In September 2025 Transpower submitted a major capex proposal for the first stage of work to renew the critical High Voltage Direct Current (HVDC) electricity link between the North and South Islands, applying for Commerce Commission approval to invest $1.1 billion to deliver the major infrastructure elements of the work.
The proposal includes the replacement of three submarine electricity cables, the addition of a fourth cable to boost electricity transfer capacity, new cable termination stations on either side of Cook Strait, spare cable storage, a filter bank upgrade at Benmore and a scheme to raise the overload capacity of Pole 2.
The Commerce Commission is now reviewing the proposed investment.
Read our news story on the proposal here.
Main proposal document:
Overview - HVDC Link Upgrade Programme Major Capex Proposal (Stage 1)
Supporting documents:
Attachment 1 - HVDC MCP (Stage 1) Compliance with the CAPEX IM
Attachment 2 - HVDC MCP (Stage 1) Need, Demand and Generation Scenarios
Attachment 2 Addendum - Appendix B - Demand Figure Data
Attachment 3 - HVDC MCP (Stage 1) Cable Condition Assessment Report
Attachment 4 - HVDC MCP (Stage 1) Short list of Investment Options
Attachment 5 - HVDC MCP (Stage 1) Costing Report
Attachment 6 - HVDC MCP (Stage 1) Benefits Modelling
Attachment 7 - HVDC MCP (Stage 1) Application of the Investment Test
Attachment 8 - HVDC MCP (Stage 1) Stakeholder Engagement
Attachment 9 - HVDC MCP (Stage 1) TPM and Indicative Pricing Impacts
Attachment 10 - HVDC MCP (Stage 1) Chief Executive Certification
Independent review:
Independent Review - HVDC Link Upgrade Programme
Webinar HVDC Link Upgrade MCP (Stage 1) - 9 September 2025