Bulgaria’s state-owned power utility, NEK, has signed contracts with Toshiba and the Voith-ABB consortium to repair units 1 and 3 of the Chaira pumped storage hydropower plant. The repairs are necessary due to extensive damage sustained by generators in units 1 and 4 three years ago, which now require replacement.
Earlier this year, NEK successfully restored unit 2 of the Chaira system to regular operation after completing necessary tests. This marks a significant step toward fully repairing the largest pumped storage hydropower plant in Southeastern Europe.
The Chaira plant, with a pumping capacity of 784 MW and a generation capacity of 864 MW, has been offline since May 2022. The facility has experienced multiple failures, partly due to unsuccessful rehabilitation efforts in the past.
Toshiba to Repair Unit 1
NEK has contracted Toshiba, the original manufacturer, to repair unit 1. The Japanese company built units 1 and 2 in 1995, with units 3 and 4 following in 1999. The repair work, set to begin soon, aims to restore unit 1’s safe operation by next year. Bulgarian Energy Minister Vladimir Malinov and Japanese Ambassador Hisashi Michigami attended the contract signing ceremony.
Units 1 and 4, equipped with reversible turbines, are beyond repair and will be replaced. NEK issued a joint tender for their replacement in September.
Voith-ABB Consortium to Handle Unit 3
The Austrian consortium of Voith and ABB, which previously repaired unit 2, will now rehabilitate unit 3. The consortium plans to use a similar engineering solution to restore the unit. NEK has already dismantled the generator in preparation for the repairs.
Chaira’s Role in Bulgaria’s Energy System
The Chaira plant is part of the Belmeken-Sestrimo-Chaira hydropower complex, the largest of its kind in Bulgaria. NEK recently completed the rehabilitation of the Belmeken pumped storage plant in February, which has five units with a total generation capacity of 373.5 MW, including two reversible units with a pumping capacity of 104 MW.
Bulgaria’s third pumped storage system, Orphey, is located inside the Dospat Dam in the south. It has four turbines with a combined capacity of 164.8 MW, including one reversible unit with a pumping capacity of 47.4 MW.
Plans for Expansion
Bulgaria is also developing two new pumped storage hydropower projects. According to the country’s draft energy strategy through 2053, the Chaira plant’s capacity will be expanded. Additionally, the Ministry of Energy has allocated significant funding for battery energy storage systems (BESS) to support the integration of renewable energy.
However, Bulgaria faces challenges in securing European Union funding due to an ongoing political crisis that has persisted for over three and a half years. Despite these hurdles, the government remains committed to modernizing its energy infrastructure.
Related topic:
- Ontario Power Generation Shuts Down Pickering-4 Nuclear Plant
- Winter Storm Leaves Kentuckians Without Power
- Singapore to Build Hydrogen-Ready Power Plant for Low-Carbon Transition
