EditBattery champion Bulgaria helps neighbours maintain electricity supplies
During the last two years Bulgaria has become the world's No. 1 country by the share of battery energy storage capacity relative to the size of its electricity system
Bulgaria’s rapid expansion of battery storage and renewable electricity has unexpectedly turned the country into a key stabilising force for Southeast Europe’s power system, as Romania and Hungary struggle with the loss of around 2.5 GW of dispatchable generation and soaring evening electricity demand.
The record-low water levels in the Danube and closure of two nuclear power plants in Romania and Hungary is reshaping the debate over the energy transition in the Balkans, with policymakers increasingly pointing to electricity storage, rather than conventional generation alone, as the critical missing link in regional energy security.
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During the last two years Bulgaria has become the world’s No. 1 country by the share of battery energy storage capacity relative to the size of its electricity system, underlining how strategic investment in storage is reshaping power markets across Southeast Europe.
Former Bulgarian environment minister and energy expert Julian Popov argued that Bulgaria’s solar generation, battery storage and Greece’s expanding wind and solar capacity have prevented a wider regional energy crisis.
“Bulgarian solar power, batteries storing just five minutes of lignite generation, together with Greek wind and solar, are saving the region from an energy collapse after Hungary and Romania lost around 2.5 GW of baseload capacity,” Popov said.
He argued that the events demonstrate the need to reassess long-held assumptions about Europe’s electricity systems.
“It is time to start thinking about energy according to the realities of the first quarter of the 21st century,” Popov said.
Energy Minister Iva Petrova said Bulgaria is currently helping neighbouring countries maintain electricity supplies.
“Bulgaria is helping some of the countries in the region in the current situation. The operation of the Kozloduy Nuclear Power Plant is also critical for the functioning of Romania’s energy system at the moment,” Petrova said.
ESO Executive Director Kiril Georgiev said demand from neighbouring countries remains exceptionally strong.
“Requests from Romania are for around 3,500-3,600 MW. Hungary is currently requesting around 4,000-5,000 MW per day. Everything is operating normally for us. We remain more of a net exporter than a net importer,” Georgiev said.
How Bulgaria became the Balkans’ battery champion
The current regional imbalance has highlighted a growing divergence between Bulgaria and Romania.
Romania generates abundant low-cost renewable electricity during daylight hours but has insufficient storage capacity. As a result, it exports electricity to Bulgarian batteries at very low prices before importing electricity back into the system during the evening peak at significantly higher prices.
Bulgaria has followed a different strategy by investing heavily in battery energy storage, allowing it to purchase cheap electricity during the day, store it and sell it back onto regional markets when demand and prices increase.
According to market participants, Bulgaria has now become one of Europe’s leading battery storage markets, with more than 12,000 MWh of installed storage capacity, placing it behind only Germany and Italy, two much larger countries.
Combined with its pumped-storage hydropower facilities, this gives Bulgaria the ability to support its electricity system for around 2.5 hours in the event of a complete blackout, compared with an estimated 15 minutes for Romania.
Romanian opposition MP Claudiu Năsui from the Save Romania Union (USR) said the country’s main weakness is no longer electricity generation but the lack of storage infrastructure.
Energy expert Dumitru Chisăliță told Digi24 that such cross-border trading mechanisms are entirely consistent with the functioning of the integrated European electricity market.
“Bulgaria buys electricity between 10:00 and 18:00 because it has significant storage capacity, then sells electricity in the evening. There is no guarantee it is selling it back to Romania; it could equally be sold to Hungary, Serbia or elsewhere. But yes, this is how the market works,” he said.
Thanks to batteries, solar is now baseload
According to Bulgaria’s Electricity System Operator (ESO), electricity generation has increased by nearly 7% since the beginning of the year, broadly matching growth in domestic consumption, while the country’s export balance remains positive.
Generation from conventional baseload power plants has declined, whereas renewable generation has continued to increase. According to ESO, solar generation currently provides almost half of Bulgaria’s electricity output, while roughly one-third of that production is stored in batteries for sale during higher-priced evening hours.
Solar power plants currently account for the largest share of Bulgaria’s electricity production, ahead of the Kozloduy nuclear power plant, thermal power stations and hydropower facilities.
Electricity demand remains typical for the season and well below the peaks recorded during previous summers.
Bulgaria also remains a net exporter of electricity, supported not only by high domestic generation but increasingly by its battery storage capacity. The country is currently importing cheaper electricity from Greece during daylight hours and exporting electricity to Romania as prices rise later in the day.
Sources: Digi24, Reuters, BNT
Caption: Solar park with battery energy storage near Karlovo, Bulgaria. Facebook
Updated: August 5, 2026 - 06:14
