Electric Thermal Energy Storage

Electric Thermal Energy Storage

GWh scale & for different applications

Setting new standards in flexible energy storage
With renewables expanding, securing stable energy supply in volatile weather conditions remains a challenge. Siemens Gamesa presents a flexible, cost-competitive solution: Electric Thermal Energy Storage (ETES) can store surplus energy for when it’s needed most.
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Are you interested in this flexible electric thermal storage solution? Please contact our team for further information.

Nominal power
> 100 MW
> 1 GWh
Experience since
80% off-the-shelf
Key Facts
  • Solution for 100% renewable energy use, in response to a marked need
  • Cost-competitive and innovative; capital expenditure is up to ten times lower than batteries
  • Compared to batteries, no hazardous materials are used
  • Charging, discharging and storage can be independently scaled; storage duration is up to two weeks
  • Efficiency is maintained: 98% while storing heat, up to 45% at full-electric cycle
  • ETES offers a flexible solution for different industry scenarios, from renewables to conventional power plants

Recommend for

Large scale and flexible energy storage for renewable energy plants, combined heat and power, and second-life option for conventional power plants.

ETES applications
ETES:Base make renewable assets into a steady energy supplier and increase revenue streams
ETES:Add make existing industrial plants more flexible and reduce emissions and service costs
ETES:Switch convert power plants into storage facilities and materialize stranded assets

One for all

Flexible storage solution for a broad range of applications

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 up to 600°C. 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.


Thermal energy storage: How does it work?

The road ahead

ETES brings economies of scale and the advantages of retrofitting
Thermal energy storage application ETES

The cost of ETES will be significantly lower than classic 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. Implementation of ETES:Switch will lead to a further cut in CAPEX of around 50%.

  1. Models developed and validated from 2012
  2. The first test site with 5 MWh capacity was implemented in 2014
  3. Proof of system starts operation with 120 MWh capacity in 2019
  4. A pilot plant with an output of ~50 MW will follow in 2020
  5. Commercial rollout is planned with an output of several hundred MW


A flexible and reliable technology
The Future Energy Solution project puts ETES to the test

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 power
  • 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.

Thermal storage application in Germany built in 2014
The Hamburg site shows the commercial opportunities for ETES
A real scale pilot demonstrates ETES effectiveness

The 24-hour thermal energy storage site is commissioned in 2019 Hamburg, Germany.

  • Storage capacity of 120 MWh is available day and night
  • Over 1,000 tons of rock provide 130 MWh of electric energy at temperatures of 600°C
  • The heat is re-converted into electricity through steam
  • A generator rated at 1.4 MW produces energy for up to 24 hours
  • Funded by the German Ministry for Economic Affairs and Energy


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