HVDC Grid Upgrade Proposal - archive

Background

Transpower submitted its proposal to decommission and replace the HVDC inter-island link pole 1 as a “reliability investment” in its 2005 grid upgrade plan (GUP) on 30 September 2005.

On 21 October 2005, the Commission wrote to Transpower stating its view that the HVDC Proposal should be considered as an “economic investment” rather than a reliability investment. On the 8 December 2005, Transpower confirmed its acceptance that the HVDC Proposal could be treated as an economic investment.

In June 2006, the Commission agreed to Transpower's request that consideration of the proposed HVDC link upgrade (that was submitted as part of a GUP in September 2005) be suspended, given a number of unresolved issues relating to the application of the Grid Investment Test (GIT). The GIT was described in Schedule F4 of part F of the Electricity Governance Rules 2003 (Rules).

The work the Commission and Transpower undertook as part of the interim work phase for the North Island Grid Upgrade Proposal resulted in greater clarity around the application of the GIT. It resolved many of Transpower's issues with the application of the GIT and enabled Transpower to submit a revised HVDC proposal as an economic investment in May 2008.

Transpower's application (May 2008)

On 2 May 2008, Transpower sought approval for $728 million for a grid upgrade plan which included a two stage process:

  • stage 1: procuring, constructing and commissioning a new thyristor-based 700 MW pole and associated equipment (converters, condensers, new control systems, transformers, etc) at Haywards and Benmore by 2012; and
  • stage 2: increase the link capacity to 1200 MW (scheduled for 2014).

The proposal was submitted as an economic investment and formed part V of Transpower's Grid Upgrade Plan submitted in September 2007.

Attachments

Timetable and Amendments

In late 2007 the Commission and Transpower agreed the following timetable and process for consideration and approval of the HVDC proposal.

The agreed timetable lapsed on 13 June 2008 as the Commission had sought but not received further information from Transpower to ascertain the reasonableness of the costs used in the GIT. On 13 June 2008, the Commission and Transpower agreed a revised timetable (“June 2008 timetable”). This timetable assumed that all the information necessary for the Commission to make a decision was to be provided by 19 June 2008.

The agreed timetable lapsed on 9 July 2008 as the Commission was not in a position to make a decision at its 1/2 July Board meeting as anticipated given that further work was required on establishing the appropriate level of approval. On 9 July 2008, the Commission and Transpower agreed a revised timetable (“July 2008 timetable”). This timetable assumed that all the information necessary for the Commission to make a decision would be provided by 17 July 2008.

The July 2008 timetable lapsed on 17 July as Transpower was not in a position to consider fully the Commission's comments and clarify or revise its Proposal by the due date as anticipated. On 21 July 2008, the Commission and Transpower agreed to a new timetable (“21 July 2008 timetable”).

Notice of Intention (July 2008)

On 31 July 2008, in accordance with rule 15.1 of section III of part F of the Electricity Governance Rules 2003, the Commission published a notice of its intent to approve Transpower's HVDC Proposal.

Reasons for Decision (July 2008)

The document below presents the Commission's analysis of the HVDC proposal and explains the reasons supporting the Commission's intention to approve the HVDC proposal

The Commission was assisted in its decision making by analysis of the information provided by Transpower undertaken by its staff and a number of advisors.

Overview of HVDC decision

The document gives a brief overview of the HVDC decision.

Public conference

On 31 July 2008, the Electricity Commission published a notice of intention to approve the investment described in Transpower's HVDC Grid Upgrade Proposal submitted to the Electricity Commission on 2 May 2008.

Subsequently, the Commission received a request for a public conference under rule 15.2 of section III of part F of the Electricity Governance Rules 2003 and agreed to hold a public conference. The purpose of the public conference was to provide a final opportunity for comment on the proposed investment.

The Commission invited parties to register their interest in attending the HVDC Grid Upgrade Investment Proposal conference.

Call for submissions

In order to make the public conference process as transparent and efficient as possible, the Commission invited interested parties (whether intending to present at the conference or not) to provide a written submission in order to assist the Commission in making its final decision.

As part of its preparation for the public conference, the Commission invited submissions on the Commission's decision to approve the Proposal.

Public conference: presentations and Transpower's response to submissions

The following presentations were made at the 22nd of September 2008 public conference regarding the Commission's notice of intention to approve the HVDC Grid Upgrade Proposal.

In addition to Transpower's presentation, the Commission also received Transpower's response to submissions.

HVDC Grid Upgrade Investment Proposal - Final Decision

On 31 July 2008, the Commission issued a notice of it's intention to approve Transpower's HVDC Grid Upgrade Investment Proposal (HVDC Proposal) in accordance with rule 15.1 of the Electricity Governance Rules 2003 (Rules).

A public conference was held in Wellington on 22 September 2008. The purpose of the public conference was to provide affected parties with a final opportunity to comment on the Proposal.

Following its consideration of submissions made in conjunction with the public conference, on 25 September 2008 the Commission decided to confirm its decision to approve the Proposal and has published its final reasons for decision document.

This page is related to: Transmission.