Background: Bulgaria becomes a regional energy storage hub
Bulgaria’s abundant energy storage capacity is making it a regional energy hub. Even if domestic power generation exceeds demand, the country can import electricity at low, zero, or even negative prices, and then export it when the electricity price rises in the evening.
Currently, the total installed capacity of battery systems in Bulgaria exceeds 2 GW, and the storage capacity is nearly 8 GWh, which is sufficient to supply power to the entire country for two hours.
The formation of this pattern was mainly facilitated by the policy-driven efforts of the European Union (EU) through the RESTORE support program, as well as the government’s strategic layout for large-scale pumped storage hydropower.
Market status: The fastest-growing energy storage market in Europe
The expansion rate of the battery storage market in Bulgaria is far ahead of that of any other country in Europe, considering both the economic size and population.
The installed capacity of the battery energy storage system (BESS) is expected to reach 3.5 GW by the end of the year.
The neighboring country Greece is lagging significantly and is not expected to reach 1 GW until 2026.
Subsequently, as the daily price gap narrows, the growth rate of the Bulgarian energy storage market is likely to slow down.
The core driving force behind this market is solar power generation. Without energy storage, solar investment would face an extremely high risk of losses. This also makes the business logic of battery energy storage systems (BESS) particularly clear.
Case: The actual situation of arbitrage on April 29th
According to the data from the Electricity System Operator (ESO), at 15:55 on April 29th:
The energy storage system not only absorbed all the surplus electricity, but also imported additional power from neighboring countries. During the 15-minute period ending at 16:00:
The current market electricity price in Bulgaria: 44.34 euros per MWh
The current market electricity price in Greece: 0.01 euros per MWh
Plan to flow from Greece to Bulgaria: 879 MW
The price difference was 44.33 euros per megawatt-hour. Some of the stored electricity was later returned to Greece, while more was sent to Romania.
Battery energy storage is gradually evolving into a major flexible electricity user, and is reshaping the power market landscape in the Balkans region.
Extreme situation: Negative electricity price set new record on May 1st
During the sunny and warm holidays in spring, the demand for heating and cooling is low, and the electricity price fluctuations are particularly intense. Hungary, Greece, Bulgaria and Romania consistently rank among the top ten countries in the world with the highest daily share of photovoltaic power generation.
On May 1st, electricity prices in several European countries plummeted, setting several new records:
Day-ahead market
In most parts of Europe, electricity prices are approaching the price floor of -500 euros per megawatt-hour.
Germany (Germany) report -499.99 euros/MWh, with a price difference of over 700 euros/MWh compared to the evening peak price.
The Hungarian Electricity Exchange (HUPX) reached the limit-down price and remained there for a duration of 2.5 hours.
Intraday market
Electricity price drops to historical low: **-855.24 euros/MWh** (as reported by Montel)
The day’s price difference was close to 1,100 euros/MWh.
The lower limit of the price allowed in the domestic market is -9,999 euros per megawatt-hour.
Conclusion
The prerequisite for generating profits from charging is that the price difference must be higher than the operating costs of the energy storage facilities. Currently, this condition still holds true, and the profit potential is significantly greater in extreme market conditions. As the penetration rate of renewable energy in Europe continues to rise, the window for energy storage arbitrage will become more frequent, and Bulgaria’s leading position may be further consolidated.