Research project

Model comparison for impact analysis of policy instruments (MODEX-POLINS)

The “model comparison for impact analysis of policy instruments” project (POLINS) is one of six MODEX projects founded by the German Federal Ministry for Economic Affairs and Energy, with a project grant of 550 thousand euros between 2019 and 2021.

Energy research is often based on complex computer models. The aim of all MODEX projects is a methodological comparison of energy system models, profound exchange among model developers, and eventually a quality improvement of the models. The POLINS project focuses on policy instruments, of which the assessment is compared across the models of the five project partners. In particular, the German coal phase out, carbon pricing, and support schemes of combined heat and power are investigated.

The Hertie School participates in MODEX-POLINS with the electricity market model EMMA. Considering the different policy options, the model simultaneously optimises investment and dispatch of power generation, storage, and transmission in the interconnected European power system. This allows for assessing the implications of policy instruments, such as on carbon emissions and electricity prices. EMMA distinguishes itself within POLINS through being completely open-source.

Process and milestones: Initially, the project partners developed a joint reference scenario for the years 2016, 2025 and 2030. On this basis, the first model experiment on the German coal phase-out is running since September 2019. Two other experiments follow on carbon pricing and on support schemes of combined heat and power. In addition to a final report, the project partners aim for scientific publications.

Expected results: We made significant progress in the development of EMMA. The most important improvements concerned the technological detail, the geographical scope, and the representation of future scenarios.  Furthermore, we are planning to publish EMMA on GitHub and implement a version control system. The comparison with the other models of the project partners revealed interesting differences, which will be described and discussed in a scientific article soon.


Universität Duisburg-Essen (Lead)

ewi Energy Research & Scenarios gGmbH

Fraunhofer-Institut für Energiewirtschaft und Energiesystemtechnik IEE

Öko-Institut e.V.


Federal Ministry for Economic Affairs and Energy (Germany)


1 January, 2019 – 31 December, 2021.

Project grant

Total: 550.000 euros

Hertie: 92.000 euros

Staff members

  • Prof. Dr. Lion Hirth, Assistant Professor of Governance of Digitalisation and Energy Policy

  • Oliver Ruhnau, PhD researcher and Research Associate to Prof. Lion Hirth.