At the beginning of this summer, in June 2026, EU Member State energy ministers, battery developers and manufacturers, representatives of the renewable energy sector, and financial institutions signed the first EU-level Tripartite Agreement on Energy Storage. The agreement calls on participating Member States to submit concrete national pledges for additional energy-storage deployment during 2026–2028. Its objective is to provide greater visibility on near-term storage development, strengthen the investment case, and accelerate the deployment of flexibility needed to integrate growing volumes of renewable electricity. The pledges are not legally binding, but rather represent political commitments and an indication of the deployment that participating countries expect to achieve. By 2030, the European Commission estimates that around 200 GW of energy-storage capacity will be needed to meet the flexibility needs of the EU energy system, compared with approximately 55 GW installed at the beginning of 2026. According to the Commission, closing this gap will require a combination of technologies, stronger market incentives and faster collective action
Bulgaria has already submitted its national pledge, which is among the more detailed pledges submitted so far, setting out expected additional storage deployment separately for each year. The country expects to add 2.9 GW / 9.7 GWh in 2026, a further 1.15 GW / 4 GWh in 2027, and 290 MW / 1 GWh in 2028. In total, this amounts to approximately 4.34 GW of additional storage power capacity and 14.7 GWh of additional energy capacity over the three-year period. Among the national pledges submitted so far, only Spain has set a higher target than Bulgaria, with approximately 4–5 GW of additional storage power capacity expected over the 2026–2028 period.
| 2026 | 2027 | 2028 | |
| Targets | 2 900 MW 9 700 MWh | 1 150 MW 4 000 MWh | 290 MW 1 000 MWh * (* 432 MW correspond to the restoration of the remaining Chaira units 1 and 4 (2 × 216 MW) |
Importantly, these figures cover energy storage as a whole, rather than BESS alone. Bulgaria’s pledge also refers to the restoration of 432 MW at the Chaira pumped-storage hydropower plant, corresponding to Units 1 and 4, which are currently unavailable. Under the ENTSO-E methodology, restoring these units returns existing but currently unavailable power capacity to the system. It does not, however, create additional usable storage volume in MWh. The additional energy storage volume is expected to be unlocked through the future commissioning of the Yadenitsa project, which would increase the volume of Chaira’s lower reservoir and expand its storage capability.
A pledge that is already being overtaken by the battery market?
Our 2026 dataset puts Bulgaria’s current BESS power capacity at approximately 5.4 GW, ranking third among the EU countries analysed. According to ENTSO-E data, Bulgaria had approximately 1.4 GW of BESS capacity in 2025, which makes the current increase of roughly 4 GW within less than a year. This is already close to the entire additional power capacity envisaged under Bulgaria’s 2026–2028 storage pledge: 4.34 GW.
Bulgaria’s rapid emergence as a battery-storage market has been closely linked to public funding. The RESTORE programme, launched under the Recovery and Resilience Plan (RRP), was designed specifically to establish grid-scale electricity-storage infrastructure and has become one of the main catalysts behind the country’s recent BESS expansion.
The original RESTORE procedure offered grants covering up to 50% of eligible costs, subject to a maximum amount per MWh. Its application window closed in December 2024, after which the programme moved into project selection and implementation. By 2026, ministry communications refer to 81 RESTORE projects under implementation, with a total value of around 603 million EUR and approximately 9.75 GWh of storage capacity.
The second major funding round, RESTORE 2, was introduced as a scaled-up measure under the REPowerEU chapter of Bulgaria’s recovery plan. Support again covers up to 50% of eligible expenditure, capped at 70 000 EUR per MWh of usable storage capacity. The application deadline has already passed in November 2025. The final selection comprises 31 projects with a total project value of 117 million EUR and more than 4 GWh of usable storage capacity. A further 30 proposals worth slightly more than 50 million EUR successfully passed evaluation but were placed on a reserve list because funding was insufficient.
Together, the two RESTORE rounds have selected 112 projects representing approximately 720 million EUR in total project value and more than 13.7 GWh of storage capacity.
| Programme | Projects selected | Total project value | Storage |
| RESTORE 1 | 81 | 603 m EUR | 9.75 GWh |
| RESTORE 2 | 31 | 117 m EUR | >4 GWh |
| Combined | 112 | 720 m EUR | >13.75 GWh |
What happens after RESTORE?
The more interesting question is what will finance the next wave of Bulgarian storage once the major RRP-funded programmes move from selection into implementation.
The EU Modernisation Fund remains an important potential source of financing for Bulgaria: energy storage is explicitly among the types of investment that the Fund can support. However, the Fund operates through national investment proposals and programmes rather than through a single permanent EU-wide BESS application window.
There are also opportunities where storage is linked directly to new renewable generations. For example, the EU’s third renewable-energy financing tender, open until 1 September 2026, includes Bulgaria as a host country and requires supported ground-mounted solar PV projects in Bulgaria to be co-located with battery storage.
Beyond public funding, the long-term investment case for BESS will increasingly depend on its ability to generate revenues from the electricity market. Bulgaria’s growing price volatility, expanding renewable generation and developing balancing markets create opportunities for batteries to combine several revenue streams, including energy arbitrage, balancing and ancillary services. The country’s regional position also matters. Bulgaria is strongly interconnected with neighbouring electricity markets, including Romania and Greece, creating opportunities for batteries to participate in a wider regional balancing environment and to respond to differences in prices and system conditions across interconnected markets.
Moreover, there are already signs that private finance is beginning to play a larger role. In March 2026, a consortium including UniCredit Bulbank, Raiffeisen Bank International, Eurobank Bulgaria, United Bulgarian Bank and the EBRD reported approximately 325 million EUR in project financing arranged for a renewable-energy and storage portfolio developed by Sunotec and Solars Energy. The first stage includes a 171.5 MWp solar PV plant paired with an 89.4 MWh BESS, as well as standalone BESS projects of 200.4 MWh in Vratsa and 190.4 MWh in Miziya. In July 2026, the EBRD approved up to 30 million EUR in senior secured project finance for the development of a 246 MW / 512.5 MWh BESS in south-eastern Bulgaria, co-located with an existing solar plant and a 65 MW / 260 MWh battery system. The total project cost is estimated at 72 million EUR. The EBRD has noted that the absence of long-term revenue-stabilisation mechanisms in Bulgaria has constrained the availability of long-term debt for merchant renewable projects, making its financing particularly important in addressing this market gap.
This points towards a potential gradual shift in the investment model: from projects supported by public grants towards projects that combine public support, private debt and equity, and revenues earned directly in electricity and balancing markets. An interesting conclusion highlighted by Capital Bulgaria is that each euro of grant funding has attracted a further 3 euros from the private sector. According to the publication, public support over the past two years has helped mobilise around 2 billion EUR in private capital, illustrating the potential of public funding to leverage significantly larger volumes of private investment.