Bulgaria has significantly expanded its energy storage capacity following the completion of a major battery deployment by renewable developer Sunterra RE, which has finished the second phase of its storage expansion program. The project adds a combined capacity of nearly 397 MW and 1.3 GWh across three new facilities.
The newly commissioned battery systems are located in the municipalities of Galabovo, Kaloyanovo, and Karlovo. Together, they substantially enhance the company’s ability to store surplus electricity generated from renewable sources and discharge it back into the grid during periods of higher demand, improving overall system flexibility.
Before becoming operational, all three installations received full approvals from the relevant regulatory authorities, confirming compliance with technical, safety, and market operating standards. This clearance allows the facilities to participate fully in electricity market operations.
The projects were fully financed through Sunterra RE’s own capital, reflecting a strong long-term commitment to the development of battery energy storage infrastructure in Bulgaria. The installations use lithium iron phosphate (LFP) technology, widely adopted in large-scale storage systems due to its stability, durability, and high operational reliability. Each system is designed to store energy for up to four hours, with efficiency rates of around 90%, and an expected operational lifespan of approximately 25 years.
The two largest facilities are located in Galabovo and Kaloyanovo, each offering 150 MW of installed capacity. The Galabovo site provides 450 MWh of storage, while Kaloyanovo reaches 506 MWh. The third site in Karlovo adds an additional 97 MW and 320 MWh of capacity.
By storing excess renewable generation and releasing it during peak consumption periods, the new systems are expected to strengthen grid balancing capabilities and reduce pressure on Bulgaria’s electricity network. The company says the projects will enhance market flexibility and support the integration of higher volumes of renewable energy into the national power system.
