Large scale heat pump powers cleaner heat for Stuttgart

Stuttgart’s district heating network is expanding, driven by demand for reliable heat with a significantly lower carbon footprint. At the same time, legacy infrastructure at the Stuttgart-Münster site required modernization as EnBW advances its coal phase-out strategy and transitions toward more sustainable heat sources. The challenge was to integrate a high-capacity heat pump into a complex, continuously operating site while delivering meaningful emissions reduction.

EnBW implemented a large water-to-water heat pump that captures heat from the plant’s cooling-water discharge. The system uses a four-stage turbo compressor with intercooling and is integrated directly into the district heating network.

Johnson Controls provided focused engineering and integration support, helping align the new heat-pump system with existing plant processes and control architecture so it could operate reliably within the continuously cunning CHP environment. The installation was completed while the site remained fully operational, ensuring uninterrupted electricity and heat generation.

The 24MW large-scale heat pump now feeds low carbon heat directly into Stuttgart’s district heating network, supplying roughly 10,000 households with climate-neutral heat and reducing annual emissions by an estimated 15,000 tons of CO2. The system also raises the share of climate-neutral heat in the regional network by about 10 percentage points and lowers thermal discharge into the Neckar by capturing waste heat that previously went unused.

Since commission, the installation has become one of Germany’s largest operational heat pumps, demonstrating that substantial district heating output can be delivered from existing waste heat streams. The project strengthens regional energy resilience and supports EnBW’s long-term decarbonization roadmap, including future readiness for hydrogen-capable gas turbines. Stuttgart-Münster now serves as a replicable model as cities across Germany accelerate their heating transition strategies.

EnBW Stuttgart is one of Germany’s largest energy suppliers, operating electricity, district heating and infrastructure networks across Baden-Württemberg and beyond. The company is pursuing an accelerated coal phase-out and investing in technologies that deliver low carbon, efficient and reliable heat at scale.