Green Energy Powers the ‘Country of Roses’: Sigenergy's 20 MWh Project Goes Live in Bulgaria

Sigenergy, in partnership with the leading Bulgarian energy company Trakia MT, has successfully completed a 20 MWh utility-scale co-located project in Malko Tarnovo, located in southern Bulgaria.

Driven by the dual goals of climate neutrality and energy autonomy, Europe is rapidly shifting toward a greener, more sustainable future. Integrated solar and storage systems are emerging as a key solution to address grid fluctuations and enhance the efficiency of renewable energy utilization. Known as the “Country of Roses,” Bulgaria is also making strong strides in its green and low-carbon energy transition. In line with this, this project enhances regional clean energy stability while boosting local energy independence and grid resilience.

As a highly integrated, fast-responding, and stable solar and storage solution, this project provides a replicable model for Bulgaria and the broader European region. It also highlights the vital role of energy storage systems in supporting the transformation of energy infrastructure toward greater sustainability and resilience.

Modular Design: 10-Day Installation, Ready for Seamless Expansion

Remarkably, the entire installation of this large-scale project was completed in just 10 days, with commissioning taking only 2 days. This efficiency is made only possible by Sigenergy’s highly modular C&I BESS solution.

The project deployed 90 units of Sigenergy’s 110 kW inverters, each paired with a 240 kWh SigenStack battery, achieving a total capacity of 20 MWh. Thanks to its modular, stackable design and plug-and-play connectors, SigenStack eliminates the need for complex wiring. Its lightweight, compact architecture also removes the need for specialized cranes or large construction equipment—significantly reducing installation complexity and cost.

Ms. Galina Peycheva-Miteva, Owner of Trakia MT Ltd., commented during the interview:"Due to the modular design of SigenStack, it’s so straightforward that just about anyone can do it—an impressive achievement. The team completed deployment in such a short time, without cranes or deep foundations. The system was almost as easy as stacking blocks."She added,“The structure of SigenStack is extremely installer-friendly. Even teams with little prior experience can get up to speed quickly.”

Compared to traditional cabinet-style solutions, Sigenergy’s C&I BESS offer greater operational flexibility—supporting solar-only, storage-only, PV & storage, and off-grid scenarios. Whether for new installations or retrofit upgrades, the system easily adapts to diverse application scenarios and project phases.

Maximizing Returns, Stabilizing the Grid: The Dual Role of Energy Storage under Dynamic Pricing

With Bulgaria’s adoption of a dynamic electricity tariff mechanism, energy storage systems are becoming increasingly vital for enhancing energy efficiency and maximizing financial returns. PV generation typically peaks around midday, while electricity prices surge during morning and evening demand peaks—creating a clear mismatch between generation and consumption value.

By integrating energy storage, this project captures excess solar power during the day and dispatches it during high-price periods, significantly improving revenue potential.

From a grid perspective, the storage system acts as a time-shifting buffer between generation and consumption. It supplies clean energy during peak demand hours, alleviating pressure on the grid and improving regional supply flexibility and reliability. This contributes to a more resilient and sustainable energy infrastructure for Bulgaria.

The Sigenergy’s C&I BESS features a fully integrated design with proprietary EMS (Energy Management System) and BMS (Battery Management System), eliminating the need for external data loggers. It supports parallel operation of up to 100 units, greatly simplifying deployment and avoiding the communication delays and coordination complexities common in traditional setups.

Thanks to Sigenergy’s pioneering full-networked communication architecture, the system can support up to 2,000 devices with synchronized 1-second response times, maintaining exceptional stability and responsiveness in multi-unit configurations. Real-time dynamic data is refreshed every 10 seconds across all users, ensuring continuous intelligent control over plant operations.

Leveraging this highly integrated and responsive system, Sigenergy enables not only precise charge/discharge scheduling based on electricity pricing but also agile adaptation to real-time market signals—maximizing energy utilization and return on investment.

6-Layer Safety Protection: Safeguarding C&I Projects

For utility-scale projects, safety is always the top priority. Due to their large system size and high equipment density, any incident such as battery thermal runaway or fire can have far-reaching consequences—far beyond that of residential or small-scale systems. Selecting a solution with high reliability and active protection capabilities is therefore critical to ensuring long-term operational stability.

The Sigenergy C&I BESS features a 6-layer battery safety protection mechanism, including: temperature sensors, internal fire suppression units, aerogel insulation, decompression valves, high-temperature-resistant insulation pads, and smoke detectors.

This multi-layered design allows early detection of thermal runaway at the source and a response time of less than one second, which is over 60 seconds faster than traditional systems—significantly improving fire control.

Each 12 kWh module is equipped with an independent fire protection unit, providing localized, pack-level safety response. This pack-level defense strategy helps prevent the spread of thermal events across the entire system, unlike conventional systems that respond slowly and offer limited isolation, increasing the risk of escalation.

Sigenergy’s advanced safety architecture offers project owners a highly controlled and truly dependable solution, delivering peace of mind for even the most demanding utility-scale deployments.

Free of Regular O&M: Smarter Management, Greater Reliability

Building on a high safety standard, Sigenergy's C&I BESS goes further by enabling intelligent and visualized operations and maintenance—from hardware to software. This allows for truly unattended, 24/7 high-efficiency O&M.

With an IP66 protection rating and a maintenance-free design, the system is capable of stable operation in a wide range of challenging environments. Real-time monitoring via the cloud platform provides instant insights into device status, charge/discharge efficiency, and alarms—eliminating the need for frequent on-site inspections and significantly reducing labor and maintenance costs.

As the Trakia MT team shared in an interview: “For us, Sigenstack is a state-of-the-art solution. It’s simple, scalable, and built on the latest technology. And moreover, with IP66 protection rating, I don't even need to worry about future operation and maintenance. This just far outperforms any other solution currently on the market.”

Thanks to modular system architecture, any local fault is precisely contained within a single 12 kWh module. With minimal technical support, a faulty module can be replaced on-site in under 2 hours—dramatically shortening the O&M cycle and improving system uptime.

In contrast, traditional cabinet-level systems often suffer from low efficiency and concentrated risks—where a single fault can affect up to 5MWh of capacity, requiring over 48 hours of repair time.

Driving Bulgaria’s Green Transition and Regional Energy Upgrade

The successful delivery of this project highlights Sigenergy’s all-round strengths—from system safety, operational stability, and fast deployment to intelligent O&M. It also strengthened Trakia MT’s confidence in Sigenergy’s product performance and delivery efficiency. Building on this solid cooperation, the family-owned company has announced a new 20 MWh energy storage partnership with Sigenergy to further accelerate its expansion in renewable energy.

As renewable energy continues to take up a growing share of the global energy mix, energy storage is rapidly evolving from a supporting role to a system cornerstone. Whether it’s stabilizing the grid, improving flexibility, or enhancing regional energy independence and security, energy storage is becoming an essential enabler. As Ms. Galina put it: “Storage is no longer a luxury—it’s a necessity. I’m proud that we’re ahead of the curve and helping shape what comes next for energy in the region.”

Looking ahead, Sigenergy will continue to expand globally, bringing its modular and intelligent C&I BESS solutions into more real-world applications. With a commitment to safety, efficiency, and sustainability, Sigenergy aims to help customerss worldwide build smarter, greener energy systems.