Grays Hills

Formerly Mackenzie Basin

Solar Farm with Battery Energy Storage System

Overview

Grays Hills (formerly Mackenzie Basin) is a proposed up to 1200-megawatt (MW) solar energy project with an integrated 300 MW / 1200 MWh battery energy storage system (BESS). Located near Tekapō in the Mackenzie District, the project is designed to harness the region’s exceptional solar resource to deliver clean electricity for homes, industry, and future energy-intensive developments such as e-fuel terminals and data centres.

Set against the high-country landscapes of Te Manahuna, the site carries both opportunity and responsibility. Grays Hills reflects a commitment to environmental stewardship and strong community partnerships, aiming to deliver lasting economic, environmental, and cultural benefits for generations to come.

1200 MW+
Peak Power

300 MW
Battery Energy Storage Capacity

2000 GWh
Annual generation

275,000 homes
Energy supply equivalent

Grays Hills is a proposed up to 1200-megawatt (MW) solar farm with potential for a 300 MW / 1,200 MWh battery energy storage system (BESS) located southeast of Twizel, in the Te Manahuna Mackenzie District.

The project will utilise the region’s strong solar potential to deliver large-scale renewable electricity and support future energy-intensive developments such as e-fuel terminals and data centres.

Strong solar resource: 1,509 kWh/m²/year Global Horizontal Irradiation Ideal terrain: Flat land, minimal earthworks, national road access Land classification: LUC 6 and LUC 7 – non-arable with high solar suitability Energy Impact:

  • Up to 1200 MW+ solar capacity generating up to 2000 GWh/year

  • Enough to power over 275,000 homes across Aotearoa

  • Potential integrated 300 MW / 1,200 MWh BESS to support grid stability and firm supply

Grays Hills is more than a solar project — it’s a commitment to kaitiakitanga, renewable energy, and shared prosperity. Together with mana whenua, local communities, and partners, the project aims to create a lasting positive legacy for Aotearoa’s clean energy future.

Location

Project Lifecycle

  1. Concept

    Potential sites are mapped and studied, with early engagement to understand landowner interests and opportunities.

  2. Feasibility

    Detailed wind, solar, and environmental assessments confirm whether a site can support a commercially and technically viable project.

  3. Project Development

    Current stage

    Planning approvals, community and iwi engagement, and commercial agreements are advanced to prepare projects for financial close.

  4. Construction

    Turbines, solar panels, and infrastructure are built and connected to the grid, creating jobs and local economic activity.

  5. Operations

    Projects deliver clean electricity to the market while being actively monitored, maintained, and optimised for performance.

  6. Decommissioning

    At project end-of-life, assets are dismantled or repowered, and land is responsibly restored for future use.