Bulgaria’s €104/MWh day-ahead average was almost €20/MWh below Hungary, although its fifteen-minute evening peak still approached €199/MWh. The country’s wider generation portfolio allows it to absorb more solar without becoming as dependent on imports after sunset.
Electricity production reached approximately 26.9 TWh between 1 January and 9 August, up 7.8 per cent year on year. Consumption rose by 6.8 per cent to about 25.0 TWh, leaving a cumulative surplus of 1.86 TWh.
Hydropower generation increased to approximately 3.4 TWh, compared with 1.81 TWh in the corresponding 2025 period. Transmission-connected renewable output rose more than 16 per cent to around 2.94 TWh.
The price curve nevertheless demonstrates that Bulgaria’s accumulated generation surplus does not eliminate hourly scarcity. IBEX declined to €11/MWh during the solar period before increasing to almost €199/MWh in the evening.
This is precisely the spread targeted by the Bulgarian battery fleet. Sunotec’s two operating storage systems at Brusartsi and Byala Slatina provide combined capacity of 200 MW/505 MWh, with market access and optimisation handled by Slovenian trader GEN-I.
The batteries can discharge at high power for approximately two and a half hours, matching the most expensive part of the evening ramp. GEN-I’s planned expansion across another nine Bulgarian projects—195 MW/782 MWh—would increase average duration towards four hours and provide greater protection against extended scarcity.
Bulgaria’s solar expansion is consequently creating two separate markets. Solar developers compete to sell into increasingly weak midday prices, while batteries and flexible thermal generators compete to monetise the evening recovery. New photovoltaic projects without storage or a carefully structured PPA will face materially lower captured prices than the IBEX baseload average.
