Bulgaria’s electricity landscape has undergone a significant transformation, marking a pivotal moment in 2025 when renewable energy sources emerged as the second-largest contributor to the country’s electricity production, following nuclear power. This shift is underscored by the combined output from solar, wind, hydropower, biomass, and waste, which has now outstripped that of coal-fired plants. This development signals a concrete advancement in Bulgaria’s energy transition.
According to data from the Electricity System Operator (ESO), this transition was primarily driven by the rapid growth of solar capacity and the increasing importance of battery storage technologies. These advancements have allowed for extended usable hours of photovoltaic energy generation. In contrast, coal-based electricity generation has seen a marked decline, reaching its lowest levels ever recorded in Bulgaria.
While Bulgaria continues to be a net exporter of electricity, the scale of net exports has diminished significantly, totaling 1,268 GWh—nearly six times lower than the robust export levels witnessed in 2022. This change reflects a notable shift in the regional energy dynamics. Coal output has plummeted since 2023, with 2025 figures indicating a reduction of approximately 60% compared to 2022. This drop exceeds targets set forth in the Recovery and Resilience Plan, which aimed for a 40% reduction from 2019 levels; actual reductions have now reached nearly 49%.
The pressure on coal-fired power plants is expected to escalate further in 2026 when the contract for the AES Galabovo plant expires. The rising prices of carbon allowances, currently around €85 per ton, have diminished the competitiveness of coal generators. Consequently, TPP Maritsa East 2, Bulgaria’s state-owned coal plant, is increasingly focusing on supplying regulated household consumption through a newly established exchange-based purchasing model, even while operating at a loss. Despite these challenges, coal is anticipated to remain Bulgaria’s third-largest source of electricity for several years due to the limited role of natural gas in the power sector.
In stark contrast to coal’s decline, solar power has entered an aggressive expansion phase. Approximately two-thirds of Bulgaria’s over 4.5 GW installed solar capacity was added within the last three years. Enhanced panel efficiency and improved battery systems have resulted in a quadrupling of solar output compared to 2022 levels. By 2025, solar energy was generating about two-thirds of what coal-fired plants produced; if current trends persist, it could exceed 80% of coal generation as early as 2026. This year is also projected to witness record installations of battery storage systems that will help manage solar electricity production and mitigate price fluctuations.
However, wind energy development faces hurdles due to prolonged administrative and environmental approval processes that can take three to five years. This delay is critical since wind generation typically peaks at night and during winter months, complementing solar production patterns. The introduction of new wind farms with capacities ranging from 70 to 100 MW is not anticipated until late 2027.
Bulgaria’s regional role within the energy market is evolving as well. Instead of primarily serving as an exporter, Bulgaria is increasingly positioned as a balancing hub within Southeast Europe. Data from ENTSO-E indicates that Bulgaria has become a consistent net importer of electricity from neighboring Greece and Turkey, where progress in renewable energy adoption has been more rapid. Greece has notably accelerated its renewable initiatives while reducing reliance on coal through increased gas usage.
Looking forward, Bulgaria stands to become a crucial flexibility provider in Southeastern Europe. With ongoing expansions in battery storage capabilities and planned new pumped-storage hydropower projects, Bulgaria has the potential to serve as a large-scale energy buffer. This emerging role could yield both commercial benefits and strategic advantages as the region navigates its evolving energy landscape.
