Bulgaria's energy system will be able to count on 735 MW after the successful completion of the rehabilitation of the Sestrimo HPP

The last stage of the repair of the "Sestrimo" HPP, and with it the rehabilitation of the "Belmeken-Sestrimo-Momina gorge" cascade has been successfully completed. With this, the country's electricity system will be able to count on reliable production from the full capacity of 735 MW from the cascade after the rehabilitated hydroelectric plant (HPP "Sestrimo") is put into operation. This is the fourth rehabilitated plant in the last 13 months. This is important for the entire energy system of the country, especially in the decarbonization stage, and hydroelectric power plants enable flexible production. This was said by the executive director of the National Electric Company (NEC), Martin Georgiev, during the official ceremony on the occasion of the completion of the repair works at the Sestrimo HPP. The investment for the rehabilitation of the Sestrimo HPP is worth EUR 20 million.

"At the end of last year, the plant celebrated its 50th anniversary and I hope it will continue to work for as long," Georgiev said.

"We realize how important the work of this plant is for providing green energy for Bulgaria. With such a complex project, there are also difficulties that were solved thanks to cooperation", noted the representative of the representative of the contractor consortium KONČAR KET - ČKD BLANSKO - RUDIS, Tihomir Vunich. "The most important thing is that the final result is a perfectly functioning plant that is of a very good level and quality," Vunich added.

Official Deputy Minister of Energy Georgi Samandov compared the production of the "Belmeken-Sestrimo-Momina gorge" cascade with the capacities of one of the units of the Kozloduy NPP. "The flexibility of hydropower capacities is a key element for the operation of the energy system (of Bulgaria)," he pointed out, drawing attention to the role of hydroelectric power stations at peak load. "In pumping mode, the same water resource is used, which turns pumped-storage plants into a kind of batteries for green energy. At the moment, our country uses low-carbon sources of over 70%, such as renewables, with hydroelectric power already accounting for over 50%," he added. In his words, this puts our country on a par with countries like France and Germany.

The Deputy Minister of Energy reminded that in May 2018, a contract was signed between NEC and the KONČAR KET - ČKD BLANSKO - RUDIS consortium for the rehabilitation of the plants that are part of the "Belmeken-Sestrimo-Momina gorge" cascade. The aim of the project is to improve operational capacities and improve the opportunities to participate in the regulation of the frequency and voltage of the network, as well as to supply corridors for emergency restoration of the energy system.

"The average annual production of electricity is 291 GWh, and the electricity produced by the Sestrimo HPP since its commissioning until now is nearly 12 billion kWh, which is the one-year consumption of all household consumers of electricity in the country. The plant has worked for a total of about 168,000 hours or 20 years without interruption, which speaks of reliability and security," said Deputy Minister Samandov.

He specified that comprehensive rehabilitation activities have been completed at Sestrimo HPP, and the project has been implemented within the framework of the signed grant agreement with the European Bank for Reconstruction and Development as administrator of the International Fund for the decommissioning of units from the Kozloduy NPP (KIDSF)... The total budget of the agreement is 37 million euros, of which 70 percent are European funds under KIDSF, and 30 percent are provided by own funding from NEC. The value of the rehabilitation of the "Sestrimo" HPP itself is slightly over 4.4 million euros.

The Acting Minister of Environment and Water, Petar Dimitrov, also expressed hope for the efficient operation of the facilities in the next 15 years at the Sestrimo HPP. He added that the MoEW is a reliable partner for the implementation of green policies.

The executive director of NEK expressed congratulations for the work of the plant's team, NEC, EIB and the contractor. A congratulatory address was also delivered to the head of the Sestrimo HPP, Ivan Kokalanov.

"Sestrimo" HPP is the second stage of the largest hydropower cascade in Bulgaria - "Belmeken-Sestrimo-Momina gorge. The plant is the third largest production capacity within NEC. In 2023, 50 years were marked since the commissioning of the first hydro unit.

The plant itself is derivation with two Pelton type turbines, vertical, and the installed capacity is 240 MW. The primary energy source is the water from the Belmeken dam.

Through a tunnel and an underground pressure pipeline with a total length of 5000 m, the water from the leveler Stankovi Bari after the "Belmeken" PSHP reaches the HPP "Sister."

The "Belmeken-Sestrimo-Momina Gorge" cascade has a total installed capacity of 735 MW in generator mode and 104 MW in pumping mode.