Transpower plans Waikato electricity network investment as demand grows

14 May 2024

Cows in field with transmission line in background

As demand for electricity grows in the Waikato, Transpower is considering options to invest in the regional transmission network to ensure the power supply remains reliable. 

John Clarke, Executive General Manager Grid Development said Transpower has identified Waikato as an area where electricity use is growing, the population is growing, and investment is needed to keep power flowing well. 

“We are seeing a ‘pressure point’ starting to emerge where the main Transpower grid connects to our regional electricity network at the Hamilton substation. So, we are opening the conversation about what the Waikato region will need as we look ahead. We are looking for feedback to help us decide what options are feasible and what will work well for the electricity network, communities and businesses in this area,” Mr Clarke said. 

The growing use of electricity in the Waikato reflects its growing population, new industrial developments and the electrification of transport and industrial processes. Businesses and households are switching to electricity, which is over 80% renewable, instead of using coal, gas, petrol or diesel to power their activities. By 2030, the electricity use in Waikato's regional network is forecast to be around 18% higher than it is currently, at peak times. 

“In our long-list document, we’ve outlined different options to keep the electricity supply in the Waikato both reliable and resilient as demand grows. Some of these involve investment in new transmission infrastructure, while others consider solutions such as batteries or reducing demand,” Mr Clarke said. 

The part of the network under increasing pressure is the transformers between the 110 kV regional and 220 kV main grid lines at the Hamilton substation. 

Mr Clarke said while one option is to replace and upsize the existing transformers, there are also other options that could add more resilience into the network at the same time as increasing capacity, providing additional benefits to the community. 

“To add resilience and more capacity, a new connection between the 220 kV and 110 kV lines at a different location is also a possibility, and one we’d like feedback on,” Mr Clarke said. 

Other options in the long-list include reducing demand at peak times or adding more electricity locally into the 110 kV network through batteries or new electricity generation. 

The long-list consultation document details the need for investment and asks for feedback on investment options and the criteria that will be used to refine the options to a shortlist. A shortlist consultation document will be published in late 2024 and will also include more detailed costs. 

The long-list consultation documents can be downloaded from our website.

Consultation on the long-list is open until Tuesday 25 June 2024 and feedback can be emailed to [email protected].  



The 220 kV lines to the east of Hamilton bring electricity generated in other parts of New Zealand into the region and connect to the 110 kV network at the Hamilton substation. Electricity generated from two power stations on the Waikato River enters directly into the 110 kV network. The 110 kV network then distributes electricity to homes and businesses in parts of Hamilton city, the surrounding towns and farms south of Hamilton, and communities north towards the Thames Valley. 

By 2030, the electricity use in Waikato's regional 110 kV network is forecast to be around 400 MW at peak times, up from 337 MW currently. 


For further information, please contact: 

Rachael Drummond, Senior Corporate Communications Advisor, 021 394 803.