Nine hours without power on coldest day

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The irony of living in the shadow of New Zealand’s third-largest hydro-electric power station is not lost on the residents of Clyde.

The town’s ‘‘Third World’’ electricity infrastructure failed for about nine hours last Sunday and 1200 homes and businesses lost power.
That left businesses to count the cost and residents shivering in temperatures as low as -9.9degC — the coldest day of winter so far — after the lights went out in and around the Central Otago township from about 7am.

Power was progressively restored from about 3.30pm, too late for most hospitality businesses and the town’s elderly population were left with no means of heating or cooking for much of the day.

Vincent Community Board deputy chairman and Clyde resident Russell Garbutt said the operational transformer at the Clyde Earnscleugh Substation failed and the backup transformer had been relegated to little more than ‘‘scrap metal’’.
‘‘It used to be if there was a failure in the first transformer it switched to the second and all residents would notice was a flicker of the lights.’’
‘‘I’m very angry about the effect on businesses. I’m angry about the effect on the elderly or people using medical equipment, and I’m angry for those people who were just bloody cold.’’

Clyde-based former Aurora professional engineer Steve Tilleyshort, who worked for the company for 17 years, said he had completed the design to switch the substation from 6.6kv to 11kv but Aurora had not gone ahead with the plan, instead adopting a ‘‘she’ll be right’’ attitude.
The 6.6kv system was outmoded, he said.
‘‘It’s a very old system. It’s so old you wouldn’t be able to get parts for it.
‘‘You wouldn’t be able to replace those transformers.’’

The backup transformer had been identified as a risk before it failed and the functional transformer was also ‘‘on shaky ground,’’ MrTilleyshort said.
His understanding of the failings of Clyde’s electricity infrastructure meant he had ended his 50-year career with with a portable generator on stand-by in his retirement, he said.
‘‘I know this won’t be the last time.’’

Former Delta employee Richard Healey said the second transformer failed in 2017 at the age of 58.
‘‘It’s smaller than the existing transformer but a few years ago a switch was installed to allow the two MVA transformers down the road that powered the old gold mine to parallel up with it and provide supply to Clyde, even atpeak load.’’
He could not understand why it had not be used, except to assume power was already being directed elsewhere or it had also been abandoned.
‘‘It’s a bit rich of Aurora to say their plan isinstall the mobile sub in an emergency.
‘‘Steve Tilleyshort was working on a plan toallow that to happen but it required moving the sub to a new site.’’

The mobile substation could be hooked up where it was but would create a significant risk of voltage transfer to the telecom cables in the road nearby — something Mr Tilleyshort was designing for, he said.
Aurora duped the public when trying to justify ‘‘grossly unfair’’ line charges in Central Otago (double those in Dunedin, almost double those of the Wakatipu basin) when it quoted the length of lines in Central Otago divided by the number of consumers, Mr Healey said.
‘‘Hey presto — there is twice the length of line for each customer, so of course the charges should be double.’’

An Aurora Energy spokeswoman apologised to customers, given the extremely cold weather in Clyde, and said the second transformer in the substation was never operational as a backup.
‘‘Our backup for the single transformer on site isthe mobile substation.’’
The mobile substation would remain in Clyde while further maintenance was completed, she said. Affected customers would receive a $50 credit.