Transpower Completes Temporary Tower Replacement To Restore Further Northland Electricity Capacity

Transpower has restored further electricity supply into Northland this evening after erecting a temporary tower and transferring one of its two 220 kV transmission lines (circuits) across.

The work restores more electricity supply capacity into the affected parts of New Zealand from Warkworth north after a transmission tower on farmland near Glorit fell at 11am Thursday morning.

Transpower Chief Executive Alison Andrew apologised to impacted areas for the disruption to supply.

“What happened was unacceptable and we apologise to all those that have been impacted by the outage caused by the fallen tower,” she said.

“It is never easy to be without electricity and we know that Northland has been through a lot in recent years. We also know it’s a resilient part of New Zealand and we’d like to extend our thanks to local communities and leaders, Civil Defence and our lines company partners and local generators for their support and assistance.”

Supply was cut off at 11am Thursday while routine maintenance was under way. Working with local lines company partners Northpower, Top Energy and Vector, Transpower was able to begin restoring power through its parallel 110 kV network from around midday the same day.

Most of Northland was connected later that afternoon, but supply was limited and a number of households remained without power for a time. Some major industrial users stayed shut to ensure available supply went further.

Transpower Executive General Manager Grid Delivery Mark Ryall said design engineers and service providers worked at incredible speed to get the work done ahead of demand ramping up again from Monday morning, which he said would have put pressure on the electricity supply that Transpower had re-routed through its 110 kV network.

“Our internal team and our service providers worked around the clock to design, and deliver the solution within significantly compressed timeframes” Mr Ryall said. “With electricity supply into Northland at reduced levels, it was critical we got this tower up and supply restored through our 220 kV network over the weekend.

“Our design engineers worked through the night Thursday to plan the work and once we had necessary equipment in place Friday our crews began the complex and challenging work of putting up the tower and transferring the transmission line across.”

Work was completed and the circuit re-livened shortly after 2pm. Mr Ryall expressed his thanks to everyone working on the replacement tower along with local lines companies Northpower, Top Energy and Vector and local generators Ngawha, Manawa and KTA Solar for their assistance in managing the situation and getting to this point.

“We’d also like to thank the landowner for facilitating access to the site, especially given the extent of the civil works required,” he said. “And the local Glorit community has been fantastic with their support for our team on the ground.”

Mr Ryall noted that while transmission capacity has been restored, full security of supply will not be restored until the second 220 kV circuit is returned to service. Additional temporary structures need to be installed and the remaining circuit transferred to them. This circuit is under the fallen tower and the work is more complex than for the first circuit.

“We will be doing everything we can to get this completed as quickly as possible and hopefully before Friday,” Mr Ryall said.

“This means there is increased risk of short power cuts if faults happen to one of our three circuits currently supplying Northland but, depending on the cause, any disruption is likely to be short lived.” 

Investigation underway

Ms Andrew said that there has rightfully been a lot of interest in what caused the tower to fall and that Transpower would turn its full attention to that now that supply into Northland has been restored.

“Something has gone terribly wrong for a tower to fall over, and we need to make sure it doesn’t happen again,” she said.

“From the beginning we have been committed to doing a thorough investigation once power is restored. We have appointed an external party to lead that work and we will announce more details of that in coming days.

“But as we have said all along, it was unhelpful to speculate on the cause while we were focused on restoring electricity supply as quickly as possible for the people of Northland. That had to be our priority. It is complex and challenging work, we were moving at pace, and distractions would not have helped.

“We have been gathering information about what happened in parallel, but it is critical that we take a measured and informed approach to our investigation.”

The Electricity Authority announced Friday that it is also conducting a review after being instructed by the Minister for Energy.

“We welcome the review and will work closely with the Authority to ensure everyone understands what happened and we can take the lessons to prevent something like this happening again,” Ms Andrew said.

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