Bulgaria has expanded its energy storage capacity after renewable developer Sunterra RE completed the second phase of its battery deployment programme. The new build adds nearly 397 MW of combined capacity and about 1.3 GWh across three facilities.
New battery sites in Galabovo, Kaloyanovo and Karlovo
The newly commissioned battery systems are installed in the municipalities of Galabovo, Kaloyanovo, and Karlovo. The facilities are designed to store surplus electricity produced from renewable sources and discharge it back to the grid during higher-demand periods. Together, they are intended to improve overall system flexibility.
Prior to entering operation, all three installations obtained full approvals from the relevant regulatory authorities. The approvals confirm compliance with technical, safety, and market operating standards. With this clearance in place, the facilities can participate fully in electricity market operations.
Financing, technology and performance parameters
The projects were financed entirely through Sunterra RE’s own capital. The installations use lithium iron phosphate (LFP) technology for energy storage. Each system is designed for up to four hours of storage duration, with efficiency around 90% and an expected operational lifespan of approximately 25 years.
Facility capacities: 150 MW units and a Karlovo addition
The two largest facilities are located in Galabovo and Kaloyanovo, each with installed capacity of 150 MW. The Galabovo site provides 450 MWh of storage, while Kaloyanovo reaches 506 MWh.
The third facility is in Karlovo, adding an additional 97 MW and 320 MWh. By shifting stored power to periods of peak consumption, the new systems are expected to support grid balancing and reduce pressure on Bulgaria’s electricity network.
Sunterra RE states that the deployments will enhance market flexibility and support integration of higher volumes of renewable energy into the national power system.
