Electricity transmission

Transpower is the sole owner and operator of the New Zealand national electricity transmission grid.

Transpower is regulated under Part 4 of the Commerce Act 1986 by way of individual price-quality regulation. This took effect on 1 April 2011. The individual price-quality path governs Transpower's revenues for each pricing year, with the paths being reset either every four or five years. The individual price-quality path was reset for the 2015-2020 regulatory period on 1 April 2015.

Transpower input methodologies support the individual price-quality regulation.

Under subpart 9 of the Part 4 of the Commerce Act, Transpower is also subject to information disclosure regulation.

Current documents that apply to Transpower and links to other Transpower pages

Transpower web pages

Determinations, decisions and current documents

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Transpower's price-quality regulation from 2015 to 2020

Transpower Central Park/Wilton reconductoring listed project - draft decision

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Transpower individual price-quality path amendment determination 2016 (MAR update November 2016) – 31 October 2016

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Companion paper to the update of Transpowers maximum allowable revenues 2015 – 5 November 2015


Companion paper to final Transpower Individual Price-Quality Path Determination

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Setting Transpower’s individual price-quality path for 2015-2020 – final decisions and reasons


Transpower input methodologies

Capex IM Review – Decisions and Reasons – 29 March 2018

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Transpower Input Methodologies determination as at 12 February 2015

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  Reasons paper for amendments to Transpower input methodologies – August 2014  


Transpower Input Methodologies reasons paper December 2010

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Transpower capital expenditure Input Methodology determination as at 5 February 2015

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  Capex IM final reasons paper – 31 January 2012 Read more

Cost of capital

Cost of capital determination for electricity distribution businesses default price-quality paths and Transpowers individual price-quality path – 31 October 2014

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Price-Path Compliance

Update to the 2014/15 forecast MAR (October 2013)



Annual compliance monitoring statement 2013/14 – April 2015


Transpower information disclosure

Transpower information disclosure determination – consolidated 3 April 2018

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Transpower information disclosure determination – 28 February 2014


Transpower information disclosure determination and reasons paper – 28 February 2014


Major capital proposal

Final decision – amending the allowance and outputs for the North Island Grid Upgrade Project – 6 August 2015



Previous decisions

Transpower individual price-quality regulation

Opex capex review 2012/2013 to 2014/15

Administrative settlement

Decision on instantaneous reserves

Review of non part F expenditure proposal under the administrative settlement

Transpower information disclosure

Transpower is subject to individual price-quality regulation and information disclosure regulation.

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Transpower price-path compliance

Compliance with the price-quality path is achieved if the forecast revenues Transpower uses to set charges for a pricing year do not exceed the forecast maximum allowance revenue (MAR).

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Transpower major capital proposal

Transpower uses a major capital proposal to seek regulatory approval for a major capital investment in the national grid or the high-voltage electricity transmission network.

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Transpower individual price-quality regulation

The requirement to develop and apply a new type of regulation to Transpower was one of the key changes to the Commission's regulatory responsibilities under the Commerce Amendment Act 2008.   Individual price-quality regulation was implemented on 1 April 2011.

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