Model-Based Evaluation of Decentralised Electricity Markets at Different Phases of the German Energy Transition

The analysis is based on reviewing the following indicators that are derived from a model-based scenario analysis: CO 2 emissions of electricity generation; regional levels of self-supply with electricity; variable costs of electricity generation; grid congestion and grid expansion needs. The research question is twofold. Firstly, how does the size of decentralised markets affect the indicators mentioned. Secondly, which effects on these indicators can be observed if only power plants of a certain size or technology are allowed to take part in the decentralised markets.The analysis focuses on a system perspective and does not include effects on individual market players. In addition, it focuses on the electricity system with only some interactions with the heating or mobility sectors. The modelling work looks at the effects within the boundaries of a predefined scenario and for two scenario years. Dynamic effects such as a possible effect of decentralised markets on the overall deployment of RES-E technologies or storage systems is therefore not part of the analysis. The results are valid for the German electricity system and cannot necessarily be transferred to other countries or electricity systems with e.g. a weaker electricity grid or less interconnection to neighbouring countries.