Romanian electricity transmission operator Transelectrica has completed a €51 million investment in voltage control infrastructure. The project is designed to strengthen the national grid’s ability to accommodate additional renewable generation and manage fluctuations in electricity flows. Transelectrica said the work supports improved operational capability as conditions on the network change.
The upgrade involved installing two advanced STATCOM systems at Sibiu Sud and Bradu substations. Each system is rated at ±150 MVAr. The operator said the combined configuration represents a first for Romania’s transmission system.
STATCOM systems for reactive power and voltage response
The STATCOM installations provide rapid reactive power compensation. Transelectrica said the equipment enables it to respond to voltage changes driven by shifting demand, renewable generation and network operating conditions. The project is aimed at addressing operational variability associated with changing generation and load patterns.
The operator linked the need for such equipment to technical challenges arising from rapid growth in wind and solar output. It said this can create substantial changes in network operating conditions, including voltage fluctuations and periods of reduced conventional generation. During low demand, high renewable output, or rapid changes in cross-border flows, reactive power control becomes particularly relevant.
Transelectrica stated that STATCOM technology allows transmission operators to regulate reactive power dynamically without relying entirely on conventional generating units for voltage support. It also noted that voltage control equipment does not automatically resolve every transmission bottleneck or increase the physical capacity of constrained power lines. The investment’s commercial value is described as improving network stability and operational flexibility while providing a stronger technical foundation for further renewable connections.
Timeline, financing and contractors
The investment was completed in August 2026, about nine months ahead of its May 2027 contractual deadline. The Sibiu Sud installation entered service in December 2025, followed by the Bradu system in May 2026. Both were operational before formal completion and inauguration of the project.
Financing came predominantly from the European Union’s Modernisation Fund, which covered almost the entire investment. Engineering and construction works were carried out by Siemens Energy and Electromontaj. The contract for the works was signed in 2023.
Renewables integration and grid flexibility considerations
The project is positioned as part of efforts to support integration of additional wind and solar capacity. Transelectrica said improvements in transmission system stability can help back new renewable connections by strengthening operational flexibility. It also indicated that as renewable capacity increases, similar investments in voltage control, digital monitoring and flexible network operation are likely to complement new power lines and substations.
