Bunnythorpe-Haywards A and B lines conductor replacement project

Transpower advised that the conductors of these lines had reached the end of their economic lives and needed to be replaced. Under the regulatory rules, Transpower could have replaced the existing conductors and maintained the existing capacity of the lines under its base capital works programme but had to seek approval from us to increase the capacity of the lines.

On 31 August 2019, Transpower New Zealand Limited applied to us to amend one of the outputs of the Bunnythorpe Haywards Lines A and B upgrade major capex project.

The purpose of the project is to replace the ageing wires on two of the transmission lines between Bunnythorpe Haywards substations. While delivering this project Transpower identified that the new wires could initially produce increased levels of noise compared to the current noise levels. The noise levels during wet conditions. The level of noise produced by the new wires is expected to show a steady reduction over the first 100 days after stringing, and is then expect to reduce over time.

Transpower is seeking to amend the specified outputs in order to install another type of wire on sections of the lines that are close to residential areas. The noise levels from the proposed wires decrease at a faster rate.

We intend to make a decision on this application in December 2019.

As further background you might also be interested in this communication.