Transmission Lines
Transmission lines are the arteries of New Zealand’s National Grid, owned and operated by Transpower. Transmission lines take power from the generators to substations where it is supplied to local distribution companies and large industrial consumers.
Transpower owns and operates 12,175 km of high-voltage transmission lines. Except for the high-voltage direct current (HVDC) link across Cook Strait, all transmission lines carry at least one alternating current (AC) circuit, with a minimum of one conductor per phase. There are three phases per AC circuit.
The core of the National Grid is the 220 kV network in each island and the HVDC link between them. The 220 kV lines connect the largest power stations with the main load centres. Provincial centres and smaller power stations are connected by transmission lines operating at 110 kV, 66 kV and 50 kV. Transpower also has some local lines operating at 33 kV and 11 kV.
Selection of Towers
Transpower’s lines are made up of one or two circuits carried on steel towers (or pylons), or wood or concrete poles. These drawings show the standard configurations and components of the different transmission lines.
Are there transmission lines near you?
If you have a transmission line on your property or live close to a line, you should read our Landowners and Occupiers Booklet for detailed information about safety around the lines and your rights and obligations.
Safety Information
Transpower maintains its transmission lines to a high standard of safety and reliability. As long as lines are treated with caution, they are not dangerous to the public. To see how to be safe around transmission lines, check out our Safety section.
Emergency Number
If you see anything wrong with a Transpower line, or someone in danger around a line, phone our emergency 24-hour hotline 0800 THE GRID immediately.