Yesterday, the company marked the milestone with a celebration at its Rattray St site, complete with a symbolic flipping of the switch.
However, the new 3MW boiler — which replaced a LPG model — had been running in its test stages for the past six weeks.
Lion sustainability director Justin Merrell said as soon as it was up and running, the brewery’s emissions dropped.
Over the lifetime of the boiler, it was expected to save more than 18,000 tonnes in greenhouse gases.
"Staff are not handling LPG any more," Mr Merrell said.
Lion chief operating officer and New Zealand director Craig Baldie said the company had reduced its total emissions company-wide by an "extraordinary" 60% and the recycled content in their packaging now sat above 70%.
"It's achievements like these that have allowed Lion to become New Zealand's first carbon net-zero brewery."
In total, the boiler cost $7.2 million — $1.5m was invested by Aurora Energy in the electricity upgrade required and $1.6m was co-funded by the Energy Efficiency and Conservation Authority.
Lion capital programme manager Logan Campbell said the project had been in the works since 2022.
The boiler was procured by Windsor Engineering Group, the electrical infrastructure by NES Central and Beca in Dunedin did the initial design work.
"Three years of work then eventually get to this point ... it's been really good, actually.
"It's a huge achievement.
"It sets us up a pathway forward for what we may want to do in the future at other sites — we’ve all learnt loads through the whole process," Mr Campbell said.
