Just a few weeks earlier, solar generation exceeded thermal generation for the first time, and Northland played a leading role.
The region’s growing renewable energy market and challenges are laid bare in an economic report from Northland Regional Council economist Darryl Jones and economic adviser Codie McIntyre.
It paints a picture of scope to expand renewable energy resources so that Northland can generate all its energy from renewable sources and export excess power to Auckland.
It also says poor power infrastructure is holding back the renewable revolution.
Meridian Energy’s first grid scale solar farm, under construction at Ruakākā, will span 201 hectares, producing up to 230 GWh annually.
Transpower, the state-owned enterprise that owns, operates and maintains the high-voltage National Electricity Grid, said the transmission network from Auckland to Whangārei had no immediate transmission constraints preventing development and connection of additional renewable generation.
However, Transpower executive general manager grid development Matt Webb said there are constraints in the Far North on Top Energy’s Kaikohe-Kaitāia 110kV line and Transpower’s Kaikohe–Maungatapere 110kV line.
“Northland is a region with significant long-term renewable energy potential. This potential is across the region, and investment and development is happening at pace,” Webb said.
“With regard to the 220kV network from Marsden (Point) to Auckland, there are no immediate transmission constraints preventing the development and connection of additional renewable generation in the region.
“This is because the region north of Whangārei currently imports around 224MW at peak from Auckland via the transmission network. Any new generation in Northland would first offset that existing demand, with only the amount not used locally able to be exported out of the region.”
Meridian’s $186 million battery Energy Storage System (BESS) at Ruakākā, south of Whangārei.
He said Transpower analysis indicates once Northland’s own demand has been met, the existing 220kV transmission network can accommodate several hundred megawatts of additional generation exports to the south before major transmission upgrades would be required.
Further enhancements, including reconductoring a 220kV circuit between Marsden to Auckland, could increase this export capability even further before the existing Auckland–Marsden transmission corridor became a limiting factor.
Only then would major transmission grid upgrades be necessary.
Ngāwhā geothermal plant is the Northland’s largest electricity generator, producing 450 GWh a year
Constraints exist only in the Far North, Webb said.
“We have already installed a Special Protection Scheme (SPS) on the Maungatapere–Kaikohe corridor in December 2025, which provided sufficient capacity for committed generation projects and approximately 40MW of additional export capability,” he said.
“For further significant transmission investment in the Far North, there would need to be additional confirmed generation commitments or clear evidence that planned generation development will exceed existing capacity to avoid these costs being borne by local communities.
“This is because we recover transmission costs from lines companies, generators and major industrial customers connected directly to the grid according to rules set out in the Electricity Authority’s Transmission Pricing Methodology (TPM).
“Under the TPM, the cost of transmission infrastructure has to be recovered from the beneficiaries. In this case, the costs of building additional capacity ahead of firm commitments for new generation would need to be recovered from our local line company partners Northpower and Top Energy and the consumers they serve.”
This is also why Northpower and Top Energy have decided not to move ahead with the Energy Bridge work at this stage, he said.
The Kohirā Solar Farm, just out of Kaitāia, was the largest in the country when it opened with 61,000 solar panels.
“However, we continue to work with Northpower and Top Energy and potential generation investors so that we can carefully phase any additional investment to unlock the region’s renewable generation potential while ensuring Northland communities are not asked to pay now for assets that might benefit renewable energy developers,” Webb said.
A Northland Corporate Group survey by NZEIR last year found the region generated around 540 gigawatt hours (GWh, equal to one billion watt-hours) of renewable power annually, but could expand.
Northland uses about 1200GWh of electricity a year, with over half the region’s power imported from the national grid.