Session duration: 30-45 min + 15 min round-table discussion
In recent years, Slovenian and Croatian electricity systems have been increasingly challenged by four contradictory influences: increasing support of renewable energy sources (RES) integration, lower electricity consumption due to the economic crisis, a growing lack of centralized electricity production for electric system support as well as high interconnectivity between the neighboring control zones. Consequently, the Slovenian and Croatian transmission systems are facing overvoltage issues as well as a decrease in secondary reserve capacities. This also affects the security of supply at European level because of the major transit flows hosted by the two countries.
The Slovenian and Croatian TSOs and DSOs started separately addressing these issues in 2014. Classical engineering approaches to address them were taken into account in the two existing TYNDPs. They studied first the implementation of technical measures within each control zone, but soon came to the conclusion that:
- Uncoordinated actions taken in one of the two control zones would significantly impact the other since these two control zones are highly interconnected;
- A progressive deployment of technological solutions would be less efficient since the same issues would resurface soon, leading to repeated investments in order to keep the security of operation above the bottom line;
- In the long-run, uncoordinated approach would never lead to a satisfactory level of security of operation while allowing for hosting higher levels of RES integration and maintaining a sufficient level of ancillary services in both electricity systems.
Therefore joint actions would create synergies and solve the problem in a sustainable way.
The TSOs and DSOs therefore agreed to work together to address all the pending issues and designed a joint cross-border systemic approach to bring enduring solutions to all of the four above issues at once.
They end up with the smart grid PCI SINCRO.GRID investment project: it is an innovative system integration of several mature technology components where synergies among all the proposed solutions are searched to maximize the investment impact onto both electric systems and create further regional benefits.
The main components of the SINCRO.GRID project are:
- The deployment of compensation devices to address overvoltage and voltage instability issues within the transmission grid.
- The deployment of advanced dynamic thermal rating (DTR) systems in both the Slovenian and Croatian transmission grid
- The integration of distributed renewable generation (DG) in secondary regulation in Slovenia and voltage regulation in Croatia.
- The implementation of a virtual cross-border control centre (VCBCC) which consists of dedicated IT infrastructure and software to be used by system operators for the efficient and coordinated management of RES.
- The deployment of electricity storage systems (batteries) with a capacity of 10 MW in Slovenia.
The SINCRO.GRID project integrates new active elements in the transmission and distribution grids, managed via a virtual cross-border control centre involving advanced data management, common system optimization and generation/consumption forecasting, thanks to increased cross-border cooperation between TSOs and DSOs. A key aspect of the SINCRO.GRID project lies in the synergy brought by the simultaneous deployment of a portfolio of mature technology-based solutions: jointly, they bring high benefits and positive externalities.
The investment value of the SINCRO.GRID project amounts to 88.6 million Euro, and at the end of February 2017, financing was approved by Connecting Europe Facility – CEF fund (European commission) in the amount of 40.5 million Euro, i.e. 51% of the eligible costs since the submission of the application.