An essential part of energy system transformation is the storing of energy from fluctuating generators by various storage systems suitable for the application, in considering of an intelligent energy use and increasing energy efficiency. In addition, a redox flow storage system was procured and set up to simulate future grid situations at KIT in the real laboratory. The main idea of such a storage system is to decouple the electrical power from the storage capacity; the system topology of a redox flow battery allows the stored energy to be scaled independently of the storage capacity, as the amount of electrolyte in the tanks or the size of the tanks is flexible.
The redox-flow storage system installed in April 2019, consisting of an energy part (electrolyte tank), a power part (electrochemical cells and DC/DC conversion) and a grid connection part (DC/AC conversion) in separate containers, has a nominal output of 200 kW and a nominal energy content of 800 kWh. To integrate the storage facility into the KIT test infrastructure, a higher-level control and data acquisition system was developed. This allows various operating strategies to be implemented.
In the first step, the redox flow storage is primarily used to store the PV energy to limit the power fed into the grid and to make the stored energy available for later use. In long-term, a common operating strategy for the redox-flow and lithium-ion storage will be developed in order to combine the properties and advantages of the two storage systems.
Contact Partner: Dr. Hardi Hoimoja