Bac Ai hydropower works stay on track despite holiday period

The investor and contractors are maintaining construction activities through the festive period, with tunnelling, access roads, and core infrastructure works advancing as planned. The mountainous areas surrounding the site have seen increased construction activity, as equipment and materials are mobilised to support ongoing works and ensure milestones are met.

Since the commencement of phase two last February, the project has recorded considerable progress, laying a solid foundation for the main construction work. Temporary camps, auxiliary facilities, and power and water supply systems for construction have been installed. The open-section construction road network has been largely completed, ensuring smooth transportation of materials and equipment and enabling the effective organisation of large-scale underground works.

At present, contractors are focusing their resources on tunnel excavation and reinforcement, the backbone of the pumped storage hydropower scheme. Construction is being carried out continuously, day and night. Five tunnel excavation fronts are operating simultaneously, demonstrating a high level of coordination and technical capability.

To date, approximately 3,178m out of a total 17,000m of tunnel excavation and reinforcement have been completed. The achieved workload fully meets the approved schedule. According to the construction plan, by early February, excavation is expected to reach the underground powerhouse area, a critical milestone that will significantly accelerate subsequent works and ensure the project remains on track.

Speaking from the site, Le Dinh Lam, executive director of the contractor consortium for the Bac Ai Pumped-Storage Hydropower project, noted that progress to date has exceeded expectations of the investor and the contractors.

Lam said that the contract and bidding documents set an excavation target of approximately 90m per month. However, actual performance has been far more positive. “All five excavation fronts have achieved at least 120m per month. In particular, the VH3 tunnel recently reached 180m per month, double the originally expected rate,” he noted.

Beyond individual construction fronts, the contractor consortium has reviewed and addressed each issue to shorten the overall construction timeline, compensating for delays encountered in the early stages due to site clearance issues. “Land clearance has now been completed, and we are closely following the schedule to ensure the first generating unit comes into operation by the end of 2029, the fourth unit by the end of 2030, and the entire plant in June 2031 as planned,” Lam said.

A notable aspect of the Bac Ai project is the continuity of construction during public holidays. Despite the four-day New Year break, work at the site continued under organised shift arrangements.

“By the end of January, EVN and the contractor consortium will review 2025 performance and launch the 2026 emulation campaign to maintain momentum and efficiency,” Lam said.

While workers are expected to have a short Lunar New Year break, construction will resume soon afterwards. “We are considering allowing staff and workers three to five days off for Tet, after which they will return to the site early to avoid any disruption to progress,” he added.

A key factor supporting the project’s construction pace is the extensive use of modern equipment. According to Lam, the volume of machinery mobilised is about three times the minimum requirement, ensuring continuity even in the event of breakdowns. Most equipment comprises integrated drilling, blasting, and mucking systems.

“Twenty years ago, five excavation fronts would have required 1,000 to 2,000 workers. Today, with mechanisation, the site operates with around 300 workers, while construction is faster and safer,” he said. Ventilation, drainage, and high-capacity hauling systems have also been deployed to support safe and efficient underground operations.

Bac Ai is the first pumped storage hydropower project in Vietnam and a nationally important infrastructure undertaking, playing a critical role in ensuring energy security and balancing the national power system.

It has a total installed capacity of 1,200MW. It utilises the Song Cai Reservoir, part of the Tan My irrigation system, as the lower reservoir, with an underground powerhouse and a water head of more than 400 metres. The pressure tunnel system comprises two tunnels with a total length of 1,719m, including a vertical shaft exceeding 400m.

The project also includes a component connecting the plant to the national grid via a double-circuit 500kV transmission line approximately 18.8km long, linking to the 500kV Ninh Son Substation. The total investment is estimated at VND21.1 trillion ($800 million), funded by EVN's equity and loans from six international financial institutions.

Currently, the main electromechanical equipment package is in the contractor selection phase and is expected to be awarded in the second quarter of 2026, forming a crucial basis for maintaining the overall project schedule.

EU offers $500 million package to facilitate Vietnam's Just Energy Transition The European Commission and other European actors have announced a comprehensive €430 million (nearly $500 million) package to advance the Bac Ai Pumped Hydro Storage project, a flagship investment under Vietnam's Just Energy Transition Partnership (JETP).

EVN launches major power infrastructure projects national Vietnam Electricity has launched and inaugurated major power infrastructure projects nationally, strengthening the national energy system ahead of the 14th National Congress.

EVN and AFD sign credit agreement for Vietnam's first pumped storage hydropower plant Vietnam Electricity (EVN) and the French Development Agency (AFD) signed a credit facility agreement worth €76 million ($89.5 million) for the Bac Ai Pumped Storage Hydropower Plant on December 26.