NZAS from the air

New Zealand’s Aluminium Smelter


New Zealand’s Aluminium Smelter (NZAS) converts alumina into aluminium using renewable hydroelectricity, resulting in one of the lowest carbon footprints for an aluminium smelter in the world.

The smelter is located on Tiwai Peninsula in Southland and the majority of the plant's alumina is supplied from our Yarwun operation and Queensland Alumina Limited refineries. Around 90% of the aluminium produced at NZAS is exported.

NZAS is a joint venture owned by Rio Tinto (79.36%) and Japan’s Sumitomo Chemical Company (20.64%). 

In July 2020, we announced the conclusion of a strategic review of the smelter and a decision to wind down operations by August 2021 due to high energy and transmission costs. Following negotiations resulting in a new electricity agreement, in January 2021 we committed to continue operating the smelter for an additional four years until December 2024.

The extension provides certainty to employees, the local community and customers while providing more time for all stakeholders to plan for the future.

Innovation at NZAS

Innovation is at the heart of our operation. Our General Manager’s Innovation Awards, held three times per year, recognise creative and practical ways to improve our workplace by reducing risk and adding value.

For example, we have used virtual reality (VR) for more than a decade to create safer, more productive and effective processes. It has been applied to improve training, enrich the understanding of communities about the site, and improve the planning of projects.

Recently we developed an application using VR technology to re-enact an incident. This pioneering use of VR helped to answer questions about the incident, increase learning and improve safety.

We also have a “Leading for Safety” project that pioneered our Vehicle Prestart Check App. This app is being used in production on 40 vehicles – replacing the former paper-based approach. The app allows drivers to use in-vehicle tablets to perform quick and easy checks; it notifies drivers immediately with on-board warnings and guidance if there are any failed checks. The app also provides consolidated reports on the status of each fleet's pre-start checks at a glance.

Latest NZAS releases











2021 figures.
* Employees and Category 1 contractors

Low carbon aluminium

NZAS is proud to have its metal marketed under Rio Tinto's RenewAl brand. As the world moves towards a lower carbon future, the RenewAl brand can help NZAS take advantage of growing demand for high-quality aluminium to be used in more sustainable, low-carbon products. RenewAl certifies NZAS metal as being some of the lowest carbon in the world.

In 2019, the Aluminium Stewardship Initiative (ASI) granted its Performance Standard and Chain of Custody certifications to our NZAS aluminium smelter. ASI certification means customers can be assured that the aluminium they purchase has been produced to the highest environmental, social and governance standards, ranging from greenhouse gas emissions to human rights.

Working at NZAS

NZAS communities

We strive to establish and maintain community relationships that positively contribute to the quality of life where we live and work, and by supporting partnerships that are mutually beneficial and deliver long-term, sustainable results.

We have been the major sponsor of the annual NZAS Southland Science & Technology Fair since 2003. Students are required to investigate a topic of their choice using a scientific method of hypothesis, method, test and conclusions.

We also have a longstanding partnership with Southland Girls' High School, designed to encourage students to pursue careers in engineering and science. Each year we host students at the smelter for a week so they can learn about career options and work on a project gathering, testing and analysing data. 

Through our Partnership to Progress programme, we have committed to provide US$25 million in support to communities during the current COVID-19 pandemic and recovery.

To help support our Southland community, we have donated NZ$100,000 to the Invercargill Women’s Refuge after a significant rise in calls to police and support services regarding domestic violence during and after periods of lockdown. We have also donated NZ$90,000 to Koha Kai’s “Lunches in Schools Programme”, which provides meaningful employment opportunities for people with disabilities while at the same time providing nutritious, affordable food for children in need.

  • Increasing diversity
  • Sourcing locally
  • Cultural heritage

Increasing diversity

We are making an effort to increase our gender diversity through a programme that includes increasing the intake of female apprentices, hosting workshops to focus on how we can attract more women and how our recruitment advertising is pitched. We have a big opportunity to make our site a more diverse and inclusive workplace and we are doing everything we can to step up to that challenge.

Sourcing Locally

We strive wherever possible to buy locally and employ locally, investing in our community by supporting economic activity and contributing towards a sustainable future.

We also focus on training, apprenticeships and employment opportunities. Our graduate programme is designed to attract and develop employees to bring fresh thinking, different perspectives and new skill sets.

Cultural Heritage

We have identified 27 cultural heritage sites located on land owned and managed by the smelter. They include European burials and structures, as well as Māori sites such as middens/ovens, burials and an adze workshop. Wahi tapu, wahi taoka and mahinga kai are also present on Tiwai Peninsula. We have a Cultural Heritage Management System Plan in place to look after these important sites.

NZAS contacts


Tiwai Road
New Zealand

T: +64 3 218 5999

Postal address

Private Bag 90110
New Zealand

Community enquiries

E: NZAS Community Enquiries
T: +64 3218 5440