IEA ES Task 44: Power-to-Heat and Heat integrated Carnot Batteries for Zero-Carbon (industrial) heat and Power supply

The rise of renewable energy causes fluctuating energy production. The electrification of heat supply further challenges the electricity grid. Coupling electricity and heating with thermal storage helps to strengthen grid resilience and ensures stable energy supply. This project identifies and evaluates heat-integrated Carnot battery concepts to store thermal and electrical energy and supply electricity and thermal energy on demand.

Short Description

The aim of the IEA ES Task 44 of the International Energy Agency is to examine the role of Power-to-Heat (PtH) applications and heat-integrated Carnot battery systems (PtHtP, see Figure 1) in the decarbonization of industrial processes and connected heat and power networks. For this purpose, suitable system concepts and use cases for different technology configurations are identified and evaluated. The following development steps are planned for the overall project:

  • Evaluation of available models of technology components for energy conversion and storage and overall systems
  • Development of KPIs for technology and system evaluation and comparison of technologies and systems
  • Documentation of demonstrators and applications of PtH and PtHtP systems
  • Development of prototype reference scenarios, technology mapping for new use cases and techno-economic evaluation
  • Development of recommendations for legislative framework conditions to increase the potential of implementation.

To represent the status quo, current applications of PtH and PtHtP technologies and systems are documented using fact sheets. Systems with sector coupling potential also for the discharge (combined heat and power, CHP), are specifically considered. Figure 2 shows a current application example. A classification of the applications (e.g. industrial supply, combined industrial/heat supply, pure electricity storage) provides a structured technology representation. Based on this, prototypical reference concepts will be developed that demonstrate the broad application potential of Pth and PtHtP.

The result will be a collection of reference scenarios for different applications of PtH technologies and PtHtP systems. The technologies of the reference scenarios will be presented in a comparable manner using KPIs. This allows future applications and implementation to be identified in a better way. Techno-economic assessments from the international task complement the envisioned technology mapping.


Austria, Belgium, Denmark, Germany (Operating Agent), Italy, Japan, Netherlands, Sweden, Switzerland, Spain, UK, USA

Contact Address

DI Dr. Wolfgang Weiß
AEE – Institute for Sustainable Technologies
Feldgasse 19
8200 Gleisdorf