Grid needs rebuild says Genesis Energy head

New Zealand has much work ahead to rebuild its high-voltage grid to meet future demand for electricity, Genesis Energy head Murray Jackson says.

He told NGC Holdings' winter lecture series in Wellington that among the factors to be considered were the capacity of the transmission system to deliver electricity long-term.

"The upgrade of the New Zealand high-voltage grid will bring a number of issues and opportunities which need to be debated and resolved without delay," Jackson said.

Stability and security of the supply were key elements.

"The risk of extremes of weather is with us and building transmission and distribution assets to meet these extremes is reaching a stage of urgency.

"These and many more refinements to the market will occupy the mind of the regulator in the coming years ...

"However, more significant in my mind is the immediate need to get focused on the replacement and, where necessary, undergrounding of ageing transmission and distribution assets."

Jackson cited Auckland's electricity infrastructure as an example.

"Security of supply into Auckland will require significant investment if a second high-voltage switchyard away from the 50-year-old Otahuhu switchyard is to proceed."

Developing a second source of supply to Auckland and the upper North Island was in line with meeting essential service obligations that large communities had come to expect.

A tunnel from the Bombay Hills to Penrose, though expensive, would satisfy the city's environmental and residential development needs for 50 years, he said.

The alternatives, such as increasing voltage on existing pylons, were impractical.

- NZPA