The Bac Ai power project is a 1.2GW pumped storage hydroelectric power plant under construction in the Ninh Thuan province of Vietnam.

The project is being developed in two phases by state-owned company Vietnam Electricity (EVN) with an estimated investment of £695.2m ($909.73m).

Civil construction works on the project were commenced in January 2020, while the facility is expected to be completed by 2028.

Location and site details

The Bac Ai pumped storage hydropower project is located in the Phuoc Hoa and Phuoc Tan communes of Bac Ai district, Ninh Thuan province, in Vietnam.

The project site lies approximately 65km west-northwest of Ninh Thuan province’s capital city Phan Rang–Tháp Chàm.

Bac Ai power project development details

The Bac Ai power project is one of the power generation projects approved by the government in March 2016 under the national electricity development plan. It is the nation’s first pumped storage hydropower plant that will help in stabilising the national power system and provide power to meet the peak load demand.

The first phase of the project involves the development of discharge gate cluster to facilitate water storage in the lower reservoir. It includes the construction of discharge channels, pressure tanks, and supply and installation of hydro-mechanical and auxiliary systems.

The second phase will focus on the main construction works of the power plant.

Reservoir and dam details

The Bac Ai pumped storage power plant will feature an upper reservoir (artificial lake) with a dam height of 72m to be constructed on top of the Da Den mountain. The upper reservoir will be designed with an effective volume of nine million cubic metres (Mcm) and normal rising water level of 603m.

The lower reservoir, with a dam height of 38.4m, will be created utilising the water from the Song Cai reservoir sourced through the Tan My irrigation system developed by the Ministry of Agriculture and Rural Development. It will be designed with an effective volume of 200Mcm and a normal water level at 193m. The available volume for the lower reservoir will be approximately 10Mcm.

The water from the lower reservoir will be pumped to the upper reservoir through two discharge tunnels. Each discharge tunnel will be 2,700m long and have a diameter ranging between 5.5m and 7.5m.

Bac Ai pumped storage hydropower project make-up

The Bac Ai pumped storage hydropower project will be equipped with four power units of 300MW capacity each. Each unit will consist of reversible pump turbines and reversible motor generators, placed in an underground powerhouse near the lower reservoir.

The power plant will be designed to operate at a water head of 403m with a maximum discharge capacity of 248m3/s.

Contractors involved

The consortium of Construction Joint Stock Company 47 and Narime-Lilama 10 is the construction contractor for the outlet cluster work of discharge gates under phase one.

Power Construction Consultant Joint Stock Company 4 (PECC4) was awarded a contract worth £3.16m ($4.4m) by EVN in April 2021 for providing consulting services for phase two. The scope includes technical design, construction drawings, and preparation of bidding documents.

Power Engineering Consulting Joint Stock Company 2 (PECC2) was contracted to provide design review services.

Power Project Management Board Number Three (PMB3) was engaged as the representative of EVN to co-ordinate with the contractors and the consulting units and perform site supervision.