Renewable Energy

Thermal Battery

The production of renewable energy depends heavily on the availability of sun and wind. Decoupling energy production from consumption by storage is crucial for a global strong expansion of renewable energies.

The HTTES system provides an inexpensive and very efficient way of storing electrical energy from renewables.

We developed two different systems to store energy:

Thermal Battery with ORC/steam cycle

With this system electricity to electricity efficiencies of 35-45% are possible. The main advantage lies in low investment costs when using established technologies available on the market (waste heat boiler, steam turbine etc.).

With Power to Heat, the heat is stored at a high temperature-level in the HTTES system.



The modular system allows for storage capacities in the range of MWh to GWh with very high thermal power, so that the storage can be fully charged and discharged within a few hours.


The thermal energy in the HTTES is fed back into the grid with a classic steam process or an ORC. (Heat to Power)



Pumped Thermal Energy Storage

With this system, realistic electricity to electricity efficiencies of up to 60-75% are possible. Therefore, this system is ideal for storing surplus electricity. When compared to battery storage, this system has the advantage of significantly lower investment costs and longer service life.

Using a Joule process/Brayton cycle (similar to a high-temperature heat pump), electrical energy is converted to thermal energy and stored in a hot and a cold STORASOL-HTTES.






In the hot STORASOL-HTTES, the heat is stored at up to 800 °C for several hours or days.
In the cold STORASOL-HTTES, the heat is stored at up to -100 °C for several hours to days.
By reversing the same Joule process/Brayton cycle, the thermal energy from the energy stores (hot and cold HTTES) is converted back into electrical energy and fed into the grid.