At Schuby, in Schleswig-Holstein, a large battery system is designed to absorb renewable electricity when the grid is receiving a lot of it, then feed it back when generation falls or demand rises. The project gives large-scale storage a concrete form, but its capacity alone does not tell us how long it can supply power, or what the electricity will cost when it is available.
Store the surplus, release it when it matters
Schleswig-Holstein, a region in northern Germany where wind power is highly developed, can produce more renewable electricity than it consumes at certain times. This mismatch between generation and demand is one of the problems stationary batteries aim to address: they temporarily store some of the available electricity, then feed it back into the grid when it needs more.
The principle is not to generate energy. A battery shifts some of the electricity already produced from one time to another. It can thus help integrate wind and solar power more effectively, as their output depends on weather conditions, and provide flexibility to the grid. However, it does not replace power lines or all the resources needed to balance generation and consumption.
ECO STOR, the company developing the project, describes Schuby as a large-capacity storage facility. The published figures distinguish between two characteristics: a capacity of 238 megawatt-hours (MWh) and a power rating of 103.5 megawatts (MW). MWh measures the amount of energy that can be stored; MW indicates the rate at which the installation can charge or feed it back. The units therefore answer two different questions: how much can be stored, and at what power can it be delivered?
An installation sized for the grid
The project comprises 64 battery modules and 31 inverters, according to NORD/LB, which arranged its financing. The inverters convert electricity between the forms needed for storage and connection to the grid. ECO STOR says that proximity to a 110-kilovolt high-voltage connection was among the criteria for choosing the site. For an installation of this size, the grid connection is no minor detail: it determines whether the facility can charge and discharge at the planned power.
A capacity of 238 MWh does not mean that Schuby will constantly supply 103.5 MW. At maximum power, dividing capacity by power gives a theoretical discharge time of just over two hours. Actual operation depends in particular on the charge level, losses and operational choices. This distinction prevents a stored quantity from being confused with a guaranteed duration of service.
Private financing does not remove the obstacles
NORD/LB says it arranged the project’s financing and describes the structure as a private investment. ECO STOR says expected revenues are based on market mechanisms, despite regulatory uncertainties. This describes the business model being pursued, not a guarantee that the batteries will lower residents’ bills. Electricity prices fluctuate, and profitability depends on opportunities to store and then sell or feed back the energy, as well as on system costs.
The project also illustrates the importance of deployment conditions. A grid connection must be available in the right place and at the right time; initial investment is high; and the rules must allow operators to forecast their revenues. France Inter’s report also cites connection delays, administrative procedures and dependence on batteries made in China among the obstacles mentioned to wider development.
For Germany as a whole, NORD/LB recalls a target of around 100 gigawatts of storage power by 2030. This is a target for storage power, not an energy capacity expressed in MWh. Reaching this scale therefore means multiplying projects, but also building suitable grid connections and financing models.
Local benefits to monitor
At Schuby, the question is not limited to balancing the grid. ECO STOR says German tax rules were amended from the 2025 tax year so that 90% of the trade tax linked to storage facilities goes directly to the municipalities where they are located. For the municipality, this offers the prospect of local revenue, in addition to the jobs and economic activity the mayor hopes the project will attract to the region.
These benefits nevertheless depend on the activity actually generated and the tax revenue actually collected. A battery power station does not automatically create a new industrial base. Its immediate contribution is judged first by its ability to store and feed back electricity under the planned conditions; its local economic effects will be measured over time.
Schuby is therefore a concrete, financed and carefully sized project, but it is not in itself enough to demonstrate that batteries can solve the problems of an entire electricity system. Rather, it shows what innovation must achieve to move from principle to practice: connect to the grid, operate in line with real needs and find revenues capable of supporting the investment.
References
- ECO STOR, Schuby storage project
- NORD/LB, financing for the battery storage project in Schuby
- France Inter, report on the Schuby batteries
Battery storage at Reid Gardner, Nevada. Stock photo.
