Transpower says electricity looking tight on Friday, calls for more generation

Tuesday, 9 August 2022

Weather forecasts have prompted Transpower to put out a call to generators ahead of Friday morning’s peak.

Transpower has called on power companies to fire-up more generation on Friday after cautioning that it could only have a small buffer to cope with unexpected outages during what may be record morning peak demand.

The state-owned enterprise issued a “customer advice notice” to power companies on Tuesday afternoon asking them to offer more electricity into the market between 7.30am and 9am on Friday and to make sure their forecasts of what they expect to generate during that time are accurate.

General manager of operations Stephen Jay said power demand could hit a new record on Friday morning as the cold snap moved north.

Current forecasts were also for little wind on Friday morning, he said.

* Transpower says grid emergency over, lights should stay on tonight

* Transpower: Power cut risk has passed

Transpower operations manager Stephen Jay said it was not anticipating any impact on electricity supply and the call for more generation was “the system working as intended”.

“To be clear, we are not anticipating any impact on electricity supply on Friday morning,” Jay said.

But he said that if power demand reached predicted levels and the wind forecast was accurate, then without action from generators there would be a smaller buffer than it aimed to maintain to ensure the stability of the grid.

Morning demand commonly peaks in winter at about 6500MW and Transpower aims to keep at least 200MW of generation in reserve to cope with contingencies, such as power plant outages.

“With the cold snap worsening and moving north over the country to higher population centres, we are now predicting that Friday morning could potentially see a record morning peak,” Jay said.

“We have also been consulting closely with the MetService, which is forecasting very little wind on Friday morning, which would mean the amount of electricity generated from wind would be much smaller than expected.”

Transpower’s notice was “an example of the system working as intended to ensure that enough generation is offered”, he said.

Jay expected demand for electricity would fall off again on Friday evening and across the weekend “in line with typical demand patterns”.

The notice from Transpower falls short of a warning or emergency notice, which it would only issue closer to the time if supplies remained tight.

Transpower last issued a customer advice notice in early July when generation was also looking tight.

In June, it issued a rare grid emergency notice after a mechanical failure at Contact’s Stratford power station, a fan failure which halved the output from one of the turbines at the Huntly Power Station and a sudden drop in wind speeds combined to leave generation 315MW lower than expected.

In both cases, power cuts were avoided.