operate a plant that works and has been paid off. Naturally, the thermal energy provided through the growing district heating network, provides direct sales and income as well.
Today, around one-fifth of the municipality is connected to the district heating network, including many large buildings and with the availability of geothermal heat, demand has actually increased and the local utility is now to gradually add new connections. This is organisational not easy, as laying pipes disrupts traffic.
The power plant cools with air coolers, as the initially planned water cooling was not practical due to the closeness to a nearby highway.
The 3.4 MWe power plant was built by Italian Turboden. Details can be found on the company’s website, here.
Now there are considerations for an additional well to tap geothermal energy at a depth of more than 5,000 m. With the example of the plant and operation, it shows that the courage in developing the plant has paid off. Any addition would have to be as efficient in regards to economics. With the little footprint and visibility, geothermal has been a more attractive option than wind mills. For a new project though, it would be advisable to cooperate with other communities in the region, so the mayor.