IEA ES Task 36: Carnot Batteries

Carnot Batteries are an emerging technology for the inexpensive and site-independent storage of electric energy at medium to large scale (> 1.000 MWh). The technology transforms electricity into thermal energy, stores it in inexpensive media such as water or molten salt and transforms the thermal energy back to electricity as required. Carnot Batteries have the potential to solve the global storage problem of renewable electricity in a more economic and ecologic way than conventional batteries.

Short Description

Although several concepts have been proposed for Carnot Batteries, a comprehensive techno-economic assessment of this technology has yet to be developed. Only a few laboratory or plant-scale demonstration facilities exist that provide the energy storage community with scientific data. The establishment of an international platform to bring together experts from industry and academia in a structured way, that assesses the state of the art of R&D for Carnot Batteries, deepens the understanding of their possible role in the future energy system and makes Carnot Batteries internationally visible would greatly strengthen the community.

The overarching aim of Task 36 is to ease the transition from a fossil-fuel to a renewable source-based energy system, through the promotion of novel energy storage systems, assisting their development, deployment, demonstration and their deep understanding. Therefore, it aims to establish a platform that brings together experts from the industry and academia, to systematically investigate, assess and strengthen the potential role of Carnot Batteries in the future energy systems, gaining international attention. The key objectives of Task 36 are:

  • Mapping of the main Carnot Batteries technologies and applications through the collection of existing information on electricity storage systems based on thermal energy storage.
  • Developing technology Key Performance Indicators of the Carnot Battery systems and their key components.
  • Critical assessment of technological competitiveness and R&D demand.
  • Helping technologies to market and delimit the market reach by identifying the services that should/can be provided by Carnot Batteries
  • Informing policy and providing a basis for proper regulations, based on the benefits and potential of Carnot Batteries and the requirements for assisting their deployment.
  • International dissemination of the technologies through workshops, white paper, open-source datasets and scientific papers

The scope of the Task will be restricted to the conversion and storage of electricity in the form of thermal (sensible, latent and thermochemical) energy. Other technologies such as electrochemical and mechanical storage technologies are excluded.


Austria (Expertenentsendung), Belgium, Czech Republic, Denmark, France, Germany (Task Manager), Italy, Japan, Netherlands, South Korea, Sweden, Switzerland, Turkey, UK, USA

Contact Address

DI Christoph Rohringer
AEE – Institute for Sustainable Technologies
Feldgasse 19, 8200 Gleisdorf