Good news for the grid from the Osmose tests

New scenarios and challenges for energy transition were the focus of the workshop Research and the role of Flexibility for the Electricity System: the OSMOSE Project, hosted by Terna on 15 September in its Rome auditorium and streamed on the web. The day was dedicated to the most significant topics and results from the OSMOSE Project, conducted as part of the European Horizon 2020 programme thanks to an investment of over €27 million.

The purpose of the testing was to tackle the management difficulties and the discontinuity of renewable energy sources by studying methodologies and instruments to increase their usability for the grid as much as possible. In order to integrate the production of renewables, it is necessary to increase the flexibility of the grid and the electricity system. This is reflected in the project acronym OSMOSE (“Optimal System Mix of Flexibility Solutions for European Electricity”), which sees the Italian national transmission grid operator at the forefront for Italy, along with research centres, universities and businesses. The convention opened with an address from Luca Marchisio, System Strategy Manager at Terna, on the role of flexibility for the electricity system and the challenges to be faced by 2050, including the security, resilience, planning and stability of the system itself.

In fact Osmose investigated various sources of flexibility in order to identify the “perfect” mix, both in theory and in practice, through complex tests or “demonstrations”. Coordination of the Italian demonstration was handled by energy engineer Leonardo Petrocchi, who illustrated the need to demonstrate a number of flexibility solutions through a series of technological developments in real test environments, on portions of the grid affected by significant penetration of renewable energy and related management problems.

Through the Italian demonstration, further analysis was conducted on the technical-economic feasibility of solutions like grid management at given temperatures through innovative Dynamic Thermal Rating (DTR) techniques; congestion resolution and voltage regulation by modifying the loads of certain industrial systems; and the supply of synthetic inertia and voltage regulation by wind power plants, with and without integrated electrochemical storage.

On a practical level, 18 DTR devices were installed between the power lines and substations of Apulia and Basilicata, while upgrades were made to the control systems of wind power plants and five industrial systems, as well as the installation of the Zonal-Energy management system (Z-EMS).

The former (DTR) are innovative sensors that measure the temperature conditions of the overhead power lines to verify their effective transport limit; the EMS, on the other hand, is a smart grid management tool that aims to anticipate and resolve grid congestion using the information processed by the DTR, allowing the possibility of adjusting the load for industrial users. The purpose of the Z-EMS is to optimise costs and, therefore, to take advantage of new flexibility resources to prevent the need to rely on conventional generation.

The solutions were tested for eight months through the local and remote monitoring of all systems involved, with the continuous operation of the DTR and Z-EMS systems developed on Terna assets: a portion of the grid between Apulia and Basilicata, consisting of 7 lines at 150 kV, affected by congestion and the need to regulate voltage.

At the end of this stage, the tests confirmed that a smart management system, paired with “capital-light” technologies, allows the flexibility of existing assets to be fully exploited. The wind power plants met expectations of their capacity to support voltage regulation, demonstrating their potential for supplying this service. In relation to the medium-term supply of synthetic inertia, the technical solutions tested also showed promising results in terms of flexibility, response times and event detection.