National Electricity Company has successfully completed the refurbishment of hydro unit No. 3 of Chaira Pumped-Storage Hydropower Plant – a key stage in the restoration of the largest pumped-storage facility in the Balkans. The plant can now contribute effectively to the country’s electricity system with two hydro-generating units and a capacity of 420 MW – a significant contribution to the security and balance of the energy system.

Energy Minister Traicho Traikov personally oversaw the synchronization of the power station with the grid.

This achievement is the result of the development and successful implementation of an innovative engineering solution for modifying the turbine of the hydro-generating unit. The same solution has already proven its effectiveness in the refurbishment of hydro-generating unit No. 2, which currently has 3,300 operating hours. Implementing this solution took 15 months of intensive work and consistent joint efforts by the teams of the contractor consortium and NEK staff. The approach adopted for modification and modernisation represents a genuine innovation in the global hydropower sector.

Work on the phased restoration of Chaira PSHPP is continuing with the refurbishment of generating unit No. 1, carried out by the Japanese corporation Toshiba, which is the plant’s original equipment manufacturer. The hydro-unit remains in its original condition and has not undergone any repair work since it was commissioned in 1995. The expected completion date for the works is 2028.

It should be noted that, in order to ensure the sustainable long-term operation of Chaira PSHPP, NEK is preparing procedures for a public procurement process to completely replace hydro-generating units No. 1 and No. 4.

This large-scale project to refurbish the largest pumped-storage hydropower plants in the Balkans will make a significant contribution to the successful integration of growing renewable energy production across the region and to the achievement of decarbonisation targets at both national and European level. In this way, our country will position itself as a leading player in the transition to low-carbon energy and in the development of green energy storage solutions in South-Eastern Europe.