In February 2025 we concluded consultation on a short-list of investment options to ensure a reliable power supply for the upper South Island (from Twizel north).
Since then, we have undertaken further revision of our cost estimates, incorporating a more detailed understanding of the activities, resources and scope of work required. All cost estimates for short-listed options have increased, driven by requirements for transmission line upgrades which have proven more complex than we anticipated.
Our preferred option has increased to approximately $164 million, compared to the $77 million presented in our short-list consultation.
We have also continued to review our assumptions used in our benefit modelling, and a more accurate representation of constraints has led to greater benefits than initially estimated. Under the Transmission Pricing Methodology, this led to a change in the allocation of costs.
As such, we have conducted further consultation on this work, closing 5 May 2025.
The need and requirement for investment has not changed and remains essential to ensure voltage stability can be maintained in the upper South Island as electricity use increases further.
Documents for further consultation
- Upper South Island - further consultation document
- USI Attachment 1 - Need for Investment, Demand and Generation Scenarios
- USI Attachment 2 - Short-list of investment options
- USI Attachment 3 - Benefit modeling
- USI Attachment 4 - Options analysis
- USI Attachment 5 - Indicative starting BBI customer allocations
Having your say
Consultation closed on 5 May 2025.
What is the timeframe from here?
Following this consultation, we will consider the feedback we receive. Our plan remains to prepare and submit our Upper South Island MCP to the Commerce Commission in mid-2025.
Previous documents