Romania’s electricity transmission operator Transelectrica has completed a €51 million investment in voltage control infrastructure. The project was designed to strengthen the national grid’s ability to accommodate additional renewable generation and manage fluctuations in electricity flows. Transelectrica said the work supports the system’s capacity to respond to changing operating conditions.
STATCOM installations at Sibiu Sud and Bradu substations
The upgrade includes two advanced STATCOM systems, each rated at ±150 MVAr, installed at the Sibiu Sud and Bradu substations. The equipment provides rapid reactive power compensation. This allows the transmission operator to respond to voltage changes linked to shifting demand, renewable generation and network operating conditions.
Transelectrica stated that the combined configuration represents a first for Romania’s transmission system. The Sibiu Sud installation entered service in December 2025. The Bradu system followed in May 2026, with both units operational before formal completion and inauguration of the project.
Timeline, financing and contractor details
The investment was completed in August 2026, about nine months ahead of its May 2027 contractual deadline. Financing came predominantly from the European Union’s Modernisation Fund, which covered almost the entire investment. Engineering and construction were carried out by Siemens Energy and Electromontaj.
The contract for the engineering and construction works was signed in 2023. Transelectrica said the project addresses an increasingly important technical challenge for Romania’s electricity system. Rapid growth in wind and solar generation can create substantial changes in network operating conditions, including voltage fluctuations and periods of reduced conventional generation.
Role of dynamic reactive power control for renewables integration
STATCOM technology enables transmission operators to regulate reactive power dynamically without relying entirely on conventional generating units for voltage support. Transelectrica said this is particularly relevant during periods of low electricity demand, high renewable output or rapid changes in cross-border flows. For developers of new wind and solar projects, improved transmission stability can support the integration of additional generating capacity.
The operator also noted that voltage control equipment does not automatically resolve every transmission bottleneck or increase the physical capacity of constrained power lines. It said the commercial value of the investment lies primarily in improving network stability and operational flexibility while providing a stronger technical foundation for further renewable connections. As renewable capacity increases, similar investments in voltage control, digital monitoring and flexible network operation are expected to complement new power lines and substations.
