Co-Simulation of Multimodal Energy Systems Our mission is to support the transition towards renewable and digitized energy systems with open-source co-simulation tools.
The energy transition fundamentally changes the way our energy supply works. It changes from a centrally controlled system with few large and well controllable power plants towards a system with many distributed energy resources which work on renewable and volatile sources. Additionally, the number of larger electricity consumers in the distribution network increases due to electric mobility and the electrification of the heat supply.
As part of this transition, the complexity of the previously central and low-data energy supply system increases inevitably. The future dynamic of the system arises as a result from the interaction of decentralized energy resources, weather, market mechanisms, local energy storage, new consumption patterns (e.g. electric mobility) and the coupling of formerly separated energy sectors (e.g., electricity grids, gas grids, and heat networks). The figure below illustrates this transition in a simplified example. To ensure the optimal energy supply with these complex interactions, the development of an information and communication technology (ICT) infrastructure with extensive information sharing is necessary.
For the development and integration of such ICT-systems and decentralized energy resources, an approach with multiple steps is used. The first concepts of new technologies are typically tested with analytical methods, while comprehensive field tests are at the end of the development process. In-between these two steps, methods are needed which are cheaper and more flexible than field tests, but are also able to model the system complexity better than analytical approaches. The group “Smart Grid Testing” (SGT) is specialized in simulation-based system analysis for the development and validation of new components and architecture for the energy supply system.
What is Co-Simulation?
For the simulation of systems, multiple approaches can be applied. One common option is to model the whole system with all of its components in one simulation tool. Nevertheless, this comes with the drawback that it is difficult to reuse the components and that all components have to be developed together. Especially in complex systems with many components, this approach often exceeds the capacities for one development project. Additionally, a single tool often is not the best choice for modeling all different components. Therefore, co-simulation uses the approach to couple different simulation models and components to represent the whole system. In the domain of energy systems, there are for example the energy grid, renewable electricity generation, weather data, a market simulation, a consumption simulation or a simulation of the ICT components. As depicted in the following figure, these components are coupled via a common framework. This framework does the orchestration and enables the communication between the simulators. This task can, for example, be done by our tool “mosaik”.
Example of a grid simulation
Some examples of the central building blocks of a co-simulation are mentioned above. When these components work together, insights can be generated which would not be possible if the single components are only used on their own. This can be seen in the example below. Here, solar power systems, a simple grid as well as private households as consumers are simulated together. Combined with weather data, it can be observed which parts of the grid are overloaded. Using this approach, scenarios can be build to analyze future developments and to calculate necessary adjustments in the grid. Our contribution for these simulations is the simple and flexible possibility to combine different components such as grid, solar, and household models, among others. Additionally, we work on the framework to allow the integration of control algorithms, e.g., to manage the behavior of a battery system. Generally speaking, we work on the generic framework for co-simulations.
If you want to try the example, you can do so here: https://mosaik.offis.de/live-demo/
mosaik Community
We work in the core functionality of mosaik to extend the possibilities and usability of co-simulations. We do the whole development of mosaik open source, so that we allow researchers worldwide to run co-simulations. With the tools that we develop, the researchers can analyze scenarios in the energy context more simply and in more detail, but are not limited to the energy domain. We invite external developers to take part at the development of mosaik. The repository can be found here: https://gitlab.com/mosaik/mosaik
Topics for future developments are, next to the usability and performance, also simulation-as-a-service, distributed simulations, automaton of simulation and platforms to share simulation models.
More information about mosaik can also be found on its website: https://mosaik.offis.de/
Development of the mosaik ecosystem
A strength for mosaik is the large number of adapters to other tool and models for different components. Among others, these are pandapower for grid calculations, OMNeT++ for communication simulation as well as adapters to connect Matlab, Java, and other programming languages. We continuously extend this ecosystem to extend the possibilities of mosaik. Large parts of the mosaik ecosystem can be found here: https://mosaik.readthedocs.io/en/latest/ecosystem/index.html
Application of mosaik for Scenario Creation
If it’s the building process of a hydrogen economy or the analysis of scenarios for future urban neighbourhoods: we use mosaik and its ecosystem to model and simulate new scenarios to gain new insights in future energy systems. Additionally, by using mosaik we can gain insights in the strengths and weaknesses of mosaik and can better plan the further development of the tool.
Flagship Projects
REMARK
The REMARK project aims to develop an mosaik-based end-to-end usable toolbox for the specification, simulation and analysis of the interaction of ancillary service markets, market participants and digitalized energy systems in terms of resilient system design and system operation. This toolbox will assess feedback effects between market rules, participant behaviour, digitalization levels, and grid resilience to support resilient energy system design and operation.
ReCoDE
In the ReCoDE project, we develop a co-simulation platform to make studies from current and future use cases in digital energy systems possible. The integration of these use cases into existing reference models (for energy systems, communication systems, and market mechanisms) and reference scenarios (relevant time series and parameters for specific models) as well as the further development of the reference models and scenarios is of high importance. Existing tools, which are already standard in the field (e.g. mosaik, SIMONA, OpSim, pandapower, OMNeT++/ns-3), will be made interoperable so that simulation chains are consistently usable. Especially the integrated simulation of information- and communication technology allows for new analysis possibilities for the aspects of robustness and resilience of innovative automation approaches in the energy system.
NFDI4Energy
NFDI4Energy aims to establish open services that assist energy researchers in typical tasks like finding the right data and software and managing them. It seeks to simplify the identification and coordination of simulation-based tools, making simulations more accessible to a broader range of researchers. Mosaik will be extended and directly integrated into the open services.
Contact persons
Further information
- https://gitlab.com/mosaik
- https://mosaik.readthedocs.io
- https://github.com/orgs/OFFIS-mosaik/discussions
- https://mosaik.offis.de
Publications
Persons 
S
O
K
Dr.-Ing. Jirapa Kamsamrong
E-Mail: jirapa.kamsamrong(at)offis.de, Phone: +49 441 9722-233, Room: E85
A
Sharaf Aldin Alsharif
E-Mail: sharaf.aldin.alsharif(at)offis.de, Phone: +49 441 9722-748, Room: Flx-E
Publications
2025
Load-shifting for cost, carbon, and grid benefits: A model-driven adaptive survey with German and Swiss households
Matteo Barsanti and Jan Sören Schwarz and Faten Ghali and Selin Yilmaz and Sebastian Lehnhoff and Claudia R. Binder; Energy Research & Social Science; 01 / 2025
Towards an Ontology for Co-Simulation Scenarios of Energy Systems
Schwarz, J. S., Steinert, A., Fuentes Grau, L., Pan, Z., Schmurr, P., Liu, N., Seiwerth, C., Qussous, R., German, R., Hagenmeyer, V., Lehnhoff, S., Monti, A., Nieße, A., & Weidlich, A.; 2. NFDI4Energy Conference; 03 / 2025
2024
How can Aggregators Improve the TSO-DSO-Customer Coordination in Digitalised Power Systems?
Otte, Marcel and Kamsamrong, Jirapa and Lehnhoff, Sebastian; ISGAN 2024; July / 2024
A Toolbox for Design of Experiments for Energy Systems in Co-Simulation and Hardware Tests
Schwarz, Jan Sören and Perez, Leonard Enrique Ramos and Pham, Minh Cong and Heussen, Kai and Tran, Quoc Tuan; 2024 Open Source Modelling and Simulation of Energy Systems (OSMSES); 09 / 2024
Challenges in Transitioning from Co-simulation to Practical Application: A Case Study on Economic Emission Dispatch in a Greenhouse Compartment
Clausen, Christian Skafte Beck and Lehnhoff, Sebastian and Schwarz, Jan Sören and Jørgensen, Bo Nørregaard and Ma, Zheng Grace; Energy Informatics; 2024
Enhancing Smart Grid Resilience: An Educational Approach to Smart Grid Cybersecurity Skill Gap Mitigation
Pirta-Dreimane, Rūta, Andrejs Romanovs, Jana Bikovska, Jānis Pekša, Tero Vartiainen, Maria Valliou, Jirapa Kamsamrong, and Bahaa Eltahawy; Energies; April / 2024
Hardware-in-The-Loop-Based Validation of Distribution System Control Applications with Grid Operators, Customer and Market Participants
Otte, Marcel and Krüger, Carsten and Das, Pratyush and Rohjans, Sebastian and Lehnhoff, Sebastian; Energy Informatics Academy Conference; October / 2024
Poster Abstract: Coordinating the Heterogeneity of Aggregators in Digitalised Power Systems
Otte, Marcel; DACH+ Conference on Energy Informatics 2024; October / 2024
Poster Abstract: Hardware-in-the-Loop Simulation Environment for Validating Distribution System Control Applications
Otte, Marcel and Krüger, Carsten and Das, Pratyush and Rohjans, Sebastian and Lehnhoff, Sebastian; DACH+ Conference on Energy Informatics 2024; October / 2024
Scaling Analysis in a Multi-Energy System
Schwarz, Jan Soeren and Pham, Minh Cong and Tran, Quoc Tuan and Heussen, Kai; 2023 Asia Meeting on Environment and Electrical Engineering (EEE-AM); 01 / 2024
