Bulgaria’s NEK deploying BESS at hydropower plants

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State-owned utility and power generation firm NEK is deploying BESS at its hydropower plants across Bulgaria.

The National Electricity Company (NEK) is moving to upgrade five hydropower plants with battery energy storage system (BESS) technology according to local reports, partially confirmed by announcements on NEK’s website.

The company aims to add a 10MWh BESS unit to its new Vacha 1 hydropower plant by the end of 2025 and has launched a call to do the same at four others. Those four have a total expense cited by reports of €63.2 million (US$65 million).

On 20 January, NEK announced four separate notification of investment intentions for energy storage systems, in the towns of Boynik, Aleko Konstantinov, Muhovo and Devin in the Kardzhali, Pazardzhik, Sofia and Smolyan regions respectively. Those locations are in the south and west of Bulgaria.

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The announcements didn’t give more information than that, but local reports said the four additional BESS units will total ‘at least’ 279MWh.

The reports indicate the hydropower plants are run-of-river, while NEK also has substantial pumped hydro energy storage (PHES) plants both operating and in construction across Bulgaria.

The BESS will help to optimise the production of the five hydropower plants, and will be deployed with configurations of between two and three hours and capable of at least 6,000 cycles. The four additional hydropower plants to have co-located BESS are Studen Kladenets, Aleko, Devin and Topolnitsa, the reports add.

Bulgaria was in the headlines late last year after a 3GWh standalone energy storage tender, funded by the EU’s Recovery and Resilience programme, was oversubscribed by a factor of four.

The largest grid-scale BESS projects online that Energy-Storage.news has reported on are a 55MWh project by independent power producer (IPP) Renalfa and a 17.8MWh commissioned by China-based energy storage technology firm Sermatec for an unnamed owner.

6 October 2026
Warsaw, Poland
The Energy Storage Summit Central Eastern Europe is set to return in September 2025 for its third edition, focusing on regional markets and the unique opportunities they present. This event will bring together key stakeholders from across the region to explore the latest trends in energy storage, with a focus on the increasing integration of energy storage into regional grids, evolving government policies, and the growing need for energy security.
19 November 2026
London, UK
The Energy Storage Awards (ESAs) aim to reward excellence and hard work in the European industry, recognising the pioneering spirit and dedication to positive change it represents. Now in their fourth year, the Energy Storage Awards are brought to you by Solar Media, publisher of global energy storage industry website Energy-Storage-News, and host of events including the Energy Storage Summit series in the UK, US, Asia and Australia.
2 December 2026
Italy
Battery Asset Management Summit Europe is the annual meeting for owners, operators, investors, and optimisation specialists working with operational BESS assets across the continent. The Summit focuses on how to maximise performance and revenue, manage degradation, integrate advanced optimisation software, navigate evolving market and regulatory frameworks, and plan for repowering or end-of-life strategies. With insights from Europe’s most active storage markets, it equips attendees with practical guidance to run resilient, profitable battery portfolios as the sector scales.

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