Vandals have shut down the Tararua wind farm, bringing more than 30 turbines to a halt and costing TrustPower at least $200,000.
Thieves broke into the site’s transformer yard before 1am yesterday, cutting up copper earthing wire in an attempt to steal it, and drained oil from two transformers into catchment reservoirs underneath.
The turbines were still not spinning this morning and at a cost to the company of up to $7000 for each hour of lost operation, the bill could blow out even further.
Ashhurst police would not disclose any details of the break-in as inquiries are under way. The smaller Te Rere Hau wind farm is powered by the Tararua transformer and was also shut down.
TrustPower spokesman Graeme Purches said the cost of repairing the damage is “at this stage unknown”, but the loss of power to the grid could be substantial.
“The farm could be off air for a day, or it could be out for a week. Our general equation in terms of power lost is one megawatt hour is worth about $80,” Mr Purches said.
Tararua wind farm has the capacity to feed more than 93MW of power into the national grid, and its 31 turbines can produce up to 3MW of power each. This could mean a loss for TrustPower of more than $7000 an hour for every hour the farm is not working.
Te Rere Hau wind farm produces up to 48.5MW of power.
The outage affected 31 v90 turbines, but didn’t affect the smaller v47 versions. The disruption was large enough to cause a “frequency disturbance” in the national grid, Mr Purches said the damage won’t affect power to people’s homes.
“It’s a nuisance for us more than anything. These people put themselves in life-threatening danger and caused thousands of dollars worth of damage for a few hundred dollars worth of wire, which they didn’t even manage to make off with.”
Mr Purches said while some parts of the site have security cameras, the transformer yard didn’t, and this was being reviewed.
“Because of the serious danger of entering one of these areas, it’s not normally a place you need security cameras on.
“You’d have to be a complete bloody lunatic to go near one, but we are reviewing this regardless.”
The transformers, which hold thousands of litres of oil each, have protection switches that disconnect if the oil gets below a certain level. It is believed that when the oil caps were removed, the safety device kicked in and caused the power outage.
TrustPower said both farms can run on just one transformer. The company was hoping to resolve the issue today.