Enery launches Central and Eastern Europe’s largest 600 MWh BESS facility in Bulgaria

Vienna-based renewable energy developer Enery has commissioned the Nova Zagora Battery Energy Storage System in Bulgaria. The facility, with a power capacity of 150 MW and a total storage capacity of approximately 600 MWh, is presented by the company as the largest battery energy storage system in Central and Eastern Europe.

The project is located near Nova Zagora in central Bulgaria and has been developed as a standalone BESS facility. This means that the storage system operates as an independent energy infrastructure asset, not directly tied to a single solar or wind power plant.

The facility began commercial operation in March 2026. Its four-hour storage configuration — 150 MW of power and around 600 MWh of capacity — enables it to support grid balancing, smooth peak demand, store surplus renewable electricity and release it back into the grid when needed.

In technological terms, Nova Zagora BESS represents an important step for Bulgaria’s energy system, which is rapidly increasing the share of solar and other renewable generation. Large-scale battery systems allow electricity to be stored during periods of high renewable output and supplied to the grid during periods of higher demand or reduced generation.

This makes such facilities a critical component of the new energy infrastructure emerging across South-Eastern Europe.

According to the company, the integration of advanced technologies such as BESS will play a key role in ensuring reliable, efficient and future-ready energy infrastructure. The project is also important in the context of Bulgaria’s energy transition, particularly in regions historically associated with coal-based generation.

The financing of the Nova Zagora BESS project was supported by DSK Bank, part of Hungary’s OTP Group. In December, Enery secured green financing for the facility, underlining its role as a model for the next generation of energy storage projects in South-Eastern Europe.

IDR comment

The Institute of Danube Research considers the launch of Enery’s large-scale BESS facility in Nova Zagora a significant development not only for Bulgaria, but for the entire South-Eastern European energy space.

The region is moving from a model in which energy security was mainly associated with generation capacity and fuel imports towards a model where flexibility, balancing, storage and digital management of power systems are becoming increasingly important.

For Ukraine, this experience has practical relevance. Wartime pressure on the Ukrainian energy system has shown that resilience depends not only on large power plants, but also on the system’s ability to respond quickly to shortages, peak loads, emergency outages and fluctuations in renewable generation.

Large-scale battery storage systems can therefore become an important instrument for Ukraine’s post-war recovery and energy modernisation.

Such solutions are particularly relevant for Ukraine’s southern regions, including Odesa Oblast and the Danube region. Several factors intersect here: the development of renewable energy, the energy needs of port and logistics infrastructure, cross-border energy links with Romania and Moldova, and the need to provide stable power supply to critical facilities.

“The Enery project in Bulgaria demonstrates that the energy transformation of South-Eastern Europe is entering a practical phase. Large-scale battery storage systems are no longer experimental technologies; they are becoming infrastructure tools for grid stability, renewable energy integration and energy security. For Ukraine, especially its southern regions and the Danube direction, this experience is an important reference point for rebuilding the energy system on a new technological basis,” the Institute of Danube Research notes.

In the broader regional context, Nova Zagora BESS can be viewed as part of a new energy belt in South-Eastern Europe, where Bulgaria, Romania, Moldova and Ukraine are increasingly connected by a common logic of energy security, decarbonisation and integration with the European electricity market.

For Ukraine, it is important to take this experience into account when preparing recovery projects — from local BESS solutions for communities and critical infrastructure to large-scale storage systems capable of operating at the level of regional energy hubs.

In this approach, battery storage facilities can become not only a supporting element for renewable energy, but a full-fledged component of the resilience of the state and its regions.