20.10.2025

DFG: Priority Programme “Carnot Batteries: Inverse Design from Markets to Molecules”

Deadline: 3 February 2026

In March 2022, the Senate of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) established the Priority Programme “Carnot Batteries: Inverse Design from Markets to Molecules” (SPP 2403). The programme is designed to run for six years.

The present call invites proposals for the second three-year funding period.

The affordable, site-independent and resource-saving storage of electrical energy in the societally relevant order of magnitude of gigawatt hours (GWh) is the central unsolved problem in the transition to fluctuating renewable energy sources. One possible solution could involve the Carnot battery technology, which converts electrical energy into heat by means of high-temperature heat pumps, heat being stored in cheap materials as internal energy and then converted back into electrical energy when required, e.g. by means of steam turbines. The underlying thermodynamic principle has been known for a long time, however, there are still no general methods for designing or analysing Carnot batteries based on their fundamental properties and objectives. Carnot batteries are complex, coupled, time-varying systems with a large number of components and degrees of freedom. Published efficiencies and costs are poorly verified or apply only to specific systems; the integration into future energy markets is unexplored.

The intrinsically new approach proposed by the SPP is a comprehensive inverse top-down design methodology, starting from the target variables (market) all the way down to the individual components (machines, storages and fluids, i.e. molecules) and their coupling, aiming at their optimal design and operation.

This approach sets a completely new course with respect to today's design methodology, which – based on known components and circuits – seeks to determine target operation parameters, e.g. efficiencies, and implements the optimal case identified in a very limited parameter space.

The working hypothesis of the Priority Programme is: “Through a paradigm shift towards an inverse design methodology, it is possible for the first time to test the feasibility of storage efficiencies above 70 percent and market-compliant storage costs using thermodynamic principles and to assess their compatibility with energy markets”. This hypothesis is to be assessed by an interdisciplinary team representing the fields of energy system analysis, thermodynamics, heat transfer, fluid energy machines, numerical optimisation and physical chemistry in close cooperation between universities and research centres (DLR). This is to be done in the inversely arranged research areas:

• A: Carnot batteries in energy markets
• B: Design of Carnot batteries and
• C: Components for Carnot batteries

In the first period, the focus lay on the development of steady-state fluid-dependent models for Carnot batteries, machines and storages and the implementation of inverse design approaches, including a proof of concept. In the second period, it is planned to use these models in cooperations and to refine them with respect to the ability of predicting transient behaviour and the inclusion of sub-models or multiple objectives from the other research areas.

Project proposals in these areas are expected to show a close connection with at least one of the projects from the other research areas in order to establish an inverse and transferable top-down design methodology with quality and assessment criteria defined by the energy system analysis.

If interested applicants need support in finding project partners or need further information, they are invited to contact the coordinator.

Proposals must be written in English and submitted to the DFG by 3 February 2026.

The DFG strongly welcomes proposals from researchers of all genders and sexual identities, from different ethnic, cultural, religious, ideological or social backgrounds, from different career stages, types of universities and research institutions, and with disabilities or chronic illness. With regard to the subject-specific focus of this call, the DFG encourages female researchers in particular to submit proposals.

Further information:
https://www.dfg.de/en/news/news-topics/announcements-proposals/2025/ifr-25-66