Tomato crops are thriving in Reporoa, powered by what Aucklanders are throwing in their green bins.
Auckland’s food scraps collection and a clever process called anaerobic digestion are helping to cut landfill waste, reduce emissions, and reuse organic material as energy and fertiliser.
Unknowingly fuelling this transformation are families in Auckland, such as Ōtara resident Tyra
Their food scraps – and those of thousands of Auckland households – are collected weekly and transported to Ecogas, a processing facility in Reporoa, in the Rotorua Lakes district.
Food scraps are broken down without oxygen to generate renewable energy, liquid fertiliser, and soon, carbon dioxide to enhance glasshouse tomato growth.
Tyra, who declined to give her full name, said using the green bin was now second nature – and surprisingly effective for cutting down on food waste.
“Our food wastage was a lot at first, because you don’t take it into mind when you’re throwing it away, until you have to bag it. So it’s also helped us only cook enough for one or two meals,” she said.
Freezing out the flies and maggots
Her family of three adults, with children coming and going throughout the week, collected scraps in an old ice cream container and stored them in the freezer – a system that’s eliminated smell and pests.
“It stops odour and also the potential of maggots – ’cause I hate those with so much passion,” she said.
“Honestly, freeze it. You won’t get maggots. Don’t put it in your green bin until the night before or early morning of.”
Tyra said the small habit shift had made a big difference to how their household managed rubbish.
“Our rubbish bags don’t stink of rotten food anymore.”
But she acknowledged that for many Pacific households, sustainability often took a back seat to survival.
“It’s definitely comfort and convenience. Plus when was the last time you saw our island families have someone sit down and explain where their food waste goes and also the benefits? I’m thinking of our friends who have nine kids under their roof… and just trying to keep the house afloat – sustainability is very, very low on the list.”
Have more scraps than the bin can hold?
To support larger or busier households, Auckland Council allowed residents to request a second green food scraps bin at no extra charge.
Households could contact Auckland Council or visit their bin request page to request a free bin.
Glen Innes resident Banks shared a different motivation. For her, the appeal of the food scraps bin lay in what it turned into – not what it took away.
“I love that it’s turned into fertiliser and renewable energy,” she said. “I use it religiously. Put it out every week.”
Her household of four adults and a child used the bin consistently.
“Our red bin – for landfill – fits all our rubbish now because it’s not filled with food scraps anymore.”
But Banks believed the slow uptake across Pacific communities had more to do with communication than with attitude.
“Do you know how many years it takes to change our Pacific Island families’ mindsets on a lot of things? This is one of them,” she said.
“Plus, we benefit from visual understanding – in our own language.”
Fale Andrew Lesa, the only Samoan member on the Manurewa Local Board, said his family already had their own way of dealing with food scraps – one that worked just fine for them.
“We use ours for storage,” he said. “Because our food scraps go into our own gardens at home.”
Lesa said many residents would have preferred to opt in rather than have the system automatically rolled out.
Most people either didn’t have enough food scraps to justify the service – or preferred to use it on their own gardens, Lesa said.
“For us, we didn’t want to use it, especially in the summer when it attracts flies. And the stench.”
Where do the scraps actually go?
So what happened to the scraps that were collected?
At the Ecogas facility in Reporoa, anaerobic digestion converted them into heat, energy and fertiliser.
Heat from the process powered a nearby five-hectare glasshouse that produced tomatoes – enough to heat around 2000 homes. Soon, the glasshouse would also get CO2 from the food scraps to help the tomatoes grow even faster.
The remaining energy was fed into the national gas grid, and what was left became “JAFA juice” – liquid fertiliser used by farmers in the region to replace synthetic products.
Auckland Council General Manager of Waste Solutions Justine Haves said it was more than just reducing landfill costs.
“Sending waste to landfill is the most expensive way to dispose of a community’s waste from an environmental perspective,” she said.
“The more waste we have going to landfill, the more harmful emissions we have and the more landfill capacity we need, which comes at a significant cost to communities.”
