Bulgaria increased electricity production by 6.84 per cent during the period from 1 January to 2 August 2026, even as output from its traditional coal and nuclear baseload fleet declined.
Data from transmission system operator ESO show that national generation reached 25.95 TWh, while electricity consumption increased by 6.55 per cent to 24.29 TWh. The difference left Bulgaria with net electricity exports of approximately 1.66 TWh.
The most important structural change occurred within the generation mix. Baseload plants, defined principally as coal and nuclear facilities, produced 16.27 TWh, a year-on-year decline of 13.4 per cent. Total production nevertheless increased because renewable generation and other sources compensated for part of that contraction.
Renewable electricity connected to the transmission network rose by 13.44 per cent to 2,773.3 GWh. Renewable production in the distribution system increased by 5.08 per cent to 2,598.2 GWh. Combined transmission- and distribution-connected renewable generation therefore exceeded 5.37 TWh.
Bulgaria’s electricity balance remains supported by the two operating units at Kozloduy nuclear power plant, which supplied close to 1,890 MW on average at the beginning of August. Nuclear output was complemented by coal generation of around 900 MW, solar output of approximately 1,349 MW and smaller contributions from hydro, gas and wind.
The country was exporting an average 1,425 MW on 4 August, including substantial flows towards Romania and Serbia. Bulgaria supplied approximately 1,536 MW to Romania and 366 MW to Serbia, while importing electricity from Greece during parts of the day.
That position gives Bulgaria an increasingly important balancing role in the eastern SEE market. Romania is managing nuclear and hydrological constraints, while Serbia is contending with weak hydro production and growing summer demand. Bulgarian exports are helping cover both markets while supporting transfers further north towards Hungary.
The decline in baseload generation remains commercially significant. Higher renewable output can lift annual energy production, but it cannot replicate the hourly availability of coal and nuclear generation without storage, flexible demand or additional cross-border capacity. Bulgaria’s export strength during the summer therefore depends on the continued availability of Kozloduy, the operating condition of its coal fleet and the timing of solar production.
