Bulgaria’s transmission system operator ESO has invested more than €182 million in modernising the country’s electricity transmission network since the start of 2026, according to the operator. The spending extends a programme aimed at improving supply reliability and preparing the grid for additional generation and connections.
The work includes construction and reconstruction of more than 120 kilometres of transmission lines, along with upgrades to overhead infrastructure and substation equipment in several parts of Bulgaria. ESO is targeting the resilience of existing assets and the network’s capacity to accommodate future projects.
Substation improvements are intended to make system operations more robust and allow electricity supply to be restored more quickly after network incidents. The measures are especially relevant in autumn and winter, when storms and adverse weather can damage lines and interrupt service.
Bulgaria’s power system links neighbouring countries with significant differences in generation mix and demand. Reliable transmission supports domestic security of supply as well as commercial electricity exchanges across borders.
Reinforcing the network can enable connections for new solar, wind and other generation assets. But connection demand can rise faster than transmission capacity, leaving equipment availability, substations and operational flexibility as important factors in project schedules. Investment in generation alone does not resolve those system constraints.
The programme’s longer-term impact will be measured by reliability, effective use of existing grid assets and the ability to bring additional projects into operation without creating new bottlenecks.
