Research project examines the grid-friendly operation of decentralised battery storage

19.01.2022 Battery storage is becoming increasingly popular among customers with photovoltaic systems. This increases the interest of distribution grid operators hoping that such storage systems and their operation mode can contribute to network stability and optimisation. Researchers from the BFH Energy Storage Research Centre have analysed how great the benefit of decentralised, customer-side battery storage is for the distribution grid, how incentives can be created for a grid-friendly mode of operation and how such an operating strategy can be implemented. A final report presents the results of their research.

Netzdienlicher Betrieb von dezentralen Batteriespeichern

More and more Swiss people have their own battery storage at home, where they can store the energy generated by a photovoltaic system. The increase of decentralised photovoltaic systems and electric cars is a challenge for the stability of the power grid, since line overloads and voltage limit violations could occur if no measures are implemented. This could be avoided to a certain extent by operating the battery storage systems in a grid-friendly way. Together with Groupe E, WWZ and Swissolar, researchers from the BFH Energy Storage Research Centre used simulations to investigate the benefits of this operating strategy and the remuneration options available as an incentive for the owners of the storage systems. Likewise, the emulation environment Prosumer-Lab of Bern University of Applied Sciences showed how a grid-serving operating strategy could be designed and technically implemented. The project received funding from the Swiss Federal Office of Energy (SFOE).

Local variations

The research has shown, among other things, that the effect of grid-serving battery storage varies in size depending on the location. Especially in the case of inhomogeneous distribution network structures, often found in urban and rural regions, individual storage systems at relevant locations can have a large positive effect, while others have little impact. In more homogeneous networks, as was the case in the suburban grid studied in this project, the exact location is less relevant, as overloads tend to occur there in main supply lines and in the transformer station.

The grid-serving use of storage systems significantly reduces the load on the power grid. However, the financial value of operating a storage facility in a grid-serving way is small compared to the cost of the storage. This is due to the comparatively lower network reinforcement costs. Creating a direct monetary incentive for battery operators would thus prove difficult. However, the researchers see a possibility in not paying each storage a flat rate, but rather according to the individual value of the storage facility for the distribution grid. Targeted remuneration could be higher and create a greater incentive. However, this is unlikely to be easy to implement in practice. New tariff models for consumption and feed-in that better reflect the use of the power grid than today’s tariffs have the potential to provide greater incentives for grid efficiency in the future.

The project final report is available here:

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