Challenge

Connecting a major solar farm to Christchurch’s grid while working around strict airport night‑time access constraints.

Solution

Ventia designed and built two HV substations and 17 km of cable, coordinating tightly with airport and local partners.

Impact

The project enables reliable clean‑energy flow to Christchurch, supporting regional decarbonisation and future growth.


Ventia is delivering grid connections for one of New Zealand’s largest solar farms - Kōwhai Park, located near Christchurch.  

This project is a cornerstone of the region’s renewable energy strategy, supporting Christchurch’s transition to clean power and enabling future decarbonisation initiatives, including at Christchurch International Airport.

The Ventia team has been undertaking work on the Kōwhai Park Solar Farm since October 2023, initially on planning, design, procurement, and stakeholder engagement before commencing field work in August 2025.  

Our scope across the project includes the design, procurement and builds of two high-voltage substations and 17 km of 66kV cable installation, creating a resilient energy link between the solar farm, the airport, and Orion’s electricity network. 

Transformer with reinforcement installation completed

Helping to connect clean energy to where it is needed

Large-scale renewable generation requires robust infrastructure to connect to the grid. At Kōwhai Park, this means converting power from the solar farm’s 33,000 volts up to 66,000 volts at Pound Road substation, transmitting it via a 66,000-volt cable run that includes 4.5 km of trenching and installation (17 km of cable in total), and then stepping it back down to 33,000 volts at Grays Road substation for future connection to Christchurch International Airport and Orion’s electricity network. The solution needs to handle high-voltage conversion, integrate with existing networks, and meet strict timelines without disrupting critical operations like airport runways.

“It’s one of the largest solar farms in New Zealand,” said Kalim Guthrie who is managing the project for Ventia.

The many kilometres of high-voltage cable we are installing is a major engineering feat on its own, and the future connection to the airport adds a layer of strategic importance.

Meeting the challenge of working near an international airport

One of the major challenges facing the team on this project is the requirement for underground cable installation to be done late at night when aircraft aren’t operating. It requires great planning and execution to dig the trench, put in ducting and then completely backfill the portion they have worked on before service at the airport resumes in the morning.

“It’s super time critical to stick to timeframes because the disruption to the airport would be huge otherwise,” Kailm said.

*Pound Rd (33kV → 66kV) and Grays Rd (66kV → 33kV).

Project progress

After breaking ground at the first substation site earlier this year, the team is rapidly working towards mid-2026 when all assets will be fully constructed, tested, and commissioned. To achieve this, Ventia has built strong relationships with subcontractors, local and international suppliers through early engagement and collaborative planning, partnered with experienced local contractors to streamline approvals, and established a multidisciplinary team with expertise in health & safety, environmental management, quality assurance, and project delivery.

“Managing both substations under a single framework optimises resources, standardises processes, and reduces duplication, Kalim said. 

Our collaboration with local contractors and suppliers is also creating opportunities for regional economic growth, ensuring the benefits of this project flow to the wider Canterbury community.