Powering a resilient region

The year has been an exceptionally busy one for the team at the region’s lines company.

In March, Eastland Network became part of Clarus (formerly Firstgas Group), one of New Zealand’s largest energy groups. While they have a new name, Firstlight Network, and a new owner, the team’s day to day operations and responsibilities remain the same.

“As a lifeline utility, we’re here to keep the lights on across 12,000 square kilometres in Tairāwhiti and Wairoa,” says Acting Operations Manager Linda Broughton.

While the transition to a new owner has gone smoothly, the Network staff have been faced with an unprecedentedly challenging time as multiple severe weather events hammered the region.

When ex-Cyclone Hale and Cyclone Gabrielle hit, Ms Broughton was Senior Project Manager, and a key part of the team managing internal and external contractors.

“Most of the network stood up well, but we’ve never seen anything like the number, length and severity of the storms,” she says.

“During each of these events, our staff and contractors were working in incredibly tough conditions. Their health and safety, and that of local communities, was our number one priority. Then our focus was on restoring power as quickly as possible given the weather and the many impassable roads, slips and floods.”

Locals will remember that Cyclone Gabrielle initially caused power to go out for the whole region. This was due to damage at Transpower’s Redclyffe substation.

Once the region was reconnected to the national grid, there were still around 4,500 customers without power. A week after the cyclone, there were just under 1,000 customers still off, with generators helping to provide power to isolated communities. Due to the damage to roading and the network, it took more than two weeks to restore supply to the final few isolated customers.

A recently completed infrastructure project helped lessen some of the impacts of Gabrielle.

The suburb of Kaiti and the whole of the East Coast used to be dependent on the one 50kV line from the Gisborne substation, which meant any fault on that line could knock power out to the entire Coast.

“At the Gisborne sub we split Kaiti and the Coast onto two different feeders, and established a second line, so we now run two 50kV lines to Tokomaru Bay,” explains Ms Broughton.

“This means that a fault between Gisborne and Tokomaru Bay won’t affect the rest of the Coast. During Cyclone Gabrielle we were able to bypass much of the major damage and restore power to many Coast communities within a relatively short period of time.”

As 2023 draws to a close, the Firstlight Network team are taking the learnings from the storms and using these to help inform their future plans.

“Regional energy resilience has long been a priority for the Network,” says Ms Broughton. “The all-too-real effects of climate change have brought this into even sharper focus.”

Each year the Network updates its Asset Management Plan (AMP), which details its multi-million dollar annual programme of asset maintenance and upgrades.

“The AMP combines both existing workstreams and also new initiatives as part of our resilience strategy. These will help us better understand and respond to the wind, flooding and geotechnical challenges that are becoming more acute due to climate change.”

Priorities include enhancing vegetation and asset fleet management, increasing levels of security and automation, developing solutions for future electricity demand growth, and supporting the long term energy transformation and decarbonisation of the region.

Trees falling through lines is a major cause of power outages, both in Tairāwhiti and across New Zealand.

During Cyclone Gabriele the single biggest cause of power was damage from ‘out of zone’ vegetation – trees that had not grown close enough to power lines for trimming to be mandatory, but which still fell on lines during the storm. This was the case in Tairāwhiti and, as a review by Electricity Networks Aotearoa concluded, in all the cyclone-hit areas across New Zealand.

“We’ve targeted a 5% reduction in vegetation-related outages each year. Given the significant damage from out of zone trees during major weather events, we’ve increased the emphasis on this in our vegetation management strategy.

“Our intensive work around feeders and sub transmission assets is showing positive results. Our dedicated tree team continues to work with homeowners, farmers, forestry companies and other local stakeholders. And, with the Electricity (Hazards from Trees) Regulations 2003 currently under review, we have submitted feedback and recommendations.”

Post-Hale and Gabrielle, the Network has further accelerated its annual wood pole replacement programme, and is conducting an assessment of all the 110kV towers across the region.

“We’re developing and implementing mitigation plans. For example, we’ve increased the scope of our automation programme to improve feeder security and reliability through additional reclosers and switch automation.

“In Mahia, we’re undertaking a multi-year plan to support expansion and power reliability in the area. A transformer has been purchased as we continue to progress this project.”

Firstlight Network’s engineers and project managers are investigating a range of other upgrades in the medium- to long-term, to increase the amount of energy supply to the region. While the overall supply is more than adequate currently, future growth in demand needs to be considered.

“In Wairoa we’re planning to reconfigure the substation site to increase transformer capacity. This will take place in several stages over the next decade.

“Other potential opportunities include a capacitor bank upgrade at the Gisborne substation and a thermal upgrade of the sub-transmission lines.”

Looking further ahead, the Network team will be focusing on the transition to a low carbon economy. They are preparing for the increasing electrification of transport and heat, and the development of solar and other distributed generation.

“As part of a larger group of energy companies, we have the capital and capabilities to ensure we can invest for the future,” says Ms Broughton.

In the meantime, regional energy resilience remains the focus.

“After a very testing 12 months, we’d like to thank our contractors, the communities of Tairāwhiti and Wairoa, Civil Defence, the councils, and the other local and national organisations who we’ve worked alongside on the recovery effort.

“There are still many challenges facing us all. We’re making sure that Firstlight Network is well prepared to play its part in powering a strong economy and a resilient region.”