The National Electricity Company (NEK) has confirmed that unit 2 at the Chaira pump-storage hydropower plant in southwestern Bulgaria successfully completed a 72-hour testing phase on January 9, proving its readiness to support the national electricity network. The facility plays a critical role in balancing peak electricity demand during winter by operating in both generator and pump modes as needed.
At the start of 2025, NEK launched repair and rehabilitation efforts for units 1 and 3. Japan’s Toshiba Corporation has been contracted to refurbish unit 1, which has remained unchanged since its commissioning in 1995. As the original manufacturer, Toshiba will introduce modern technical solutions to enhance safety and efficiency.
For unit 3, an agreement was signed with the Austrian ABB/Voith consortium to conduct similar rehabilitation work to that recently completed on unit 2. The generator and turbine components have already been dismantled, and preparations are underway to assess their condition.
NEK has also initiated the process for a full replacement of units 1 and 4, receiving five bids for the project. The selection process is ongoing, with further evaluations and a second tender phase yet to be completed.
This update follows statements from Yordan Ivanov and Atanas Atanassov of Continue the Change-Democratic Bulgaria, who raised concerns that none of the plant’s units are currently operational, posing challenges for Bulgaria’s electricity balancing system. NEK’s response aims to clarify the progress of restoration efforts at the country’s largest hydropower facility.
