Bulgaria increased electricity production by 6.84% between 1 January and 2 August 2026, while output from its traditional coal and nuclear baseload fleet declined. Data from transmission system operator ESO show national generation reached 25.95 TWh. Electricity consumption rose by 6.55% to 24.29 TWh. The resulting gap left Bulgaria with net electricity exports of approximately 1.66 TWh.
Shift in generation mix
The largest change in the period was within the generation structure. Baseload plants, defined principally as coal and nuclear facilities, produced 16.27 TWh, down 13.4% year on year. Total production still increased as renewable generation and other sources offset part of the baseload contraction.
Renewable electricity connected to the transmission network increased by 13.44% to 2,773.3 GWh. Renewable output in the distribution system rose by 5.08% to 2,598.2 GWh. Combined transmission- and distribution-connected renewables therefore exceeded 5.37 TWh.
Kozloduy nuclear and thermal support
Bulgaria’s power balance is supported by the two operating units at the Kozloduy nuclear power plant, which supplied close to 1,890 MW on average at the beginning of August. Nuclear generation was complemented by coal output of around 900 MW. Solar production averaged approximately 1,349 MW, with smaller contributions from hydro, gas and wind.
The availability of these dispatchable sources remains relevant for meeting demand patterns during summer operations . Higher renewable output can increase annual energy totals, but it does not provide the same hourly availability as coal and nuclear without storage, flexible demand or additional cross-border capacity . Export performance during the summer therefore depends on Kozloduy availability, the operating condition of the coal fleet and the timing of solar generation.
Cross-border flows in eastern SEE market
Bulgaria exported an average of 1,425 MW on 4 August, including substantial flows towards Romania and Serbia. It supplied approximately 1,536 MW to Romania and 366 MW to Serbia. During parts of the day, Bulgaria imported electricity from Greece.
This export pattern supports Bulgaria’s balancing role in the eastern SEE market . Romania is managing nuclear and hydrological constraints, while Serbia faces weak hydro production alongside growing summer demand. Bulgarian exports help cover both markets while supporting transfers further north towards Hungary.
