Cheap solar and a great wall of EU cash turned the bloc’s poorest member into its battery champion. Its neighbours are left buying power in.
Few countries have witnessed more political upheaval in recent years than Bulgaria, which held no fewer than eight parliamentary elections between 2021 and 2026. Stable government was never really an option, and yet many will argue it hardly mattered: the country has managed to adopt the euro (on January 1, 2026), and (perhaps more importantly) can now boast (thanks to investment in energy storage) one of the most robust energy systems in the European Union. Indeed, no country now stores a larger share of its power.
One of the few ministers with a tenure long enough to make an impact, Zhecho Stankov, Bulgaria’s energy minister since January 2025, opened a battery the size of a small power station at Lovech in the first half of 2026. This 124-megawatt array, built by Renalfa, could hold 496 megawatt-hours and was for a while the largest such installation in the European Union. Stankov called it a “first step” towards 10 gigawatt-hours of storage. It also makes Bulgaria a part of the energy supply chain, enhancing its regional influence.
The local grid operator, ESO, counted 3,432 megawatts of storage on the system by May 2026; by mid-June the trade weekly Capital put the figure nearer 4,800 megawatts and 14 gigawatt-hours. Just two years earlier, Bulgaria had an almost inconsequential 200 megawatt-hours installed.
Stankov’s ministry announced the move towards storage in April 2025, shortly after he took over the portfolio. The plan was ambitious, comprising 82 projects, 9.7 gigawatt-hours and 588 million euros of European Recovery money, under a scheme called RESTORE that had launched the previous August. The regulator, the Energy and Water Regulatory Commission, had tightened rules in September 2024, demanding financial guarantees to see off speculators, after amendments to the Energy Act that year let a battery trade on the market in its own right. A second round closed in December 2025 with 31 more projects and over four gigawatt-hours. Developers put in far more than the state did, with private money roughly doubling the public grant.
The state utility NEK joined in too. In February 2025 it said it would add nearly 300 megawatt-hours of batteries at five of its hydropower sites. Under the recovery plan, roughly 1.18 gigawatts of solar paired with storage had to be running by March 2026, which pushed developers to bolt panels and cells together rather than build either alone. By the start of 2025, one market survey reckoned, a standalone solar park in Bulgaria was no longer worth financing without a battery beside it.
Martin Georgiev of Electrohold, a utility, reckons more than one terawatt-hour of solar power was thrown away in 2025, close to three per cent of what Bulgaria consumed, because there was nowhere to put it. Installed solar had passed 6.5 gigawatts by early 2026, over half the country’s generating capacity. Midday prices now sink below zero and climb back to 250 euros a megawatt-hour by evening. Nikola Gazdov, who chairs APSTE, a storage association, traced the battery rush in April 2026 to exactly this, namely the cheap solar that pays best only if someone can hold it until it is needed.
The old machines
Chaira, an 864-megawatt pumped-storage plant in the Rila mountains, has sat idle since April 2022, when a turbine in its fourth unit failed, and a full repair is not expected before mid-2027. For decades that plant was indicative of how Bulgaria stored power, but the batteries are now filling the gap it left. Behind them run the Kozloduy nuclear station, whose two reactors supplied about 35 per cent of electricity in 2024 and switched to Westinghouse fuel from May 2024, and the Maritsa East lignite complex, the largest coal-mining site in south-east Europe. Bulgaria was a net exporter of power last year, though only just: net sales fell to 1,268 gigawatt-hours in 2024, six times below the level of 2022. This year’s export figures are likely to be much higher.
Gabriel Avăcăriței, who edits the trade site Energynomics, worked out from Transelectrica’s data that Romania was a net importer for roughly 72 per cent of 2025. Balázs Markó, a researcher at RoEM-UBB in Cluj, put the gap at about five billion euros of energy bought over sold that year; “Accelerating the transition to renewable energy sources can represent a solution for both challenges,” he argues. Romania had once itself been an exporter, and only switched to importing after 2019; its first 500 megawatts of storage arrived in 2025. Hungary bought in more still, running an 18 per cent net-import share and leaning on Slovakia for nearly two-thirds of it. Poland, for its part, still drew 57 per cent of its power from coal.
Evangelos Gazis of Aurora Energy Research, a consultancy, told Capital in July that “batteries are starting to change the way the power system behaves.” His firm expects solar’s capture price to run about 48 per cent below baseload from 2030, as the panels cannibalise one another, which is precisely what makes a battery worth building (something that Bulgaria, uniquely in the region, appears to recognise). Aurora reckons Bulgaria has already contracted more than 14 gigawatt-hours, against a 2030 target of 1.28 gigawatts, four years early. It’s not all good news, however. Interconnectors are congested and arbitrage margins are thinning, and much of the boom has been based on subsidies that will not last forever.
Nevertheless, Bulgaria’s quick action has largely insulated it from the problems facing other countries in the region, notably Romania, where a failure to invest in storage has forced it to appeal to the population to save energy at peak times. In the short-term, the country has had to resort to sinking barges in the Danube to boost the river’s depth in order to keep its nuclear power plant running. Longer-term, it wants to re-open closed coal-fired power plants, risking EU opprobrium and placing the status of funding for its energy transition in jeopardy. Bulgaria, meanwhile, has no such concerns.
Photo: Dreamstime.