A new development area in the town of Bad Nauheim, Hesse, will have its heat and power supplied by an innovative cold local heating system which will be Germany's largest ground collector for geothermal energy.

The joint ‘KNW-Opt’ research project was begun in May 2020 and brings together the local public utilities company Stadtwerke Bad Nauheim (responsible for construction and operations) with the Technical University of Nuremberg (TUN), the Friedrich-Alexander University of Erlangen-Nuremberg, the Technical University of Dresden and the energy companies Enisyst GmbH and Consolinno GmbH. The partners have invested EUR 6 million collectively.

"The neighbourhood in Bad Nauheim-South is a beacon project for the innovative supply of heat and cold through near-surface geothermal energy. To my knowledge, it is also the largest of its kind in Europe," says professor Volker Stockinger from TUN in an article in the journal Wetterauer Zeitung.

At the centre of the novel energy system are the network heat pumps and expansion vessels that keep the water-glycol mixture in the pipes moving along. The heat is pumped into the households above the subterranean network. During the four year research period, data from sub-soil sensors, groundwater measuring points and temperature sensors in the brine will converge in a smart energy centre and then sent to a cloud for analysis.

Meanwhile, on the surface, the residents will enjoy reliable energy supply that is both 100 percent eco-friendly and cost-effective. “We save the environment up to 750 tonnes of CO2 per year – this corresponds to about one third of the amount that the Bad Nauheim municipal forest binds in the same period of time”, says Peter Drausnigg, MD of the utilities company.