What we do

We keep New Zealand's energy flowing by:

  • 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 New Zealand Steel)
  • connecting with smaller lines companies (like Vector) who package and deliver that power to the doorsteps of New Zealand’s homes and businesses
  • managing New Zealand’s power system (as the System Operator) so that electricity is delivered whenever and wherever needed, 24/7.

Generators and lines companies pay us to use our assets, but by the time the power gets to your home or business we make up just a small proportion of your electricity bill – on average around 9%.

Because our transmission network is a natural monopoly, our investments and transmission charges are regulated by the Commerce Commission.

Maintaining our assets

Towers, poles, lines, cables and substations stretching and connecting the length and breadth of the country represent our asset base - known as the National Grid. It includes:

  • 11,238 route km of high voltage transmission line
  • 60 route km of underground and submarine transmission cable
  • 40,674 supporting towers and poles
  • 169 substations
  • 1093 transformers

Some of our assets have economic lives of up to 70 years, so we need to look after them to make sure they last the distance.

Maintaining our assets in good condition avoids having to replace them until it is needed, saving Transpower, the electricity industry and New Zealand consumers unnecessary cost.

We have asset maintenance programmes for every type of asset we own – from circuit breakers to tower foundations.

Managing New Zealand's power system

As System Operator, Transpower manages the power system in real time to ensure energy is flowing to where it is needed: 24 hours a day, 7 days a week.