From coal to natural gas to hydrogen
Coal phaseout at the site in Altbach/Deizisau
By constructing a new combined cycle gas turbine (CCGT) plant, EnBW wants to replace coal with more climate-friendly natural gas at its Altbach/Deizisau site by means of a so-called fuel switch. This switch to natural gas represents the bridge that will ultimately lead to green gases such as hydrogen produced from renewable sources. EnBW thus plans to keep its promise of achieving climate neutrality by 2035 – the company’s contribution to climate change mitigation to which it has committed itself in line with the 2015 Paris Agreement. With this aim in mind, EnBW will continue to systematically expand renewable energy capacity and completely phase out the use of coal as an energy source in the medium term. In doing so, the number-one priority is to ensure that the supply of electricity and heat is never under threat.
Building diary
This is where we inform you about important events and milestones relating to the planning and construction of a combined cycle gas turbine (CCGT) plant on the Altbach/Deizisau site. You will find the latest information here on the timetable for the planning and permit process as well as the progress of the construction work.
January 2025: Heat recovery steam generator fitted
The building works in Altbach/Deizisau are progressing. The heat recovery steam generator for the gas and steam turbine power station was fitted in January. This heat exchanger uses the heat from the gas turbine’s flue gases to generate hot steam, which in turn drives a downstream steam turbine to generate further power. (Photographer: Markus Völter)
November 2024: Hot water boilers moved into position
In November, two of the three planned hot water boilers were already moved into position in the building constructed for the district heating system. The boilers are the main component of the hot water boiler system that is being constructed as part of the fuel switch project to guarantee the supply of district heating. Each boiler holds 65,000 liters of water and together they have a total heating output of 120 megawatts.
October 2024: Construction site open day
On 25 October 2024, EnBW opened the doors of its power plant site in Altbach/Deizisau to the public: Visitors were able to attend the inauguration ceremony for the new exhibition in the information center and participate in live tours of the fuel switch construction site. Lots of interested people had the chance to learn all about the preparations for the construction work for the fuel switch project during a one-hour tour of the power plant grounds. An H2-ready combined cycle gas turbine power plant is currently being constructed at the site. It will provide EnBW with the flexibility and controllable output necessary to secure the energy supply on a daily basis and support the expansion of renewable energies.
September 2024: Ongoing shell construction work
The shell construction work involves the foundations, base plates and concrete buildings. Work on the shell construction already began in early 2024 and significant progress can now be seen. The first foundations are ready for the next construction phase, namely the construction of the steel structures for the hall and also for the waste heat boiler and chimney.
August 2024: Gas turbine hub
The heart of the power plant was delivered in August: the 400 MW gas turbine. It was initially delivered to Belfort in France and then transported by ship to our jetty in Altbach/Deizisau. After being unloading from the ship, it is now being temporarily stored on site before it is moved into its final position in the power plant building.
July 2024: Installation of a rental boiler system
A rental boiler system will be installed and operated at the power plant site on a temporary basis to secure the supply of district heating to the “Mittlere Neckar Line”. The first pipework for the boiler was started in July 2024 and the system will be ready for operation from October 2024 onwards. It is anticipated that the system will be needed for a maximum of 6 months up until March 2025. Its operating hours are expected to be very low as it will only be used as additional backup for the district heating supply. The rental boiler system consists of 4 shell boilers and 2 heating oil storage tanks. It has a heating capacity of around 40 megawatts (MW).
May 2024: Construction of the chimney
A natural gas-fired hot water boiler system is being built to help secure the district heating supply together with combined heat and power plant 3. It consists of three shell boilers with a rated thermal input of up to 45 MW each so that the hot water boiler system has a total rated thermal input of 135 MW. The boiler system is being installed in the existing district heating building and will be connected to the existing infrastructure. A new 110-meter-high chimney with three flues is now being constructed for the hot water boiler system. It was delivered in six sections and installed in May.
April 2024: Start of excavation of the building pit
A total of 28,000 m³ of soil is being removed from the site every day by diggers and HGVs during the excavation of the construction pit. Despite the confined space, heavy floor slabs for e.g. the boiler house and gas compressor building are being constructed at the site without any disruption to ongoing operations. Work on the concrete structure is scheduled to be completed by the middle of 2024.
March 2024: Start of structural work (construction of the foundations)
The anchor cage for the chimney of the hot water boiler system is being installed. The sections of the 110-meter-high steel chimney will later be attached to the anchor cage. The flue gases from the three hot water boilers will be discharged via three chimney stacks. The hot water boiler systems will be used to provide district heating when, for example, the combined heat and power plant is not running or during times of peak demand.
January 2024: Constructing the bored pile foundations
Work to construct the around 1,200 bored pile foundations began in January. 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.
November 2023: Ground-breaking ceremony and official opening of the construction site
The symbolic ground-breaking ceremony was held at the traditional EnBW power plant in Altbach/Deizisau on 6 November 2023. Thomas Matrohs, Mayor of Deizisau, Thekla Walker, Minister for the Environment, Climate and Energy of the State of Baden-Württemberg, Dr. Georg Nikolaus Stamatelopoulos, Member of the EnBW Board of Management, and Martin Funk, Mayor of Altbach (from left), heralded the start of construction work on the fuel switch project.
October 2023: Pre-construction measures
The construction site becomes visible: careful planning and implementation of the pre-construction measures is crucial for a smooth and efficient conversion project. This includes setting up areas on the construction site for temporary facilities such as construction offices and carrying out dismantling work to create space for the conversion project and for storage areas. This stage of the project also includes dismantling facilities and buildings that are no longer required, such as the foundations of coal storage facility 3.
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Events
- Starting mid-July: Shell construction work and ramp-up of further construction activities. In this context, there will also be work that has to be carried out without interruption, e.g. concreting work. This means that construction work in the evening and at night as well as on Sundays is unfortunately unavoidable. We ask for your understanding in case of disturbances due to noise.