Hydropower provides Nevada with 1GW of on-demand electricity

The underground powerhouse will contain three variable-speed pump turbines and the project will provide network frequency regulation, generating and pumping operating flexibility, and rapid response to power fluctuations.

Following a pre-feasibility study, we were appointed Owner’s engineer to deliver a detailed feasibility study that includes scrutinising the already developed concepts, collecting additional data, evaluating technical viability, and advancing the engineering of the project. We are also supporting rPlus to secure a licence for the project from the Federal Energy Regulatory Commission (FERC).

Pending engineering and environmental approvals and the completion of the FERC licensing process, construction is expected to begin in 2025. Construction will take between five and seven years.

White Pine PHS will provide 8000MWh of energy storage to generate up to eight hours of electricity and provide direct employment and secondary jobs to improve the White Pine County economy, helping Nevada meet its goals for a carbon-free energy future.

Optimising the preferred option

The project is almost entirely located on federal land. Challenges include sensitive habitat, a historic railroad, difficult access to the upper reservoir site, and complex geological conditions.

A value planning workshop consisting of our global experts generated 386 ideas in 10 categories. These were screened and developed into six alternatives.

We then used 3D AutoCAD and LeapFrog software to develop 3D models that included geological conditions and detailed representations of each key element. To support our investigations, we also supervised a detailed LIDAR survey of the site.

Working with the client, we selected preferred options for dam types and locations, route, size and shape of the headrace tunnel, and alternatives for the powerhouse location and tailrace arrangements. This identified design improvements and potential time and cost savings. These include:

• Developed design for the reservoirs to make best use of locally sourced material, while balancing cut and fill
• Increased scheme head by a utilizing turkey’s nest reservoir
• Reduced length of high-pressure waterways by shifting the powerhouse cavern as close as possible to the vertical pressure shaft
• Reduced length of access and cable tunnels, while adopting slopes compatible with the geotechnical characteristics of the soil and rock as well as construction technologies

Underground experience

Geological and groundwater conditions associated with constructing a deep shaft, multiple tunnels, and large caverns require careful analysis and managing and our extensive global underground experience means we have the knowledge and tools to assess a PHS project against these risks.

On the White Pine Pumped Storage Project, our tunnel, hydro and electromechanical specialists worked together to configure the alignments of all waterways – intake, outlet, shaft, tunnel and penstock – to suit the geotechnical conditions and the optimal pump-turbine configuration. This included consideration of alternative materials and of different angles for the waterways.

Our studies to date have developed viable alternatives that address project risks, flexibility requirements and construction costs.

*All stats are provisional