Our headquarters: The city of Mannheim is one of the most progressive municipalities in Germany when it comes to the municipal heating and energy transition. The city aims to be climate-neutral by 2035 at the latest – an ambitious goal that can only be achieved with integrated concepts, technological diversity and local responsibility. The focus here is on municipal heating planning, the expansion of renewable energies, decentralized solutions such as heat pumps and the consistent decarbonization of the district heating supply – in particular through the use of previously underestimated potential such as river heat. 

Challenge and reality: skilled workers, investment, acceptance

A key issue in Mannheim's heating transition is feasibility: expansion requires not only investment, but also skilled workers, planning resources and social acceptance. According to former MVV CEO Dr. Georg Müller, who left the company at the end of 2024, “not every political wish can be implemented in reality” – a sober but necessary assessment. Mannheim therefore relies on dialog, transparent communication and locally adapted solutions.

A survey published in March by the Fraunhofer Cluster of Excellence “Integrated Energy Systems” (CINES) comes to similar conclusions. One year after the introduction of the Heat Planning Act, the study shows how German municipalities and municipal utilities assess the implementation of this new mandatory task. In particular, the lack of qualified specialists and coordination between local stakeholders are seen as key challenges.

In addition, municipal heat planning in Germany is unevenly developed. While some municipalities such as Mannheim or Heidelberg have already drawn up detailed heating plans, others are still at the very beginning. Challenges often include limited human and financial resources as well as a lack of data on the current heat supply. 

Mannheim sees the heating transition as a core municipal task

The legal obligation to plan heating has set an important framework – but Mannheim has been going beyond this for years. According to Müller, the city is pursuing the goal of “radically decarbonizing the local heating supply”. In doing so, Mannheim is focusing on an integrated strategy that takes into account decentralized solutions such as heat pumps, photovoltaics and intelligent control technologies in addition to district and river heating.
 

The underestimated lever: river heat from the Rhine

The use of river heat from the Rhine also plays a key role in Mannheim. As described in the ZfK specialist article “River heat - the underestimated lever of the heating turnaround”, this heat source has immense potential in Mannheim. The Rhine heat can be fed into the district heating grid via large heat pumps – climate-neutral, base-load capable and seasonally independent. A project of this kind was already launched in Mannheim's industrial port in 2023.

The advantages are obvious:

• Renewable energy source, locally available
• Reduces dependence on fossil fuels
• Supplement to industrial waste heat and biomass
   

District heating as the backbone - but not the only solution

In an interview with ZfK, Müller makes it clear that district heating forms the backbone of decarbonization for Mannheim - but not across the board. “Not every region will be able to be supplied completely via district heating - not even in Mannheim”. Mannheim is therefore planning parallel decentralized solutions in districts that cannot be economically connected to the heating grid. This is also where PAUL Net Zero comes into play – as a scalable solution with heat pumps, photovoltaics and AI-controlled heating control for existing properties.

Decentralized intelligence: heat pumps, photovoltaics and AI complement district and river heating

Heat pumps significantly reduce primary energy consumption by using environmental heat efficiently and can be intelligently controlled. By integrating them into building automation systems, their operation can be adjusted according to demand, combined with photovoltaic systems and their own power consumption optimized. Modern heat pump systems are able to efficiently cover the heating requirements of even large apartment buildings. The combination of several heat pumps (cascade operation) can achieve heating outputs in the megawatt range and thus represent a fully-fledged alternative to existing gas heating systems. In addition, heat pumps can be easily integrated into district and local heating networks, further increasing their flexibility.

Photovoltaics enable the direct and efficient use of solar power to operate heat pumps. With the help of building automation and AI-supported control, self-consumption can be prioritized, loads can be shifted and energy use can be dynamically optimized. Smart algorithms automatically decide whether to store, feed into the grid or use the electricity directly - ensuring that renewable energy is used as efficiently as possible in the building. 

Artificial intelligence enables learning buildings by analyzing consumption patterns and automatically initiating energy-saving measures. Adaptive algorithms control heating systems precisely based on occupancy data, weather forecasts and user behavior, while continuous system monitoring detects failures at an early stage and reduces maintenance costs. By intelligently linking heat pumps, photovoltaics, storage systems and grid data, AI optimizes the entire energy infrastructure - for more flexibility, lower costs and greater environmental friendliness.

In Mannheim, for example, the PAUL Net Zero sector coupling could ideally complement district and river heating and immediately increase the energy efficiency class of existing properties in districts that cannot be connected to heating networks. The aim is to make the buildings immediately cost-efficient and economically CO₂-neutral – without costly renovations.
 

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Mannheim shows how the municipal heating transition can work

The city of Mannheim is leading the way as a role model - with a concrete roadmap, technological diversity and consistent target orientation. The use of river heat, the decarbonization of district heating and the use of smart, decentralized technologies such as heat pumps and AI make Mannheim a real-life laboratory for the heating transition.  

A model that other cities should take a close look at. Because time is pressing - and Mannheim is proving that the municipal heating transition is feasible.

Let's talk about PAUL Net Zero – get in touch now