Eindhoven company will test heat battery with salt and water later this year
Cellcius, a spin-off of TNO and TU/e, will test a heat battery based on salt and water in four houses later this year. The batteries can store 70 kWh of heat and are intended, for example, to bridge a period of ‘a few days’ without energy.
The battery is based on potassium carbonate and water, and works by adding water to the salt crystals. When the salt crystals absorb water, they become larger and heat is released. A heat exchanger removes the heat from the system and allows users, for example, to heat a house or take a hot shower. With this heat exchanger, the salt crystals can be heated, so that the salt is heated dry and energy is therefore stored in the salt crystals.
The 70 kWh heat battery will be tested in four homes in a first pilot later this year. Two of these will be located in Eindhoven; the other two are in Poland and France. According to Cellcius, a family with the battery should be able to bridge ‘a few days’ without solar or wind energy. With the pilot, the researchers want to learn what is needed to be able to use the battery on a large scale and whether the user wants an app to control the battery, for example.
In addition to the 70kWh heat battery, Cellcius has developed a 200kWh prototype, consisting of approximately thirty ‘lockers’. These lockers are separate containers with salt, so that the battery does not have to be used completely in one go.
Cellcius not only wants to heat individual houses with the heat battery, but is also thinking about reusing industrial residual heat. For example, the start-up wants to store residual heat from the Chemelot Campus in Sittard-Geleen in the heat battery and then move it to a ‘transformer house’ in a residential area within the same municipality. This transformer house will then provide about fifty homes with heat via pipes. This pilot should start ‘in the course of next year’. Cellcius was founded at the end of 2020 and is a spin-off of TNO and TU/e. The company now employs five people.
Photo: Bart van Overbeeke