Te kōtuitui hiko o Tāmaki Makaurau

Auckland's electricity network

A secure and reliable electricity supply is essential to Auckland's success.

There are three elements of a secure and reliable electricity supply:

generation
transmission
distribution.

Auckland relies on other parts of the country for most of its electricity generation and supply. Generation sources in the central North Island and South Island are predominantly renewable hydro, wind and geothermal. They provide 95 per cent of Auckland and Northland’s peak electricity demand [see Note 1].

Transpower’s transmission network traverses Auckland and supplies electricity to Northland. As the network crosses Auckland, electricity is transferred to local distribution lines via a series of exit points, including substations at Ōtāhuhu, Penrose and Mt Roskill. Local distribution companies deliver electricity to homes and businesses. In Auckland, Vector and Counties Power have the responsibility of distributing electricity locally.

Since 2010, Transpower has made substantial improvements to the transmission network. This investment means the core network is now in place, providing adequate capacity beyond 2040. Ongoing maintenance projects will ensure the reliability of the network continues over the next 30 years.

Future demand for electricity

Auckland's continued growth is reflected in projected increases in the region's electricity demand.

Auckland’s population growth and the impact of new technologies create a degree of uncertainty about future electricity consumption. However, it is anticipated that Auckland’s electricity demand will remain at least as high as it is now with increases of about one per cent per year over time [see Note 2].

New and emerging technologies will mean the electricity network will operate differently in the future. This may provide an opportunity to defer future investments [see Note 3]. For example, battery technology is continuing to develop and, in time, will impact significantly on the network. In the long term, it is anticipated that battery or other storage technologies will cover short-term imbalances in supply and demand and smooth out daily peaks.

Energy efficiency will also continue to play its part in reducing overall electricity demand in a variety of ways.

These include:

industry improvements
new houses being built
retrofitting existing housing stock
continued evolution of energy efficient products [see Note 4].

Many new technologies are expected to reduce consumption. This may be partially offset by the uptake of electric vehicles. This uptake could be rapid due to associated benefits such as emission reductions and lower running costs.

In future, it is expected that electric vehicle batteries could have capability to be part of a battery network. This would provide services when the vehicle is plugged in to charge overnight.