Northland customers largely unscathed from nationwide power shortage

Thanks to generation from Ngawha geothermal power station as well as diesel gensets, the Far North didn't lose any power. Photo / Supplied

Most Northlanders have remained unaffected after a nationwide power shortage left some Kiwis without power on Monday night.

A record-breaking demand for power on Monday forced national electricity authority Transpower to turn off power to households across the country during peak hours between 6pm and 9pm.

"Unfortunately, there was not enough generation to meet demand," Stephen Jay, general manager operations, said.

"As a result, Transpower had to ask all the local lines companies and large industrial users to reduce demand to help keep the system in balance."

Northland lines company Northpower, which is largely maintaining the Whangārei and Kaipara network, said some customers in Dargaville had been affected.

"Northpower responded by utilising our hot water control system as well as a short outage to around 900 customers in the Dargaville area," Rachel Wansbone, customer experience manager, said.

Turning off hot water is an effective method for lines companies to take pressure off the network. Customers only lose hot water if their hot water cylinder runs low.

Wansbone said if this happened again Northpower's response would be similar:

"First turning to hot water control to decrease load and then looking at outages where we can affect as few customers as possible for as little duration as possible."

In the Far North, lines company Top Energy kept the power running for all its customers thanks to local power generation.

"Power was maintained through back-up generation from diesel gensets in Taipa and Kaitaia and the increased generation from Ngawha geothermal power station," Philippa White, spokeswoman for Top Energy, said.

"We did not need to turn power off to any of our customers."

Due to the colder weather there is more demand on the transmission and distribution electricity networks at peak times as people turn on heaters, cook meals, run hot baths.

Peak demand in New Zealand usually sits around 6500MW-6700MW. On Monday night the country hit 7100 MW.

"Top Energy is prepared for another cold night and back-up generation is available, should it be required," White said.

"However, we ask that our customers manage their electricity use during peak evening times to help reduce the load on the network.

"All medically dependent customers are advised to action their back-up plans or contact their nearest hospital if required."

Energy Minister Megan Woods said the events from Monday night were not acceptable and Prime Minister Jacinda Ardern wants to find out why Kiwis were without power on one of the coldest nights of the year.

"New Zealanders have a right to expect that on a cold night the power will stay on and they'll be able to keep the lights on and heat themselves," Woods said.