Energy company EnBW Energie Baden-Württemberg AG has commissioned MAN Diesel & Turbo to build a 30 MW gas-engine combined heat and power (CHP) plant at its Stuttgart-Gaisburg site. The plant will be powered by three MAN 20V35/44G gas engines and in addition to its electrical output will also provide up to 30 MW of district heating. With up to 90% overall efficiency, the plant will have a particularly high fuel utilisation rating.
The power station project is part of the comprehensive modernisation of the Stuttgart-Gaisburg site. Alongside the CHP plant, EnBW will be building a heat storage facility and a boiler system with a thermal output of up to 210 MW to enable peak and reserve shaving. The existing coal power station is to be decommissioned. The new installations will be operational by the end of 2018.
“This recent investment decision to build a new power plant is an important contribution to the urban energy transition. The modernisation will reduce local CO2 emissions by up to 60,000 tonnes per annum”, says Diana van den Bergh, Project Manager at EnBW.
EnBW had commissioned MAN Diesel & Turbo to plan the engine cogeneration plant as early as July 2016. However, the final decision to go ahead with the project was only made after approval and clearance by the German government and the European Commission with regard to CHP legislation. “With the new German CHP Act passing into law, there is finally legal certainty again for power-plant investors in Germany. The development of CHP is vital not just for the energy transition but also for Germany’s climate protection goals”, says Dr Tilman Tütken, Vice President MAN Diesel & Turbo and European Head of Sales Power Plants.
“Large-scale gas engine power plants are a relatively new technology for the German market but one that has significant benefits for operators, especially in energy systems handling large quantities of fluctuating renewable energy”, affirms Tütken. “The Gaisburg project is using our modular power plant concept for CHP facilities. The modular design can be scaled up from 7 MW as required.”
The reaction speed and operational flexibility of the system is another advantage for power plant operators. MAN gas engines can reach maximum output in considerably less than five minutes and can also cope with rapid load changes without any problem.
The heart of the CHP solution is the MAN 35/44G, a four-stroke gas engine with options for single or two-stage turbocharging. In two-stage (TS) versions, a low-pressure and high-pressure compressor are arranged in series, thus boosting engine efficiency. The 20-cylinder version has a mechanical output of 10 MW in the single-stage design and 12.4 MW in the two-stage variant. The TS version is also available as a 12-cylinder V-type with a mechanical output of 7.4 MW.