Revolutionising Lemgo's Heat Transition: GEA's Innovative Wastewater Heat Generation

In a groundbreaking move towards climate neutrality by 2035, the city of Lemgo is harnessing the power of its wastewater with cutting-edge technology from GEA. With the installation of two advanced heat pumps, GEA is spearheading Lemgo's heat transition, leveraging the city's wastewater treatment plant, combined heat and power (CHP) facility, and the River Bega to generate sustainable heat. This transformative initiative is set to supply the historic city centre with approximately 18 million kilowatt hours of low-carbon heat annually, resulting in a remarkable reduction of 3,200 tons of COâ‚‚ emissions per year. Notably, the heat extracted from the wastewater treatment plant alone can fulfil two-thirds of the old town's heating needs or twelve percent of the entire district heating network's demand. Operating around the clock for up to 7,500 hours per year, these heat pumps maximise efficiency and benefits for the city.

Inspiration from GEA's Malmö Project: Tailored Solutions for Municipal Utilities
Stadtwerke Lemgo drew inspiration from GEA's successful heat pump project in Malmö, Sweden, where wastewater was effectively transformed into heat. During initial consultations in Lemgo, GEA proposed an innovative two-stage heat pump solution, replacing the initially planned configuration. Recognising its superior energy efficiency and economic viability, all stakeholders swiftly embraced this forward-thinking approach. Notably, GEA's proposition stood out as unmatched in the market, showcasing the company's leadership in tailored energy solutions.

Harnessing Wastewater for Sustainable District Heating
The utilisation of wastewater from Lemgo's municipal sewage treatment plant marks a pivotal aspect of the city's district heating strategy. The treated wastewater, with an average temperature of 13°C, presents a valuable heat source due to its abundance in the mixed water system. With over 1.5 MW of source power available for nearly 8,000 hours annually, coupled with existing infrastructure like the CHP plant and district heating connections, Lemgo maximises heat generation with minimal technical complexity. Notably, heat extraction occurs downstream of the treatment process, ensuring minimal disruption to wastewater treatment operations.

Overcoming Challenges: Collaboration and Innovation
Despite its promise, the project encountered challenges related to water quality, necessitating innovative solutions. Collaborative efforts between Stadtwerke Lemgo and GEA led to the implementation of an additional filtration system, ensuring sustained operation of the heat pump amidst evolving conditions. Furthermore, GEA's utilisation of natural refrigerant ammonia underscores its commitment to environmental protection, offering superior performance while aligning with global targets for reducing emissions.

Looking Ahead: Towards Carbon Neutrality
While achieving a significant milestone, Stadtwerke Lemgo remains committed to furthering its sustainability goals. Plans are underway to generate over 55 percent of district heating from renewable sources by 2028, with initiatives including a large-scale solar thermal system, expanded heat storage capabilities, and integration of wind and biomass energy. These ambitious endeavours underscore Lemgo's steadfast commitment to realising a carbon-neutral future.

In conclusion, GEA's transformative technology, coupled with Lemgo's visionary approach, sets a precedent for sustainable urban development, demonstrating the power of innovation in shaping a greener, more resilient future.