Wairarapa narrowly avoided widespread power cuts Friday morning just as Masterton was suffering through a chilling low of zero degrees Celsius.
Transpower issued a grid emergency notice on Friday for the North Island, including Wairarapa, warning of possible disconnections across the island.
It said the warning was because of a fault on one of the two Cook Strait cables, which brought electricity up from the South Island.
Transpower first issued a warning notice at 5.37am. It said there was a risk of insufficient generation and reserves to meet North Island demand. A second notice was issued at 7.15am, warning there was still a risk of insufficient generation to meet demand in the North Island.
Transpower said some power was still flowing across the cable, but a second fault could suddenly stop the flow of electricity.
It said it worked with lines companies to manage controllable loads such as hot water systems.
The notice period ended by 8am.
Yesterday’s grid emergency notice was the second of the year, with Wairarapa and the rest of New Zealand narrowly missing power cuts on June 23.
Wairarapa electricity provider Powerco said it did not need to disconnect any of its customers yesterday. However, Powerco’s website showed an outage to 99 Solway customers from 8.36am, with an estimated restoration time of 3.45pm.
Powerco said the outage was planned and unrelated to the emergency notice.
“This is a planned outage, required so that crews can replace poles in the area.”
An additional 12 outages are planned for Solway between tomorrow and November 1 for maintenance, including tree trimming, replacing poles, and replacing transformers.
Transpower’s general manager of operations Dr Stephen Jay said that the system operator had worked with electricity lines companies and large industrial customers connected directly to the grid to reduce demand.
He said New Zealanders would not notice any impact because lines companies would mostly be turning off controllable loads like hot water systems.
“Hot water systems are switched on and off regularly during winter.”
Jay said that if the removal of the controllable load was not enough to balance the power system, then Transpower would need to ask for additional demand to be cut until the power grid was secure, which could result in disconnections.
He asked North Island residents to be mindful of their electricity use yesterday morning to help get through the situation and avoid power cuts.
“It is an unseasonable cold day so please stay warm by continuing to heat the rooms you are using but consider turning down the thermostat a degree or two.”
Transpower chief executive Alison Andrew said lines companies knew what was expected of them when the notice was issued and moved quickly to manage controllable load and reduce demand.
Andrew said the cable was fully operational by midday and plenty of power was available for the North Island.
Freezing temperatures and the risk of no power
