16 May 2024

Grid rethink needed for Waikato power - Transpower

8:56 pm on 16 May 2024
Dry land

Some parts of Waikato's power grid will not be able to meet peak needs by 2035, and upgrades are needed, Transpower says. Photo: RNZ / Rebekah Parsons-King

Power grid capacity in Waikato is approaching its limit and new ways to add resilience to the network are needed, Transpower says.

The company's executive general manager of grid development John Clarke said population and electricity use were growing in Waikato and investment was needed to keep power flowing well.

According to the latest data from Stats NZ, Hamilton is now New Zealand's fastest-growing city.

"We are seeing a 'pressure point' starting to emerge where the main Transpower grid connects to our regional electricity network at the Hamilton substation," Clarke said.

The national grid owner is seeking feedback on a long list of ideas, including investment in new transmission infrastructure, battery storage, and reducing demand to address the issue.

"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," Clarke said.

Power transmission in the Waikato region is complex, with both 220kV and 110kV circuits providing connections to other regions and the national grid, and the 220kV and 110kV circuits linked by interconnecting transformers at Hamilton.

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, Transpower said.

By 2035, during peak loads and with minimum 110 kV generation output, the continuous capacity of the interconnecting transformers will be exceeded.

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," Clarke said.

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