Hidden Valley Gold and Silver Mine

For this new open-pit mine in remote Papua New Guinea, we delivered power transmission infrastructure.



Project Status

  • Completed 2009

The Hidden Valley Mine is situated in the remote Morobe Province of Papua New Guinea (PNG), where there was limited power infrastructure before the new open-pit mine was built.


PNG Power engaged WSP to design and deliver the power transmission infrastructure to provide a secure electricity supply of 20 megawatts.


Comprehensive Services

The project included the design of:

  • 105 kilometres of 132 kV single-circuit transmission line with optical ground wire
  • 132 kV six-bay switchyard at the grid connection
  • 132 kV three-bay switchyard at the mine site
  • The communications interface for the grid control.


Our scope of work included:

  • Corridor selection and detailed transmission line design
  • Development of the project implementation plan and cost estimate
  • Electrical system studies
  • Specification documents for the contract
  • Factory witness testing
  • Conceptual design for the connection assets
  • Technical specification development for the proposed 132 kV connection substations at Erap and Hidden Valley


Valuable Outcomes

The project enabled PNG Power to fulfil its power supply obligations to the mining joint venture. In 2009, the mine’s first gold was poured and in 2010, the mine was officially opened. It is now a gold and silver mine, which is expected to operate until 2024 with the possibility of extension. PNG Power provides power to the mine from two hydro schemes.