The Heilbronn CHP plant is a combined heat and power station owned and operated by Energie Baden-Württemberg(EnBW), a publicly listed energy company based in Germany.
The Heilbronn plant is one of EnBW’s major hard coal power stations, with an electrical output of 1.1GW and a thermal output of 320MW.
EnBW is converting the coal-fired plant into a Combined Cycle Gas Turbine (CCGT) power plant. The upgraded facility will have a maximum electrical and thermal output of 750MW and 190MW respectively.
The total cost of the project is estimated to exceed €500m ($547m), while the new CCGT plant is scheduled to commence operations towards the end of 2026.
The Heilbronn plant is situated near Stuttgart, the largest city and capital of the state of Baden-Württemberg, Germany. Positioned by the Neckar River on the city’s outskirts, the power station is within an industrial and commercial park.
Heilbronn coal-fired power plant details
The Heilbronn coal-fired power plant comprises a total of seven blocks, of which three are currently operational. Block 7, the plant’s largest hard coal block, is set to be replaced by the new CCGT facility. Blocks 5 and 6 are older units that serve as the grid reserve and are only utilised in the event of bottlenecks in the high-voltage grid.
With the commercial launch of the new CCGT plant, Block 7 will be progressively decommissioned. A similar approach will be followed for the reserve blocks 5 and 6. The new facility will also utilise Block 7’s existing cooling tower, water building and water intake and outflow infrastructure, ensuring a sustainable use of the existing infrastructure’s service life.
The district heating network will also be upgraded as part of the new construction, enhancing efficiency by transitioning from steam to hot water as the primary energy carrier.
Heilbronn CCGT plant details
The combined-cycle gas power plant will have a GE 9HA.01 gas turbine, an STF-D650 steam turbine, a W88 generator and a heat recovery steam generator with triple pressure and reheat capabilities. It will also feature GE Vernova’s fully integrated Mark*VIe Distributed Control System software.
EnBW also plans to construct a new 600MWh heat storage facility and a hot water boiler system with a thermal output of 160MW. The natural gas required for the plant will be supplied through the South German natural gas pipeline, which is currently under construction.
GE’s 9HA gas turbine has more than 64% combined-cycle efficiency. When combined with natural gas, the turbine can burn 50% of hydrogen by volume, delivering a net output of 680MW in combined-cycle mode.
The STF-D650 reheat steam turbine has an efficiency rating of 48%. The turbine incorporates high-performance gland and inter-stage sealing technologies, improved rear stages and GE’s latest 3D reaction blading.
Benefits of Heilbronn CCGT plant
The new plant will supplant the existing coal-fired power station with a more efficient gas-fired alternative, facilitating the combustion of 100% hydrogen in the future fuel mix by the 2030s.
The CCGT plant will significantly reduce airborne pollutant emissions, achieving 80% less NOx, 44% less total dust and 93% less SOx while eliminating heavy metal emissions.
Upon commissioning, the coal boilers, associated flue gas cleaning systems and coal-fired auxiliary steam generators will be dismantled, thereby mitigating the previously louder noise sources with modern noise control systems.
BERNARD Gruppe, an engineering company, was engaged to provide a traffic management concept, analyse the necessary traffic light modifications and estimate the costs for converting steam into hot water for the plant.
In June 2022, EnBW entered a contract with the consortium comprising General Electric (GE), engineering and technology company SENER, and general contractor Bonatti. The consortium is tasked with constructing a CHP plant at the Heilbronn site including related maintenance and support works.
The contract for supplying the H-Class natural gas-fired combined-cycle power generation equipment was awarded to GE Vernova in November 2023. The contract encompasses equipment supply, plant design and construction, software solutions, maintenance and services for ten years.