ESO to Receive 50% European Grant Co-financing of the Over EUR 59 Million Investment in Bulgaria’s Electricity Grid Under the CARMEN Project
EUR 29 million in grants from the Connecting Europe Facility have been provided for the implementation of investments by the Electricity System Operator in Bulgaria’s electricity grid under the joint project CARMEN: Romanian and Bulgarian Smart Grid Assets Increasing RES and Interconnection within South-East Europe. Investments of more than EUR 59 million will be made on Bulgarian territory, of which 50% grant European funding.
The project CARMEN: Romanian and Bulgarian Smart Grid Assets Increasing RES and Interconnection within South-East Europe is implemented by the Electricity System Operator of Bulgaria, the Distribution System Operator of Romania – Delgaz and the Romanian Transmission System Operator Transelectrica. The total budget of the project is nearly EUR 208 million, of which 50 per cent shall be grant funds.
The grant agreement was signed on 22 May 2026 in Copenhagen, the capital of Denmark, at an official ceremony within the annual Energy Infrastructure Forum chaired by EU Commissioner for Energy and Housing, Mr Dan Jørgensen.
The project envisages the reconstruction, expansion and introduction of automated control systems in the Dobrudzha, Varna, Gorna Oryahovitsa, Mizia and Balkan substations by the end of 2032, the installation of passive optical rings for telecommunication network of overhead lines with a total length of over 1100 km in total, including two of the interconnectors with Romania – OHLs 400 kV Druzhba and 400 kV Saedinenie, as well as the installation of active optical rings for telecommunication network at all substations managed by ESO.
The implementation of the investments under the project on Bulgarian territory aims at modernizing the electricity transmission network and increasing its capacity in Northeastern Bulgaria to exploit the potential for green electricity production, deploying green hydrogen production technologies and ensuring the transmission of renewable electricity along the priority North-South corridor.
The CARMEN: Romanian and Bulgarian Smart Grid Assets Increasing RES and Interconnection within South-East Europe is part of the CARMEN Project of Common Interest, which at the end of 2025 was included in the second list of the European Commission of priority European projects for the development of trans-European energy infrastructure.