Cracking codes for renewable integration
The German demonstrator within the EU-SysFlex project has designed a process to include decentralised power sources as flexibilities for solving congestions to ensure smooth and flexible RES integration into the grid.
The EU Decarbonisation plan can only be achieved by increasing the share of renewable energy resources (RES). Germany already had a share of roughly 50% in RES in the first half of 2019 regarding the gross electricity generation.
An even higher share of RES is expected in the following years, as the German government aims at 65% RES till 2030. In the area of the German demonstrator we already have more than 100% share of RES in consumption. As a result, the electricity supply is becoming more variable, creating uncertainties and technical challenges not previously seen in the pan-European electricity system.
The nature of these renewable energy resources will require that the structure of Europe’s power grid changes to offer the flexibility and responsiveness it will need to manage the higher complexity of the system. Therefore, advanced coordination mechanisms between distribution system operators (DSOs) and transmission system operators (TSOs) are needed.
In order to address these challenges, the EU-SysFlex project was launched in November 2017. The four-year project brings together a unique consortium of 34 members from 15 countries across Europe in a joint effort to build seven demonstrations. Using members’ unique industry expertise and experience (which includes transmission system operators, distribution system operators, aggregators, technology providers, research and academic institutions, as well as consultancies), these demonstrations have been working to identify and solve the problems surrounding the continent’s future energy supply. The total budget for the project is €26.5 million of which €20.5 million are funded by the EU Commission in the framework of the Horizon 2020 program.
framework through its efforts to propose system and flexibility solutions. This includes making practical improvements across all system sectors, creating a long-term roadmap of actions to facilitate the large-scale integration of new technologies and capabilities.
Increasing the flexibility in the pan-European system requires a comprehensive and all-encompassing vision that extends across a broad portfolio of new approaches, solutions and technologies. EU-SysFlex provides this by demonstrating different business use cases in seven field tests, one of them being the German demonstrator.
The German demonstrator, led by innogy and Mitnetz, enables the provision of flexibilities from the high voltage distribution grid to the TSO if support is needed in the transmission grid, but also uses this flexibility to solve congestions in its own (distribution) grid. The aim is to integrate renewable energy resources connected to the high voltage level of the distribution grid into a schedule-based process for congestion management and voltage control in the distribution grid and to support the transmission grid.
The increasing share of renewables, mostly connected to the distribution grid, causes a decrease of connected conventional energy sources (CES), which were mainly connected to the transmission grid. Additionally until today, RES can only be curtailed as a short-term emergency measure to prevent congestion in real-time. RES are so far not part of schedule-based congestion and voltage management processes. For this reason, the flexibility potential in the transmission grid is reaching its limits to solve congestion and voltage issues.
In order to set up the described innovations, the German demonstrator develops tools enabling and enhancing the grid control centre. These tools improve DSO’s grid operation and TSO/DSO coordination; they enable the provision of ancillary services to the TSOs from flexible units connected to the distribution grid, as well as investigating how these flexibilities can meet the needs of both TSOs and DSOs.
The German demonstrator within the broader project has been an outstanding success due to its innovative utilisation of distributed renewable energies as flexibilities for the transmission and distribution grid. It also includes enhanced forecasting of consumption and feed-in from renewables and the schedules provided by generation units for calculating and optimising the power flow in the distribution grid by integrating up-to-the-minute grid data for each 15-minute update.
The project has already succeeded in describing target processes for congestion management and voltage control, in addition to defining the required information exchange with TSOs and the data for the German demonstrator’s platform. It has also laid down a strategy for the implementation of the demonstrator’s platform in terms of the infrastructure of the grid control centre, along with an implementation plan with the grid control centre’s technical supplier.
The required hard- and software components needed for the German demonstrator’s platform have been procured and installed, while proof of concept with the automated reactive power management was achieved using a first use go-live trial.
An overall challenge of the EUSysFlex demonstrator is fulfilling current regulation framework while testing innovative approaches and processes in the real grid environment along with defining internal and external data exchange due to stakeholder requirements and data exchange formats.
As a recent law change in Germany requires a new process to integrate renewable energy resources in the redispatch process for solving congestion in the transmission and distribution grids, the principles designed in the German EU-SysFlex demonstrator are a perfect basis for scaling the approaches and the newly designed process in addition to and using the learnings from the field test to fulfil the requirements of the new law by 2021.
The German demonstrator has proved to be an important piece of the EU’s decarbonisation puzzle as it has generated a high level of knowledge and experience that will offer great insights when it comes to future-proofing TSO-DSO coordination management. Not only will this be valuable when it comes to the implementation of law changes, but it will also assist by creating the necessary flexibilities to ensure smooth and efficient operations across DSOs and TSOs.
1 The EU-SysFlex project is funded under grant agreement No. 773505 from the European Union’s Horizon 2020 research and innovation program.
2 Together with innogy and Mitnetz, Fraunhofer IEE, University of Kassel and INESC TEC are the other three partners involved in the German demonstrator.
3 In Germany the distribution grid reaches from low voltage levels to the 110 kV-level.
4 In Germany more than 90% of the renewable plants are connected to the distribution grid.