Planned facility will have 100 megawatt-hours capacity and 100 megawatts output, enough to supply a small town / construction of battery storage facility planned for early 2025
Marbach (Ludwigsburg district). A battery big enough to power a small town for one day: EnBW is installing a large-scale battery storage facility at its power plant site in Marbach, southern Germany. To give an idea of its size, the facility will have a capacity of 100 megawatt-hours (MWh) and an output of 100 megawatts (MW) – enough to meet the electricity needs of around 12,500 households for 24 hours. Rather than actually being used to power a single town, however, it will be connected to the TransnetBW transmission network, making it a key component of the southern German electricity grid. It will be by far the largest battery storage facility in EnBW’s generation portfolio to date. Construction of the facility is due to begin next year. It is expected to be operational by the end of 2025.
Key component of the future energy supply
“As the proportion of electricity generated from renewable sources such as wind and solar power increases, it becomes more and more important to be able to store energy and make it available at a later point in time,” explains Michael Class, Head of Generation Portfolio Development at EnBW. This dispatchable capacity, which can be made available on demand, plays a key role in the transformation of energy generation for the future. It makes it possible to match the supply of electricity from renewables – which varies with the weather – with the actual level of demand on the grid.
Arnim Wauschkuhn, Director Battery System Solutions at EnBW, explains the role and function of battery storage facilities such as the large-scale system planned at Marbach: “They store electricity from the grid when plenty is available and can feed it back again in a matter of seconds when needed.” This makes battery storage facilities an ideal addition to the dispatchable power system alongside, for example, pumped storage hydro plants and hydrogen-ready gas-fired power plants. The latter are needed for prolonged cold dark lulls, for example when there is neither wind nor sunshine for several days in winter. “This allows wind and solar power to work hand in hand with dispatchable generation capacity, making it possible to have a fully renewable energy supply,” adds Class.
Starting signal for EnBW’s large-scale battery project
“The timing for this project is ideal,” says Wauschkuhn. “Battery modules have become significantly cheaper. At the same time, there is increasing demand on the energy markets for short-term dispatchable capacity. Taken together, these two factors also improve the economics of large projects like this one.” The large-scale battery storage facility in Marbach will be equipped with lithium iron phosphate (LFP) batteries that contain no cobalt. The system is to be built on the southern part of the existing Marbach power plant site. EnBW plans to start construction of the battery storage facility in early 2025 and to connect it to the grid at the end of the year.
In the western part of the power plant site, EnBW is commissioning a grid stabilization system for TransnetBW’s transmission grid. This and the battery storage facility share the existing infrastructure on site, creating synergies for the project. An example is the grid connection.
Battery storage systems play an important role in EnBW’s generation business. They are included as standard in new solar park projects, for example, in order to feed power more flexibly into the grid. Storage systems of this kind have already been installed at several sites. “We are also planning further large-scale battery storage projects,” says Wauschkuhn.
