What we do

We provide the infrastructure and market systems that connects electricity generators to major electricity users and distribution networks that deliver electricity to homes and businesses around the country (we don't own, generate or sell electricity)


There are two parts of our business: National Grid owner (looking after the assets that keep the electricity flowing) and System Operator (managing how electricity gets from the point of generation to homes and businesses in real-time and in the future).

National Grid owner

Our National Grid Operating Centres (NGOC) manage the flow of electricity across our high-voltage national electricity transmission grid. Our transmission network consists of 170 substations, 25,000 transmission towers, and more than 11,000 kilometres of lines that run the length and breadth of the country across public and privately-held land. These lines and substations transport bulk electricity (up to 220,000 volts) from where it is generated to cities, towns and some major industrial users. We charge a fee for the use of the transmission network and because we are a natural monopoly these charges are regulated by the Commerce Commission. If you check your household power bill, you’ll find transmission charges comprise around 9% of your bill. More on our Grid.

System Operator

We are also contracted by the Electricity Authority to operate the wholesale electricity market through which generators sell electricity to retailers who then supply consumers. As part of our role, we ensure supply (provided by generators) matches demand (by electricity users). This is done in real time – 24 hours a day, 365 days of the year via our National Coordination Centre (NCC). As System Operator we are also responsible for ensuring New Zealand’s electricity system is reliable, competitive, and innovative and we play an integral role in the planning of New Zealand’s electricity future. More on our System Operator.

Our history

We became a State-owned Enterprise in 1994 but we've been the backbone to New Zealand's economic and social well-being for more than 100 years. We are proud of our history and support voluntary organisation Grid Heritage to build and maintain its collection of New Zealand’s transmission archives. We have also partnered with Heritage New Zealand Pouhere Taonga and local iwi to produce a series of short videos highlighting the importance of protecting Aotearoa’s archaeological history.  




Our future

Transpower continues to be a central figure in planning for and empowering New Zealand’s energy future. Much of New Zealand’s electricity is generated from renewable energy sources (hydro and increasingly wind and solar) that exist in remote areas. We ensure that electricity gets to where it is needed through the National Grid.

With demand increasing for reliable electricity across the country, we must ensure our assets (including towers, lines, substations) are resilient and robust. We’re investing in more assets and greater deployment of technology in our assets and systems to future proof the National Grid. Our Whakamana i Te Mauri Hiko work and our bi-annual monitoring reports outline how New Zealand is progressing towards developing the transmission system of the future.

Read more about Our Strategy.

Read the latest Whakamana i te Mauri Hiko monitoring report.

Read the latest Transmission Planning Report.

Read our Investment Approvals Process.