Context

The increasing integration of Renewable Energy Sources (RES) into the power grid introduces significant challenges in congestion management at transmission level. The growing integration of flexible assets in the electricity system (conventional thermal generation, but also new types of loads like batteries, electric vehicles, flexible demand…) is expected to provide services to help ensure adequacy at any time. On the other hand, TSOs are expected to expand the grid to ensure a smooth integration of new production and demand, yet the grid will be operated closer to its limits to avoid costly investment costs.

Stationary Battery Energy Storage Systems (BESS) are a well-suited option for short term flexibility needs (in the range of seconds to hours) including services to the grids. Because of cost reduction, supply chains and technology improvements of automotive and various applications, the overall worldwide rechargeable battery market has exploded in the last decade.

Currently, BESS (residential, commercial or industrial scale), with 36 GWh globally installed capacity, only plays a limited role in the overall demand for batteries (~7%). Still, their impact on grid management is already visible and can be improved: In BESS management (and for any type of flexibility source), the interactions between actions taken to ensure adequacy at any time and actions to alleviate constraints on the transmission grids are often overlooked. For example, the activation of a BESS resulting from day ahead markets can cause congestions; on the other hand, a battery can be used to solve a constraint in the network, which needs to be compensated. This gap needs to be tackled to ensure an effective use of the grid while maximising the potential of flexible assets.

The use of BESS for congestion purposes heavily depends on the overall congestion management process itself and on regulation. In France, RTE follows a centralized balancing approach with advanced simulation-based congestion management, complemented by topological actions to reduce redispatch needs. In contrast, Germany relies on a more market-driven system, featuring liquid intraday markets and reduced reliance on TSO-activated reserves.

Objectives

The goal of this project is to optimise the interactions between adequacy and network services at transmission level, from D-1 to real-time, in particular in areas where flexible assets are expected to be present, and to develop advanced methodologies for managing grid congestion; e.g. by anticipating the risk of BESS flows leading to congestions on the transmission network and propose signals from TSOs to BESS owners for them to react accordingly.

In addition to advancing techno-economic solutions, the project will include an in-depth analysis of current and future reserve and congestion management regulations in France and Germany. This comparative study will highlight similarities and differences, providing insights into the regulatory frameworks’ influence on market dynamics, actor strategies, and operational decisions. The findings will give recommendations for aligning regulatory incentives with system needs and improving market efficiency.

Project partners

The project involves the University Duisburg-Essen and two industrial partners (RTE and Swissgrid).

Credits: Pictures are from Matthew Henry from Unsplash (Unsplash license) and Wikipedia Commons (CC0 1.0 license).