Electric Thermal Energy Storage
GWh scale & for different applications
One for all
The transition toward renewable energy brings new challenges. From grid stability to the need to become ever more energy efficient, to the abundance of conventional power plants: Siemens Gamesa has found an intelligent solution to the different challenges with ETES.
ETES draws electricity from the power grid and uses it to heat volcanic stones to temperatures of 600°C and higher. That heat can be converted back into electricity using a conventional steam turbine. The system is built on 80% off-the-shelf components and can function alone, be added to an existing heat cycle or convert a thermal power plant into a storage plant.
The road ahead
The cost of ETES will be significantly lower than other energy storage solutions. Even at the pilot stage, a commercial project at GWh scale would be highly competitive compared to other available storage technologies. Economies of scale will bring substantial reductions in capital expenditure, while increasing the storage rating.
- Models developed and validated since 2012
- The first test site with 5 MWh capacity was implemented in 2014
- Proof of system starts operation with 130 MWh capacity in 2019
- A pilot plant with an output of ~50 MW will follow
- Commercial rollout is planned with an output of several hundred MW
The concept of electric thermal energy storage has been extensively tested since 2014. First models developed and validated from 2012.
- Technical specifications were set at 700 kW charging power and 5 MWh storage capacity
- The project achieved 95% heat storage efficiency
- Optimizing control algorithms resulted in a 10% increase in storage
- This process has led to a considerable amount of property rights so far.
The 24-hour thermal energy storage site is commissioned in 2019 Hamburg, Germany.
- Over 1,000 tons of rock provide thermal storage capacity of 130 MWh of electric energy at rated charging temperatures of 750°C
- The heat is re-converted into electricity through steam
- A generator produces electricity of about 1.5 MW
- Funded by the Federal Republic of Germany Funding authority: Federal German Ministry of Economic Affairs and Energy due to a decision of the German Bundestag