Bulgaria’s net electricity exports increased 62% to 3.5 TWh in the first nine months and opening days of October 2026. The rise was linked to expanding renewable generation and battery storage, supporting Bulgaria’s role as a supplier to Southeast Europe. Net exports were 2.16 TWh during the comparable period of 2025, based on transmission operator data presented by the Association for Production, Storage and Trading of Electricity.
Total electricity generation grew 12.24%, while domestic consumption increased 8.45%. Renewable generation reached approximately 11.5 TWh, nearly 34% higher year on year. Renewables accounted for nearly 80% of the increase in national electricity production, reflecting a shift in Bulgaria’s generation mix.
Solar output and batteries support more flexible export timing
Solar power contributed to additional electricity, while battery systems enabled production to be moved from low-price daytime periods into more valuable evening hours. Battery systems reportedly delivered approximately 1.72 TWh to the Bulgarian electricity system between January and early October. This compared with around 190 GWh a year earlier.
The reported increase reflects rapid expansion of installed storage and its growing function in wholesale-market optimisation. On October 8, Bulgarian solar generation approached 4.3 GW during the early afternoon, exceeding domestic consumption of around 4.1 GW. Battery charging absorbed a substantial part of that surplus, allowing electricity to be retained for later delivery.
The change affects how renewable output is valued commercially, particularly during periods when solar generation exceeds demand. Without storage, additional solar capacity can deepen midday price declines and increase curtailment. With batteries, part of that production can be shifted into hours when Romania, Hungary and other neighbouring markets face stronger demand and higher prices.
Nuclear maintenance and river conditions affect firm generation availability
Bulgaria’s renewable and storage growth is relevant because its nuclear fleet has faced operational constraints. Kozloduy unit 6 entered scheduled maintenance in October, while unit 5 was exposed to low Danube water levels. Together, these factors reduced available firm generation and increased the importance of solar, batteries and other dispatchable resources.
Bulgaria also faces a seasonal challenge as solar output declines during winter while electricity demand rises. The next investment requirement is therefore expected to include additional wind, longer-duration storage and transmission capacity able to move electricity toward regional scarcity markets.