By storing energy in chemical reactions, also known as thermochemical energy storage (TCES), it is possible to deposit energy without losses over long periods of time. In comparison to other technologies, the energy density is signicificantly higher. In RESTORE, TCES is used for both short- and long-term energy storage.

TCES pilot plant: A major success of the project is the development of a 5kWth continous reactor system by Technische Universität Wien (see picture) that can be operated up to 10 bars and 200 °C. The scale-up to 30 kWth is ongoing.

The chemical and thermophysical properties of numerous TCES materials were thoroughly analyzed, and the most optimal candidates were selected with energy densities up to 1.11 GJ/m³ suspension (or 2.07 GJ/m³ salt).

Various types of mineral, silicon and vegetable oils, individually and in combination with each other or additives, were evaluated, and the optimal combinations for reaction were determined;
thus, over 5 – 30 charging discharging cycles for 5 chemical systems was proven in lab-scale batch reactor (copper-sulfate and Potassium-carbonate among them).

Enhanced mass transfer and high heat transfer efficiency was achieved by designing innovative sparger systems, and by evaluating various impeller designs and agitation systems. Optimized preservation techniques were developed by the systematic examination of storage effects on TCES materials.

The systems modularity allows for easy scale-up to larger proportions.

Find out more about the TCES development in the results brochure.

5 kWth TCES pilot plant as continous reactor system (photo by TU Wien)