From pv magazine Germany
Hanover-based utility Enercity AG has begun construction on a major heat pump project as it moves away from coal-based district heating. The company, which currently still relies heavily on the Stöcken coal-fired power plant for heat supply, has already shut down the first of its generating units, with the second scheduled to follow in spring 2028.
The retired capacity will be replaced by a mix of biomass and power-to-heat plants, expanded heat recovery from a waste incineration facility, and a series of large-scale heat pumps. The latest addition is a 30 MW heat pump being built at Hanover’s central wastewater treatment plant in the Herrenhausen district.
The system is intended to supply district heating to around 13,000 households at a flow temperature of 95 C. To integrate the plant into the existing heating network, the Leine River will be crossed using horizontal directional drilling.
The heat source is treated wastewater, which maintains stable temperatures of 12 C to 16 C even in winter. Motors, compressors, two central heat exchanger packages, and other key components are supplied by Swiss manufacturer Friotherm.
“Within just a few days, the assembly team installed the individual components, each weighing up to 50 tonnes, in front of the building and moved them into place with millimetre precision on rails,” said Michael Hartung, managing director of Enercity Contracting GmbH, which is responsible for the project. “In the coming weeks, we will connect the components via several hundred metres of piping for the evaporator, condenser, and clean water circuits.”
The heat pump is expected to generate around 130 GWh of district heating annually, covering around 7% to 8% of Hanover’s demand. Enercity is investing approximately €56 million ($65.7 million) in the project, which is supported by €22.5 million in federal funding from the Federal Funding for Efficient District Heating Networks (BEW) programme.
Enercity plans to expand Hanover’s district heating network from 360 km to around 550 km. By 2040, the company aims to supply approximately 18,000 buildings with climate-neutral district heating—around four times the current level.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.