Bulgaria’s €104/MWh day-ahead average was almost €20/MWh below Hungary’s level, although its fifteen-minute evening peak still approached €199/MWh. The country’s diversified generation mix allows it to absorb increasing solar output while remaining less dependent on imports during the evening hours.
Electricity production reached approximately 26.9 TWh between 1 January and 9 August, representing a 7.8% increase year on year. Consumption also rose, increasing by 6.8% to around 25.0 TWh, leaving Bulgaria with a cumulative electricity surplus of approximately 1.86 TWh.
Hydropower generation increased significantly to around 3.4 TWh, compared with 1.81 TWh during the same period in 2025. Transmission-connected renewable generation also increased by more than 16%, reaching approximately 2.94 TWh.
Despite the country’s growing generation surplus, the price curve shows that hourly scarcity remains a significant market feature. IBEX prices fell to just €11/MWh during the strongest solar-production period before climbing to almost €199/MWh during the evening ramp.
This widening intraday spread is creating an increasingly attractive market for battery energy storage. Sunotec’s two operating storage systems at Brusartsi and Byala Slatina have a combined capacity of 200 MW/505 MWh, with market access and optimisation provided by Slovenian trader GEN-I.
The systems can discharge at high power for approximately two and a half hours, allowing them to target the most expensive part of the evening ramp. GEN-I’s planned expansion across another nine Bulgarian projects, totalling 195 MW/782 MWh, would increase average storage duration towards four hours and provide greater coverage during longer periods of scarcity.
Bulgaria’s rapid solar expansion is therefore creating two increasingly distinct electricity markets. Solar developers are competing to sell power into increasingly depressed midday prices, while batteries and flexible thermal generators are competing to capture value from the evening recovery.
For new photovoltaic projects, the implication is increasingly clear: without storage, flexible offtake arrangements or a carefully structured PPA, captured solar prices may fall materially below the IBEX baseload average. The country’s annual generation surplus does not remove this risk; instead, it is reshaping when electricity has value.
