Construction at the Bac Ai pumped storage hydropower project, a 1200MW facility being developed by Vietnam Electricity (EVN), has advanced ahead of schedule on several key work packages, allowing the project to move into its main construction phase in early 2026.
The project, located in Bac Ai Tay Commune, Khanh Hoa Province, began construction in February 2025 and represents a total investment of approximately VND 21.1 trillion. When completed, the four-unit pumped storage facility is scheduled to commission its first unit in December 2029, with full commercial operation expected by the end of 2030.
Progress and construction priorities for 2026 were reviewed at a site coordination meeting on January 26, chaired by EVN Vice President Pham Hong Phuong. Representatives from EVN’s Power Project Management Board No. 3 (EVNPMB3), Power Engineering Consulting Joint Stock Company No. 4 (EVNPECC4), international consultant SSC, and major contractors attended the meeting.
According to EVNPMB3, preparatory and enabling works were largely completed in 2025. Construction and operational access roads were connected across the site, open excavations for major foundations were finalised, and excavation and initial support works for five adits were completed in line with contractual milestones.
Excavation and structural support for the electrical cable tunnel and ventilation tunnel reached 100% completion on January 21, 2025, exceeding the annual schedule. Earthworks for the planned 500kV switchyard platform achieved a volume of 145,000 cubic meters in 2025, representing 144% of the annual target and approximately 90% of total planned works.
Road packages VH1, VH2, and VH3A reached between 96 and 98% completion of designed earthwork volumes. VH1 achieved full completion of roadbed excavation and embankment. Underground works, including operation, ventilation, and drainage tunnels, exceeded quarterly production targets, reaching between 104 and 117% of planned volumes in several sections.
Project procurement also advanced during 2025, with 28 of 32 construction and supply packages awarded. Land acquisition and resettlement activities were completed across 106.4 hectares, enabling full access to the main construction areas. Total capital disbursement reached approximately VND 434.4 billion in 2025, exceeding the EVN-approved annual budget.
EVNPMB3 confirmed that construction of the main underground powerhouse complex began on January 22, 2026. From the first quarter of 2026, project teams will prioritise critical-path activities as the project enters its peak construction period.
Environmental and social compliance remains a key focus. EVN aims to complete approval of the Environmental and Social Impact Assessment (ESIA) and the Environmental and Social Management and Monitoring Plan (ESMMP) by the end of March 2026. International consultant SSC is providing independent oversight of environmental, social, health, and safety performance.
Once operational, the Bac Ai pumped storage plant is expected to play a central role in grid stabilisation and renewable energy integration in southern and central Vietnam, providing peak shaving, frequency regulation, and reserve capacity.
