Storm cut 40% of Auckland power network in minutes
Vector says adding resilience far from clear-cut as it plans for city’s future
On the night of April 10 this year, Auckland lost 40 per cent of its power network in just 15 minutes. The storm was unexpected, and is still not regarded as a hurricane in the way other storms of similar ferocity are, when they strike elsewhere in the Pacific.
Executives from the power company Vector reported on the story to a meeting of the Planning Committee of Auckland Council yesterday. Chief executive Simon Mackenzie revealed they now call the storm “Hurricane No Name”.
Chief networks officer Andre Botha said that from 1pm to just before 9pm, winds were gusting at 100-125km/h, which is severe enough to cause damage, but they were confident the network was holding up.
Then at 9pm the wind suddenly became twice as fierce, with gusts up to 215km/h.
“We lost 40 per cent of the network over a 15-minute window,” Botha said. “There were 4000 points of damage.”
Hurricane No Name, which lasted through the night and into the next day, cut power to more than 200,000 Auckland properties, and with many of them the damage on the property itself was too severe for power to be reconnected straight away. Some homes had no power for up to 11 days.
As has been earlier reported, the Insurance Council says more than 13,000 claims were made following the storm.
Botha told the council meeting that it was now engaged in a major exercise
to strengthen the resilience of Auckland’s power network, but the answers were not straightforward.
City growth means the company is “building new network capacity the size of Hamilton every 2.5 years”.
Currently, 55 per cent of the network is underground, and all new lines go underground. Botha said the cost to replace overhead power lines with underground lines in urban Auckland was $3.6 billion. The cost to do the same for the rural parts of the city was another $1.9b.
In a separate statement, Simon Mackenzie said the cost of undergrounding the entire network “could potentially quadruple electricity bills for decades”.
There are some problems with undergrounding. Mackenzie warned that it would mean a write down of assets, which posed “an economically difficult decision” for Vector.
And while buried lines are safer from storm damage, when damage does occur, it is more costly to repair.
Mackenzie suggested that Auckland needs a larger conversation about trees near power lines. Current regulations are that the “cut zone” For video go to nzherald.co.nz should be 1.5 metres around the lines.
“In some jurisdictions the cut zone is 40 metres”, he said.
Councillor Penny Hulse responded by saying she was “not going to use a rude word, but I think Aucklanders face a clusterdrama. We love our trees but do we love our cups of coffee even more?”
Vector yesterday released a discussion paper on resilience that calls for a “more holistic” approach.
In his separate statement, Mackenzie said: “Globally there is a growing awareness and sharper focus on emerging technology to unlock the opportunities of shared resilience that lie ahead.
“Our paper calls for more discussion on how industry, government and consumers can work together to deliver the best possible outcomes for New Zealand.”