ALEGrO – Market Integration und System Operation Aspects of the new HVDC link between Germany and Belgium

The German Transmission System Operator (TSO) Amprion and the Belgian TSO Elia commissioned a new 90-kilometer-long HVDC interconnection between Germany (DE) and Belgium (BE) in November 2020. The project is called Aachen Lüttich Electricity Grid Overlay or “ALEGrO”. This new interconnector is the first and only electrical connection between BE and DE. The transport capacity of ALEGrO is 1.000 Megawatt (MW). Due to the project’s outstanding role with regard to European electricity system and market integration, ALEGrO has been funded by the European Commission’s TEN-E-Programm and has been included in the list of Projects of Common Interest (PCI) of the European Union. From a technical point of view this new HVDC link is a pioneering project: It is the first HVDC based tieline implanted into a highly meshed, synchronously operated AC transmission grid in the the middle of continental Europe. This comes along with diverse particularities and challenges in Market Integration and System Operation, which are described in this paper.