Enery completes 150 MW battery storage commissioning near Nova Zagora to strengthen Bulgaria’s grid

Enery has completed commissioning of a large-scale battery energy storage system in southeastern Bulgaria, adding one of the biggest operational storage facilities in Central and Eastern Europe. The start-up of the Nova Zagora project matters for investors and grid operators because it targets two pressures that often rise together as power systems add more renewables: managing variability while maintaining reliability during peak demand.

150 MW standalone facility built for peak balancing

The standalone installation is located near Nova Zagora and has a total storage capacity of 601.8 MWh with an installed power output of 150 MW. Its operating concept is straightforward: it absorbs excess electricity during low-demand periods and releases it back into the grid during peak consumption hours, helping smooth short-term swings that can otherwise strain system balancing resources.

Grid connection and modular battery design

The facility is directly connected to Bulgaria’s national transmission network through a newly constructed 33/110-kV substation. Enery says the system comprises 120 battery units, each with an approximate capacity of 5 MW, creating a modular architecture intended to enable flexible operation and efficient dispatch.

Commercial structure via VPPA with Vitol

Operations will be managed through a virtual power purchase agreement (VPPA) with global energy and commodities trading company Vitol. The arrangement is intended to provide structured market integration for the stored energy, supporting commercial optimization as the asset contributes to balancing services.

Green financing arranged by DSK Bank

Financing for the project was secured through a green lending package arranged by DSK Bank, which is a member of the Hungarian OTP Group. The use of green finance underscores how lenders are backing large-scale infrastructure tied to the energy transition.

Implications for renewable integration in southeastern Europe

Enery expects the Nova Zagora facility to play a key role in supporting Bulgaria’s continued expansion of renewable energy sources, while also contributing to reduced reliance on electricity generated from fossil fuels. The commissioning also adds momentum to regional efforts: Southeastern European countries are increasingly investing in modernizing electricity systems and integrating higher shares of renewables into national grids.