Turbines: 40
Installed capacity: 192MW
Estimated annual generation: 535GWh
Status: Under development
Investment: $506m
We achieved Fast-track approval to develop Puke Kapo Hau Wind Farm, Stage 2 of our Mahinerangi Wind Farm project in April 2026.
The Mercury Board decided to proceed with the expansion in August 2026. Final grid connection studies are being completed with Transpower.
Puke Kapo Hau (Stage 2) will comprise 40 turbines, installed capacity of 192MW and an annual generation of about 535GWh, enough to power the equivalent of about 76,000 average homes every year*.
The full wind farm site covers about 1700ha on the eastern foothills of Lammermoor Range, about 5km north of Lake Mahinerangi and 50km west of Dunedin.
We are investing $506 million in this project and construction is expected to start before the end of 2026, with first generation by mid-2028 and full generation by late 2028.
*based on NZ average household electricity consumption of 7,000 kWh per annum.
Maps
Click here for map of wind-turbine locations.
Click here for map of the planned transmission line for Puke Kapo Hau and the Battery Energy Storage System.
We submitted our plan for Puke Kapo Hau to the Fast-track process and it was approved in July 2026. The plan was approved by our board in August 2026. Final grid connection studies are being completed with Transpower.
Fast-track requires more detailed information upfront for an application to be considered. However, the benefit is a streamlined, all-in-one approval process that helps move quality projects forward more efficiently.
The process took about nine months. An independent panel made the final decision, and you can read more about the process on the Fast-track website.
No. Regardless of process, we remain committed to developing and delivering our projects by engaging with iwi, community and stakeholders (landowners, councils, Department of Conservation), always considering their thoughts and concerns on the impact on the environment.
We’ve been engaging with the neighbours and local community members including Lee Stream School (we love Lee Stream School). We are building a mailing list to keep local people in the loop and to hear concerns and questions, you can join on: mahinerangiwindfarm@mercury.co.nz.
Yes. A key difference with our project is that it has already been through an Environment Court process in 2010 and so the environmental effects of the original wind farm are accepted. Our updated plan includes new wind turbine technology which will reduce the number of wind turbines we’ll need, therefore reducing the project footprint.
We will need about 75 full-time workers on average over three years to construct the wind farm. At the peak of construction, there will be a workforce of about 300 people. These are specialised roles and people with these skills can be found in the Otago and Southland regions.
The new wind farm will help increase renewable energy generation and overall electricity supply for New Zealand. It will deliver 55% of the annual new generation required to meet forecast energy demand and make a significant contribution to meeting the Government’s emission reduction targets.
It will support electrification of the economy and support reduction in greenhouse gas emissions by displacing gas and coal generation.
We have invested $1b over two years in three new energy projects that will deliver 1.1TWh. That includes the Kaiwera Downs Wind Farm Stage 2 in Southland, the Kaiwaikawe Wind Farm in Northland and the expansion to our Ngā Tamariki Geothermal Station near Taupō.
Our plan to develop Mahinerangi, and options to develop the proposed Waikokowai Wind Farm in the Waikato and Puketoi Wind Farm in Tararua, along with possible geothermal and solar opportunities, will help us achieve our plan to deliver 3.5TWh by 2030.
To learn more or arrange to discuss with a member of the team, contact us at mahinerangiwindfarm@mercury.co.nz