Transpower New Zealand Limited

Transpower New Zealand Limited

Type	State-owned enterprise
Industry	Electricity Transmission
Founded	1994
Headquarters	Wellington, New Zealand
Key people	Mark Verbiest, Chairman Patrick Strange, Chief Executive
Revenue	NZ$737,200,000
Operating income	NZ$458,000,000
Profit	NZ$126,300,000
Total assets	NZ$4,170,600,000
Total equity	NZ$1,533,500,000
Employees	661 (2011)
Website	www.transpower.co.nz

Transpower New Zealand Limited (TPNZ) is the state-owned enterprise responsible for electric power transmission in New Zealand. Transpower performs two major functions in the New Zealand Electricity Market. As the owner of the National Grid it provides the infrastructure of electric power transmission that allows consumers to have access to generation from a wide range of sources, and enables competition in the wholesale electricity market. As System Operator it manages the real-time operation of the grid and the physical operation of the New Zealand Electricity Market.

Transpower was formed as a wholly owned subsidiary of the Electricity Corporation of New Zealand (ECNZ) in 1987. In 1994 it was separated from ECNZ and corporatised to become a state-owned enterprise with its own board of directors and Ministerial shareholders. The shareholders are the Minister of Finance and the Minister of State-Owned Enterprises. The New Zealand Treasury Crown Ownership Monitoring Unit monitors the performance of Transpower on behalf of the shareholding Ministers.

The role of the National Grid

Main article: National Grid (New Zealand)

The New Zealand national grid provides the means of transporting bulk electricity from where it is generated (by companies like Meridian Energy and Mighty River Power) to cities, towns and some major industrial users like the aluminium smelter at Tiwai Point. Most of the electricity from the national grid is delivered to New Zealand’s homes and businesses by electricity distribution companies like Vector and Orion. A few large industrial users are directly connected to the national grid. A network of 220 kV transmission lines forms the core grid in the North and South Islands, and this is supplemented by 110 kV, 66 kV and 50 kV transmission lines, which connect the core grid to smaller load centres. The two islands are connected via the HVDC link which is New Zealand's only high voltage direct current (HVDC) system.

The revenue that Transpower receives for the provision of the transmission service is regulated by the Commerce Commission. The type of regulation is individual price-quality regulation, and came into 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 role of the System Operator

The role of the System Operator is to manage the security of the power system in real time and co-ordinate the supply of and demand for electricity, in a manner that avoids fluctuations in frequency or interruptions of supply. The System Operator is required to maintain a continuous (second-by-second) balance between electricity supply from power stations and demand from consumers, and also ensure the provision of reserves that will allow for sudden contingencies. The System Operator achieves this by determining the optimal combination of generating stations and reserve providers for each market trading period, instructing generators when and how much electricity to generate, and managing any contingent events that cause the balance between supply and demand to be disrupted. System Operations staff undertake this work using sophisticated energy modelling and communications systems. In addition to its roles of real-time dispatch of generation and managing security, the System Operator also carries out investigations and planning to ensure that supply can meet demand and system security can be maintained during future trading periods. Examples of planning work may include co-ordinating generator and transmission outages, facilitating commissioning of new generating plant and procuring ancillary services to support power system operation.

The System Operator service is provided and funded under an agreement with the Electricity Authority.

See also

• National Grid (New Zealand)
• Electricity sector in New Zealand
• Electric power transmission

External links

• Transpower

Further reading

• Reilly, Helen (2008). Connecting the Country – New Zealand’s National Grid 1886 - 2007. Wellington: Steele Roberts. pp. 376 pages.. ISBN 978-1-877448-40-9.