Oven Mountain Pumped Hydro Energy Storage

  • Snapshot

Oven Mountain Pumped Hydro Energy Storage (PHES) is a proposed 900 MW, eight-hour pumped hydro facility on private land between Armidale and Kempsey, within the New England Renewable Energy Zone. Developed by Oven Mountain Pumped Storage with Alinta Energy, the ‘off-river’ scheme would store and dispatch renewable energy to firm the grid alongside the zone’s wind and solar.

Turnbull Engineering was engaged by the Gamuda Ferrovial Joint Venture during the project’s Early Contractor Involvement (ECI) phase to validate constructability and optimise more than 40 kilometres of access roads and civil infrastructure across steep terrain.

  • Location
    Between Armidale and Kempsey, NSW (New England REZ)

  • Development
    Oven Mountain Pumped Storage (OMPS) with Alinta Energy

  • Capacity
    900 MW, 8-hour (up to 7.2 GWh)

  • ECI contractor
    Gamuda Ferrovial Joint Venture

  • Turnbull’s role
    Constructability and access road / civil optimisation (ECI phase, 2024-2025)

  • Estimated Capex
    Multi-billion-dollar (est. $2 billion+)

  • Program
    2022-2029

  • Status
    Proposed: pre-approval and pre-final investment decision

Project Overview

The ‘off-river’ scheme would use two reservoirs at different elevations, connected by tunnels to an underground power station, to store and release energy, generating up to 900 MW and holding around eight hours (up to 7.2 GWh) of dispatchable energy at full output, enough to power more than 600,000 homes.

Sited in the New England REZ, the project is intended to firm the grid alongside the region’s wind and solar and support the National Electricity Market’s transition away from coal. It is classified as critical State Significant Infrastructure and remains in development. It has not yet received final approvals or reached a final investment decision, and construction has not commenced.

 
 

Services

  • Access roads and tracks, incorporating geological mapping to optimise each segment of road — reducing footprint and maximising re-use of excavated material

  • Temporary and permanent bridges

  • Temporary working platforms for site facilities and accommodation camps

  • Sitewide temporary utilities

  • Snapshot

Turnbull’s Role

Alinta Energy appointed the Gamuda Ferrovial Joint Venture (GFJV) as Early Contractor Involvement partners to progress the project’s design and constructability. Turnbull Engineering was engaged by GFJV to bring civil and constructability expertise to the access and enabling infrastructure — validating constructability and optimising more than 40 kilometres of access roads and civil works across challenging, steep terrain.

Project Highlights

  • ECI on a major pumped hydro project

    Turnbull contributed civil and constructability expertise to one of NSW’s most advanced proposed pumped hydro projects during its Early Contractor Involvement phase, working within the Gamuda Ferrovial JV team.

  • Optimising civil works in steep terrain

    Geological mapping was used to optimise each segment of more than 40 kilometres of access roads. This reduced the project’s footprint and maximising re-use of excavated material.

  • Full enabling-infrastructure scope

    Beyond roads, the scope spanned temporary and permanent bridges, temporary working platforms for site facilities and accommodation camps, and sitewide temporary utilities.

  • Long-duration storage for the transition

    At 900 MW for eight hours, the facility would provide up to 7.2 GWh of dispatchable storage to firm the New England REZ’s wind and solar as coal-fired power retires.

By the numbers

900 MW

generation capacity

7.2 GWh

8 hour storage

40+km

access roads optimised

600,000+

homes powered

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