Bulgaria’s transmission system operator ESO has invested more than 182 million euros in modernising the country’s electricity transmission network since the start of 2026, the operator reported. The work includes construction and reconstruction of more than 120 kilometres of transmission lines.
The spending extends a programme aimed at improving supply reliability, reinforcing substations and preparing the grid for additional electricity generation and new connections. It includes upgrades to overhead infrastructure and substation equipment in several parts of Bulgaria, targeting the resilience of existing assets and capacity for future projects.
Substation equipment improvements are intended to strengthen system operations and enable electricity supply to be restored more rapidly after network incidents. The measures are particularly relevant in autumn and winter, when storms and adverse weather can damage lines and interrupt service.
Bulgaria’s power system has a key position in Southeastern Europe’s regional electricity market, linking neighbouring countries with significant differences in generation mix and demand. Reliable transmission supports domestic security of supply and commercial electricity exchanges across borders.
Grid reinforcement also enables new solar, wind and other generation assets to connect. Demand for connections can rise faster than transmission capacity, making equipment availability, substations and operational flexibility important factors in project schedules.
The programme shows that investment in generation alone does not resolve energy-system constraints. Its longer-term impact will be measured by improved reliability, effective use of existing grid assets and the ability to bring additional projects into operation without creating new bottlenecks.
