Wellington Electricity

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Wellington Electricity
IndustryElectricity distribution
PredecessorVector Limited
United Networks
Key people
Greg Skelton (CEO)
RevenueNZ$151,918,000 [1]
Total assetsNZ$527,446,000[1]

Wellington Electricity Lines Limited (Wellington Electricity) is an electricity distribution company, based in Wellington, New Zealand.

Wellington Electricity supplies electricity to approximately 400,000 consumers through over 164,500 installation connection points (ICPs) in its network that covers the Wellington city, Porirua and the Hutt Valley regions. [2]


Cheung Kong Infrastructure Holdings Limited and Power Assets Holdings Limited together own 100 per cent of Wellington Electricity, with both companies being members of the Cheung Kong group of companies and listed on the Hong Kong Stock Exchange (HKEx). [3]

Distribution network[edit]

An older Wellington Electricity power pole with an 11/0.4 kV pole-mounted distribution transformer in Paparangi, 2006.
The Hataitai zone substation

Wellington Electricity uses a 33 kV sub-transmission network, with 11 kV high-voltage distribution and 230/400 V low-voltage distribution. The network comprises a high percentage of underground cabling, with 66% of the sub-transmission circuits being cabled. Wellington Electricity also owns and operates several rectifier stations and a 53 km network of DC cables in central Wellington, used to supply the trolleybus system.

The majority of electricity used in Wellington is taken from the national grid at Transpower substations located at Upper Hutt (Birchville), Haywards, Melling, Gracefield, Pauatahanui, Takapu Road (to the east of Linden), Kaiwharawhara, Wilton and Central Park (Mount Cook). The network also receives up to 12 MW of electricity from power generating facilities connected to the distribution network, including two landfill gas stations at Silverstream and Happy Valley, a gas fired cogeneration facility at Wellington Hospital, and a single wind turbine in Brooklyn.

A major project was completed in 2012 to replace 33 kV underground cables that supply part of the Wellington Central Business district. New cables were installed from Wilton to Moore Street in Thorndon. [4]

Network statistics[edit]

Wellington Electricity Lines Limited network statistics as of 31 March 2016[5]
Parameter Value
Total system length 4,697 km
33 kV 196 km
11 kV 1,755 km
Low voltage 2,747 km
Street lighting 386 km
Customer connections 166,591
System maximum demand 557 MW
System energy delivered 2,468 GWh

Network performance[edit]

The Wellington Electricity 2016 Information Disclosure reported the performance of the network for the 2015/16 year as follows:[5]

Parameter Actual Normalised
System Average Interruption Duration Index (SAIDI) 32.50 mins 32.41 mins
System Average Interruption Frequency Index (SAIFI) 0.59 0.55

This level of network performance means that average consumer typically experiences a power outage lasting 55 minutes once every 20 months. However, Wellington is subject to severe storm events and high wind gusts that can cause extensive interruptions for some consumers. Normalised figures are exclusive of major weather events and outages.


The ownership of Wellington Electricity has changed significantly since the early 1990s. At the start of the 90s, the Wellington City Council Municipal Electricity Department (MED) and the Hutt Valley Electric Power Board (HVEPB) merged their electricity assets. In 1992, the passing of the Energy Companies Act required that the various franchised electricity distribution and retailing organisations then operating in New Zealand become commercial power companies with a responsibility to operate as a successful business. Two new companies were formed, Capital Power and Energy Direct respectively.

In 1996, the Canadian owned power company TransAlta acquired both companies to form a consolidated Wellington electricity distribution network business. The Electricity Industry Reform Act was passed in 1998, and this required that all electricity companies be split into either the lines (network) business or the supply business (generating and/or selling electricity) by 1 April 1999. Ownership of the lines network was passed to United Networks in 1998, which Vector acquired in 2003.[2]

In July 2008, the network was purchased by Cheung Kong Infrastructure Holdings Limited and Hong Kong Electric Holdings Limited to create Wellington Electricity.[6] Hong Kong Electric Holdings Limited changed its name on 16 February 2011 to Power Assets Holdings Limited.

See also[edit]


  1. ^ a b c "Electricity Information Disclosure Summary Database 20008-2011". Commerce Commission. Retrieved 14 July 2012.
  2. ^ a b "Wellington Electricity - 10 Year Asset Management Plan 1 April 2012 – 31 March 2022" (PDF). Wellington Electricity. Retrieved 13 July 2012.
  3. ^ "Infrastructure Investment In New Zealand". Cheung Kong Infrastructure Holdings Limited. Retrieved 14 July 2012.
  4. ^ "CBD/Wilton 33 kV Cable Replacement Project" (PDF). Wellington Electricity. Retrieved 13 July 2012.
  5. ^ a b "EDB Information Disclosure - Wellington Electricity Lines Limited - year ending 31 March 2016". 31 August 2016. Retrieved 21 February 2017.
  6. ^ "Chinese pay $785m for Wellington network". Stuff.co.nz. 28 April 2008. Retrieved 13 July 2012.

External links[edit]