Stuttgart-Münster combined heat and power plant generates reliable and cost-effective energy for the mid-Neckar region. The site’s focus is on recycling waste. Alongside three hard coal-fired boilers that will continue to operate until spring 2026, two gas turbine plants and a waste incineration plant produce electricity and district heating in combined heat and power mode. The waste-to-energy plant is a key component of residual waste disposal in Baden-Württemberg. In addition, a large-scale heat pump generates district heating via its cooling water discharge. EnBW has set itself the goal of phasing out coal-fired power generation before the legally mandated phase-out, provided regulatory and economic conditions allow for it. As part of this strategy, the site has been converted to run on hydrogen in the future (known as a fuel switch): A new combined cycle gas turbine plant will initially be operated using natural gas to generate electricity and district heating and can be converted to run on hydrogen as a fuel at a later date.
We offer free guided tours of Stuttgart-Münster combined heat and power plant all year round – with expert information provided by our employees.
Fuel Switch
Project introduction
EnBW is consistently continuing the decarbonization of its generation portfolio with the expansion of renewable energies. Due to legal requirements, all coal power plants in Germany must also be shut down by no later than 2038, including the plant in Stuttgart-Münster. The most important consideration in the region, however, is guaranteeing security of supply for electricity and district heating, which is why EnBW has built a controllable, hydrogen-ready gas turbine plant at the site:
- The new, gas-fired plant can achieve a much higher fuel utilization rate than other types of power plants.
- In addition, current reports call for a reduction of CO₂ emissions and other pollutants – such as dust, sulfur dioxide (SO₂) and nitrogen oxides (NOₓ). The switch to natural gas will also eliminate heavy metals emissions from the previous coal combustion.
- As a result of this fuel switch to natural gas, the coal phaseout for the Stuttgart city area has already been completed many years ahead of the legally stipulated date.
As soon as hydrogen is available in sufficient quantities and the supply infrastructure has been converted accordingly, the power plant can operate on hydrogen, which would allow for an even greater reduction in CO₂ emissions from electricity and district heating generation compared to coal-fired power generation. A certain hydrogen blend ratio can be burned from the moment the plant is commissioned – complete combustion of hydrogen requires the gas turbine to be converted, which can be done at any time during one of the routine major overhauls. This means that the switch to hydrogen can be made at a later date with no major hurdles. Find out more about the fuel switch here.
Technology
The gas turbine plant is replacing the existing three coal boilers in the hard coal block:
- There is a so-called common steam range on the site. All on-site power plants feed the steam they generate into this large steam pipe.
- The high-pressure steam is then channeled along the common steam range to the steam turbines (two condensing and one back-pressure turbine), which produce electricity and district heating.
- The new gas turbine plant also feeds the steam it generates into the common steam range, which means that the existing infrastructure is used
The district heating produced in the course of electricity generation is fed into the “Mittlere Neckarschiene” district heating network, which is also connected to the Altbach/Deizisau combined heat and power plant and the Stuttgart-Gaisburg combined heat and power plant. It is used to supply many industrial companies, private households and public buildings in Altbach, Deizisau, Esslingen, Plochingen and Stuttgart.
Large-scale heat pump
In addition to the fuel switch, another step toward transforming the district heating supply in the Stuttgart region has already been taken at the site. Since April 2024, a large-scale heat pump has been using the waste heat from the cooling water discharge to generate up to 24 megawatts of district heating. The pump enables the large-scale use of waste heat for energy needs and is one of the first of its kind in Germany on this scale.
One challenge involved integrating the new heat pump into the power plant’s existing infrastructure while maintaining ongoing operations. The project was funded by the German Federal Ministry for Economic Affairs and Climate Action as part of the ideas competition “Reallabore der Energiewende” (or “Field labs for the energy transition”) and is part of the joint research project “Large-scale heat pumps in district heating networks”. The investment costs ran to around 17 million euros.
The heat pump technology, familiar from building heating applications, is used on a large scale in Stuttgart-Münster. By extracting the required environmental heat from the power plant’s cooling water, the large-scale heat pump consequently reduces the amount of heat discharged into the Neckar and uses the energy contained in the cooling water to generate district heating. It is powered by electricity generated from the waste incineration plant.
Approach
Project phases
This is where we inform you about important events and milestones relating to the planning and construction of a gas turbine plant on the Stuttgart-Münster site. You will find the latest information here on the timetable for the planning and approval process as well as the progress of the construction work.
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October 2025
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Start of commercial operation of the gas turbine plant (fuel switch)
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April 2025
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Start of commercial operation of the large-scale heat pump
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April 2025
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Official commissioning of the gas turbine plant (fuel switch)
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October 2024
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The gas turbine plant’s hot startup phase begins
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April 2024
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Official commissioning of the large-scale heat pump
Gas turbines delivered and moved into position |
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November 2023
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Commissioning work starts on the large-scale heat pump
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31 March 2023
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Groundbreaking ceremony for the new building housing the gas turbine plant and the large-scale heat pump
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October 2022
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Stuttgart Regional Council meeting to discuss the project
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22 March 2022
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Investment decision taken by EnBW’s Supervisory Board
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21 July 2021
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Project presented to Bad Cannstatt council committee
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23 April 2021
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Scoping-Meeting0In complex planning processes, a scoping meeting is held by the authority overseeing the process (in this case Stuttgart Regional Council). With the involvement of public agencies and specialist authorities, the meeting is used to formally determine the subject, scope and methodology of the regional impact and environmental impact studies as well as the content of the application documents that need to be drawn up.
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20 April 2021
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Project presented to Münster council committee
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13 April 2021
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Virtual information event for the public
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12 April 2021
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Information event for professional associations and citizens’ initiatives
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Project diary
October 2025: Commercial operation of the gas turbine plant begins
After a construction and commissioning period lasting just two and a half years, the new, hydrogen-ready gas power plant in Stuttgart-Münster finally commenced commercial operations. The plant was officially placed into operation in April of this year, and it is now ready to generate a reliable supply of electricity and district heating for the city of Stuttgart just in time for the heating season. Following registration with Stuttgart Regional Council, the power plant is now part of the district heating network for the mid-Neckar region. Together with the combined heat and power plants in Stuttgart-Gaisburg and Altbach/Deizisau, it will be able to supply around 28,500 households, 1,400 businesses and 380 public entities with district heating in the future. The power plant is now also approved for the so-called balancing market, which, as part of the overall electricity market, ensures that the electricity grid in Germany remains stable at all times.
Insights into how the hydrogen-ready gas turbine plant was built can be found here.
June 2025: Hot startup of the black start unit
The hot startup of the black start unit began at the end of June. This innovative system makes it possible to start the newly installed gas turbines in the event of a power failure. The black start unit consists of a black-start-capable inverter with a nominal output of five megavolt-amperes (10 MVA in total) and 18 battery units with a total capacity of 6.7 megawatt-hours (13.4 MWh in total). Commissioning work will continue over the coming weeks.
April 2025: Power plant open day
On 13 April 2025, we celebrated the official commissioning of the fuel switch power plant by holding a power plant open day together with the public. In addition to guided tours of the new H₂-ready gas power plant and the waste-to-energy plant, there was an extensive program of activities for children. The Bad Cannstatt musical society created a lively atmosphere in the marquee. We are delighted that the power plant open day went down very well with a total of around 2,700 visitors.
April 2025: Official commissioning of the fuel switch power plant
Following the official commissioning of one of Germany’s first H2-ready gas power plants on 11 April 2025, we have reached a milestone the ongoing transformation of our generation infrastructure. In total, the new power plant has an electrical output of 124 MW and a thermal output of 370 MW. Together with waste incineration, the entire site will be capable of generating 450 MW of heat in the future. Stuttgart has thus become one of the first major coal-free cities in Germany. We had the pleasure of celebrating this occasion together with our hosts, EnBW CEO Dr. Georg Stamatelopoulos (right) and our Board Member for Generation Peter Heydecker (left), as well as our guests (from left) CEO of Siemens Energy, Dr. Christian Bruch, Stuttgart’s Mayor Dr. Frank Nopper and State Secretary Dr. Andre Baumann.
Get an insight into events on the construction site leading up to the commissioning process here.
November 2024: The hot startup phase continues. The waste heat boilers are now being commissioned following the gas turbine test runs. These boilers use the hot flue gases from the gas turbines to generate steam, which in turn produces both electricity and district heating. As part of the commissioning process, the steam pipes were blown down on several days between the end of October and the end of November. This involves steam being discharged from a separate pipe, which generates noise. Silencers were installed to minimize any such noise. The process is necessary in order to be able to safely commission the plant in 2025.
October 2024: The “hot startup” phase in Stuttgart-Münster begins. The construction process that started back in January 2023 reached the so-called “hot startup” phase for the first gas turbine this week. The former coal boiler and heating oil-driven turbines have been replaced by a highly efficient gas turbine system with an output of 124 megawatts. To check whether everything is working as intended, tests will now be carried out repeatedly over several days. This includes gradually increasing the output of the gas turbines to adjust and test them for optimum operation. It will be possible to see the flue gases generated during the combustion process as they are discharged from the newly constructed chimney, just like the flue gases from the chimney for the existing waste and coal boiler.
September 2024: An ABC of the pipelines. Different brightly colored pipelines can be seen running along the pipe bridges and through the highly efficient gas turbine plant. Installing these pipelines on the construction site takes a lot of time. But what is being transported by which pipeline?
Green:
- A cooling water pipeline providing water to cool the gas compressors with a total length of approx. 340 meters
Yellow:
- A high pressure natural gas pipeline running from the gas control pressure measurement station to the gas turbines via the compressors with a total length of approx. 290 meters
- A low pressure natural gas pipeline running to the hot water boilers, waste heat boiler and existing plant with a total length of approx. 450 meters
Grey/brown:
- A district heating pipeline in the M1 grid supplying downtown Stuttgart with a total length of approx. 130 meters
- A district heating pipeline in the M2 grid supplying North/West Stuttgart with a total length of approx. 1,300 meters
August 2024: Delivery and installation of the transformers. In August 2024, four transformers, two auxiliary power transformers and two generator transformers were delivered on heavy goods vehicles and installed. The generator transformers each weigh 106 metric tons and convert the generator voltage into the voltage used in the high-voltage public grid. This means that the electricity can be fed directly into the public grid. The auxiliary power transformer are lighter and each weigh 27 metric tons. They convert the generator voltage into the medium-voltage electricity required by the power plant itself to efficiently cover the plant’s electricity needs (such as for pumps, control systems and lighting) from own generation.
More insights can be found here.
June 2024: East pipe bridge lifted into position. The four sections of the east pipe bridge were lifted into place in June. The bridge connects the existing power plant with the gas turbine plant that is currently under construction. The pipe bridge is approx. 43 meters long and weighs a total of 110 metric tons. It carries, among other things, the pipes for ammonia water, fresh steam, heating oil and demineralized water.
May 2024: Delivery and lifting of the waste heat boiler chimney elements. At the end of May, the chimney elements for the waste heat boiler were delivered on heavy goods vehicles and lifted into place with a crane that can lift up to 500 tonnes. The two chimneys each consist of 2 segments and are 5.2 meters in diameter, 15 meters tall and weigh around 30 tonnes. They will be used to discharge the combustion gases generated during operation of the gas turbine plant. They also contain an emission measurement system for each of the two gas turbines, so that compliance with the permissible emission limits can be monitored at all times.
You can find more insights here.
April 2024: Official commissioning of the large-scale heat pump. On 8 April 2024, the large-scale heat pump at the Stuttgart-Münster waste-to-energy combined heat and power plant was officially commissioned by EnBW CEO Georg Stamatelopoulos, Minister for the Environment, Climate Protection and Energy Sector of Baden-Württemberg, Thekla Walker, and the Mayor for Urban Development, Housing and the Environment, Peter Pätzold. This large-scale heat pump with an output of up to 24 MW is one of the most powerful systems in Germany. It can supply about 10,000 households with district heating.
April 2024: Delivery and assembly of the gas turbines. In April, the two SGT-800 gas turbines were delivered to the construction site and installed. A gas turbine is a heat engine that converts thermal energy into rotational energy. An electrical generator uses this rotational energy to generate electricity. Exhaust gases leave the gas turbine at a very high temperature and can be reused to generate heat, steam and even more electricity. The two gas turbines have a total electrical output of 124 MWel.
February 2024: Start of construction of the black- start battery system. A black-start battery system is being built at the Stuttgart-Münster site. Construction work began in February 2024. The power required to start up the power plant at the site can be covered by the black-start battery system in combination with the gas turbines. The CO₂-neutral black-start battery system is also able to provide primary and secondary control power at short notice and thus help to stabilize the grid.
January 2024: Delivery and installation of the hot water boilers and associated chimneys. The three hot water boilers were delivered and installed in January 2024. Immediately afterwards, the three approx. 60-meter-high chimneys were lifted into place in 3 segments each. You can find more insights here.
December 2023: Commissioning of the large-scale heat pump. Commissioning of the large-scale heat pump began in December 2023. The large-scale heat pump will utilize the waste heat from the cooling water discharged at the site to generate up to 24 MW of district heating. The heat pump can not only make an contribution to the decarbonization of EnBW's district heating generation, but also serve as a building block for the city of Stuttgart in achieving its climate protection goals. You can find more insights here.
November 2023: Lifting of the northern pipe bridge. On 03.11.2023, the northern pipe bridge over Neckartalstraße was lifted into place in cooperation with SSB and the city of Stuttgart using a tandem lift with 2 cranes. The pipe bridge was installed on site before being lifted into place, including the district heating and natural gas pipes for supplying the city of Stuttgart. The natural gas pipelines are already 100% H2-ready.
October 2023: Delivery and assembly of the first waste heat boiler for the gas turbines.The components of the first waste heat boiler were delivered by heavy goods vehicle at the end of September. The individual components that ultimately make up the waste heat boiler are welded together piece by piece and assembled. The waste heat boiler utilises the heat recovered from the gas turbine to generate steam and hot water to drive the steam turbine. When fed into the respective grids, district heating and electricity are generated.
September 2023: Delivery and installation of the large heat pump.The components of the large heat pump were delivered and installed at the beginning of August 2023. Components such as the evaporator, intercooler and condenser were delivered and installed in various partial deliveries. The large heat pump can generate up to 24 MW of district heating.
August 2023: Steelwork for the gas turbine building. Work on the steel structure for the gas turbine building began in mid-July 2023. The two gas turbines, each with a capacity of 24 MW, will be housed in the gas turbine building along with the waste heat boilers and two chimneys. The gas turbine building will be constructed as a steel skeleton frame using approx. 1,300 metric tons of steel girders and its dimensions will be approx. 65.20 x 45.15 x 34.00/17.80 meters (L x W x H). The main structure of the steel skeleton frame generally consists of a series of steel columns and horizontal beams connected by means of riveting, bolting or welding. This construction method enables rapid progress to be made, with completion already scheduled for mid-May 2024.
July 2023: Construction of the stair tower. In July 2023, construction began on the approx. 32.4-metre-high stair tower, which adjoins the district heating building to the south by means of bridges and the hot water boiler plant to the north. The special feature is that the stair tower was concreted using slipforming. Slipforms are used when jointless structures or short construction times with high daily output are required. The stair tower was erected within 6 days in 24-hour shift operation.
June 2023: Chimney foundations with integrated crane support. In keeping with the motto 2 in 1, the chimney foundations were used as a crane support. The crane was erected using a built-in part that serves as a rear anchor to stabilize the crane. The 60-meter-high crane has a working radius of up to around 60 meters and can thus cover almost the entire construction site. In 2024, the chimney will then be built using the slip form method. This approach guarantees a flexible, efficient and economical construction process.
May 2023: Concrete casting and reinforcement of the gas turbine building. Once the foundation work was completed, the reinforcement work started, along with the concrete casting in stages for the two gas turbine foundations. Approximately 600 m³ of concrete were needed for each of the foundations, which is the equivalent to around 3,000 bathtubs per foundation. It took 130 concrete mixers and two concrete pumps to complete the job. The concrete structural elements are reinforced using steel, increasing the load-bearing capacity of the building being constructed on them. The 124 MW gas turbines are housed in the gas turbine building.
April 2023: Installation of the driven piles. Work on installing the 202 driven piles began in April. Pile foundations are deep foundations where the loads of supporting structures are transferred to deeper soil layers with a higher load-bearing capacity. Soil layers with poor load-bearing capacity are thus bridged using piles. With so-called pile foundations, the piles are driven into the ground with a pile driver until a soil layer sufficiently capable of bearing the load has been reached. Concrete is then poured into them.
March 2023: Groundbreaking ceremony and official opening of the building site. The starting signal was given in Stuttgart-Münster for the construction of the new gas turbine plant and large-scale heat pump. Minister for the Environment, Climate Protection and Energy Sector for Baden-Württemberg Thekla Walker, Mayor Dr. Frank Nopper and the EnBW Board Member responsible for sustainable generation infrastructure Dr. Georg Stamatelopoulos performed the traditional groundbreaking ceremony on 31 March 2023.
February 2023: Start of foundation works. Foundation works create a stable and load-bearing basis for the buildings and machinery associated with the new plants. This covers groundwork such as the excavation of pits and the construction of the foundations, including pile foundations.
January 2023: Start of construction works at Stuttgart-Münster. The construction project got under way in Stuttgart-Münster on 9 January 2023 and work has been continuing ever since. The start of construction also sees the introduction of a temporary alternative traffic management concept:
- A contraflow system for traffic traveling out of town at the intersection of Neckartalstraße/Voltastraße
- Normal flow of traffic resumes at the intersection of Neckartal-/Haldenstraße
- City-bound traffic uses the remaining lane with suspension of the cycle lane on Neckartalstraße
This traffic concept means that no major diversion is needed for car traffic. Cyclists are diverted via the Neckartal cycle path. This allows the routes at the Voltastraße intersection to remain open.
Frequently asked questions
Here you can see at a glance the advantages which the gas turbine plant could offer over the hard coal block that has been used until now:
- Compared to hard coal, natural gas produces lower direct CO₂ emissions during electricity generation. According to current plans, CO₂ emissions from the gas turbines could be about 60% lower. The plant is designed to replace the existing generation capacity of the coal-fired units.
- According to forecasts, a reduction in air pollutant emissions is expected: Nitrogen oxide emissions (NOₓ) could drop by about 45%, while emissions of sulfur oxides (SOₓ) and particulate matter would be significantly lower. Heavy metal emissions will cease with the end of coal combustion.
- With the decommissioning of the coal-fired units, the existing coal storage facility will be eliminated, thereby eliminating associated dust and noise emissions.
- Traffic volume may decrease, as coal deliveries and a large portion of the transport of additives and residues from flue gas cleaning will no longer be necessary in the future.
- Noise from the plant is to be limited through noise reduction technology. In addition, coal-fired boilers, auxiliary steam generators, and flue gas cleaning systems will be decommissioned.
- According to current plans, the warming of the Neckar River may decrease, particularly during the summer months. Recooling systems are planned to minimize the additional cooling water requirements.
- The new plant is intended to maintain the district heating supply. According to current plans, more efficient plant technology will replace parts of the existing infrastructure for the Stuttgart-Northwest and Cannstatt district heating networks.
In the field of heat generation in particular, renewable energies are currently not in a position to fully replace fossil fuel within a matter of years.
Natural gas represents an intermediate step in this regard, not least because it can lead to a further reduction in greenhouse gas emissions in the short term compared to coal. It is important to remember that natural gas is only intended to be used for a transitional period.
The gas turbines are flexible and can later be converted to burn other gases such as green hydrogen. Green hydrogen is produced by means of electrolysis using electricity from renewable energy sources.
As soon as the combined cycle gas turbine (CCGT) plant is commissioned, it will be possible to add up to 20% hydrogen to the natural gas, which can further reduce greenhouse gas emissions. The switch to natural gas thus represents a bridging option culminating in an energy supply with hydrogen.
As part of the permitting process, expert reports are prepared that also assess potential impacts on nearby residents. These include, among other things, a noise assessment and a forecast of air pollutant emissions. These evaluate the impact of the new facility on the surrounding area:
- Noise control: Once the new plant is operational, the plan is to decommission the old facilities, such as the coal-fired boilers, coal storage, and flue gas cleaning systems. These have been among the primary sources of noise at the site to date. The new plant will be equipped with state-of-the-art noise reduction systems (e.g., silencers, sound barriers) to comply with legal limits (TA Lärm). In addition, transportation associated with flue gas cleaning will no longer be necessary, which can reduce traffic volume and the associated noise.
- Water pollution control: The new power plant facilities will not require additional cooling water to be drawn from the Neckar river. Cooling will be provided by recooling systems on the building roof using a closed water-glycol system. This is expected to reduce heat discharge into the Neckar river. Particularly during periods of high summer temperatures, the plan is to significantly reduce heat discharge compared to current levels. In addition, low-noise recooling systems are planned.
- Immission Control: According to current projections, emissions can be significantly reduced compared to previous operations: nitrogen oxides (NOₓ) by over 45 % and particulate matter by about 88 %. Emissions of heavy metals will be eliminated with the phase-out of coal-fired generation. These reductions are based on the more efficient combustion technology of gas turbines and the planned use of SCR technology (catalysts in the exhaust gas path), which are designed to reliably comply with legal limits.