Bigger than Tiwai Point and nobody’s talking about the wires
Datagrid New Zealand has secured full resource consent for a 78,000 sqm, 280MW data centre campus at Makarewa, north of Invercargill. The $3.5 billion facility will be New Zealand’s first hyperscale AI data centre, and its first phase alone would make it the country’s second-largest electricity consumer after the Tiwai Point aluminium smelter. At full build-out, it will require double Tiwai Point’s load, making it the single biggest draw on the national grid.
The coverage so far has been celebratory. Jobs, innovation, Southland’s moment in the sun. What’s missing is the harder question: who pays to make the grid capable of delivering that much power to a single regional node?
The grid wasn’t built for this
Datagrid CEO Perrine Dhalluin has been refreshingly direct about the constraint. “Power is the main barrier and it needs to be green, stable and at an affordable price,” she told the Southland Chamber of Commerce. The company says it is confident of accessing 240MW from the existing grid for its first phase, targeting a 2028 opening. The facility will include a dedicated Grid Exit Point substation.
But a connection substation at the facility boundary is not the same as the upstream transmission reinforcement a 280MW concentrated load demands. Transpower has made no public statement on what grid upgrades will be required, what they’ll cost, or who will pay. That silence is the story.
To put the scale in context, New Zealand added 556MW of renewable generation capacity across the entire country in 2024. Datagrid’s first phase alone would consume roughly half that in a single facility. And industrial electricity consumption was already up 10.8% year-on-year in the September 2025 quarter, before Datagrid draws a single megawatt.
The cost-shifting problem nobody wants to name
Under New Zealand’s transmission pricing framework, grid upgrade costs are partially socialised across all connected users through Transpower’s revenue cap and the Electricity Authority’s pricing methodologies. The Electricity Authority’s own Q1 2025 market performance review already flags significant price volatility driven by hydro storage levels and thermal outages. Adding a 280MW concentrated load amplifies that volatility.
Genesis Energy CEO Malcolm Johns has been explicit about the risk: “There is a risk that data centres will create more volatility in the electricity system.” He categorises AI-intensive data centres as the most demanding load type, not comparable to conventional data warehouses.
Southland and the broader South Island host dairy processing, meat works, aluminium smelting, and other manufacturing. These businesses have built their cost structures around existing transmission pricing. If Transpower must upgrade South Island infrastructure to accommodate Datagrid and those costs are socialised, every one of those businesses faces higher transmission charges. They’d effectively be subsidising a new entrant’s power supply.
The Tiwai smelter has long operated demand response arrangements with Transpower, acting as a grid management tool as much as a commercial operation. AI inference workloads don’t offer the same flexibility. They’re latency-sensitive and continuous. You can’t tell an AI model to pause mid-computation because the grid is under stress.
Ireland tried this and it didn’t go well
The international precedent should give pause. Ireland’s South Dublin County Council passed a motion calling for a moratorium on new data centres after the region accumulated at least 30 facilities that overwhelmed the local grid. In the US, Big Tech companies are reopening nuclear plants to secure dedicated generation, a sign of how far grid stress is pushing the industry toward self-supply.
New Zealand’s 89.4% renewable generation share is a genuine competitive advantage for attracting data centre investment. But a high renewable share in generation doesn’t mean the transmission network can deliver that power wherever a hyperscaler wants it.
The question that needs answering before 2028
Datagrid’s project has real potential. The Tasman Ring subsea fibre cable, landing at Oreti Beach with 540 terabytes per second capacity, would be the South Island’s first international subsea connection. The construction phase promises 1,200 jobs. New Zealand genuinely needs to be in the AI infrastructure game.
But wanting something doesn’t mean the costs should be hidden. Transpower needs to publish what grid upgrades this project requires and what they’ll cost. The Electricity Authority needs to clarify how those costs will be allocated. And if the answer is socialisation across all users, then the government needs to explain why a dairy processor in Timaru should pay more for electricity so a hyperscale data centre can sell AI compute to offshore clients.
The project is exciting. The silence on who pays for the grid is not.
Sources
- BusinessDesk: Hyperscaler Datagrid gets approvals for 280MW Southland data centre
- NBR: Datagrid receives resource consent for ‘AI factory’
- ITBrief: Southland’s first ‘AI factory’ data centre gets go-ahead
- PropertyNZ: Datagrid targets 2028 opening for Southland hyperscale data centre
- Southland Chamber: Datagrid eyeing 2028 opening of new data centre
- MBIE: September 2025 summary – New Zealand Energy Quarterly
- MBIE: Energy in New Zealand 2025
- Electricity Authority: Market performance review Q1 2025
- NZ Herald: Genesis Energy CEO bets on AI growth but warns of data centre challenge to power grid