FlowStore – A latent isothermal flow battery for industrial steam

FlowStore is a new concept for latent thermal energy storage (TES) based on salt. Latent storages have so far been limited in use because of the inherent low thermal conductivity of the storage materials. With FlowStore we circumvent this problem by transforming the storage into a flow battery turning the salt to a flowable slush inside a non-stick heat exchanger. Through this concept we can extract heat from solidifying salt in flow and therefore access the latent heat at pace on par with sensible TES. This results in heat delivered at high power which is necessary to serve peak heat demand in many industrial processes. Furthermore, because we utilize the latent heat of the salt, the heat input temperature does not need to exceed the heat output temperature required for a specific industrial process. This makes our flow battery very suitable for storing heat from sources where the achievable temperature is limited, such as concentrated solar power, high temperature heat pumps, and industrial excess heat and make it available for the industry to help them transition to green production and greatly improve their green energy fraction. In the project a first-of-its-kind small scale test setup is developed to prove the concept by generating 180C steam when discharging the flow battery.