More than meets the eye: Turning transformer trouble into sustainable success

What started as an unexpected failure on a key piece of machinery has ended as one of the most ambitious and successful recycling projects Meridian has ever undertaken. 

A failure in one of two transformers at Meridian’s West Wind site last May left the team with just one working transformer and scratching their heads about what to do with the other one – all 100 tonnes of it. 

“We decided that it wasn't cost effective to repair,” said West Wind Site Owner Hamish Walker. 

“One of the questions we asked was, what's best for business? Do we pick this failed transformer up, plonk it next to it, and just leave it there?”  

Ultimately, that decision was guided by a combination of economics and environmentalism. Senior Project Manager Jade Lloyd said it was quickly obvious that the best and only acceptable option for Meridian was to salvage as much of the failed transformer as possible. 

Of the roughly 100-tonne transformer and 36,000 litres of oil, the team estimates that just three tonnes of wood, oil-soaked wood and paper were unable to be repurposed, recycled or reused. 

Lower Hutt-based supplier Macaulay Metals was engaged to assist with the removal of the transformer. Because its size made it very hard to transport it on the winding rural roads leading to and from West Wind, it was dismantled on site into its component parts.

“They took the tank away, pulled all the copper out, and that's going away and getting recycled. And they pull all the steel laminations, which is the majority of the weight there. Then they get chopped into smaller laminations and get reused in smaller transformers,” said Hamish Walker.

Following five months of meticulous planning, the scrapping process took just two weeks, starting with 36,000 litres of oil being drained for recycling. The oil regeneration alone has saved about 157 tonnes of CO2 emissions over the equivalent volume of imported new oils.

“We sent that off to eNZoil, a transformer oil company in New Zealand that regenerates the oil so that we can buy it back at a cheaper rate and reuse it in our new transformer, which is an awesome sustainable win for us, said Jade Lloyd. 

And the team was also focused on ensuring workers were kept safe in the challenging conditions. 

“I’m very proud of the project managers and the engineers and the team that carried out the work,” said Hamish Walker. 

“We had adverse weather conditions while we were doing it. We did it safely, and we did it with minimal environmental impact. 

“And what we’ve learned throughout this process is so valuable for the next time we’re looking to replace major pieces of machinery or equipment.  

A replacement T2 transformer is expected to arrive at West Wind in early 2025.