“Everything you do has an impact on carbon. Away from our landfill emissions, about 80 per cent of our carbon comes from diesel. We look at moving to LED lighting and managing our internal waste consumption, but diesel is where we can make the biggest difference.”
In 2016, Waste Management decided to shift from diesel power to using electric trucks. At that time there were few options. “We did a global search and found no one was selling electric trucks off the shelf,” says Maehl. “So, we went to a company in the Netherlands called Emoss that did diesel-to-electric conversion kits. Many companies said they did this, but Emoss had trucks operating on the road in Europe.”
At first, Waste Management sent its trucks to Europe to be converted. This allowed Emoss to learn about the vehicles and the company’s specific needs. Now Emoss sends conversion kits to New Zealand and Waste Management does its own conversions.
Today it has 32 electric trucks on the roads. Maehl says by the end of the year there will be 52. The company switched to electric vehicles for its sales team which brings the total electric fleet to around 90. He says he is still waiting for a suitable replacement for the company’s utes.
The EV market is still evolving. When it started moving over to electric, Waste Management struggled to buy the Nissan Leaf cars it needed because New Zealand supplies were constrained. The company visited the last Brisbane truck show before the Covid-19 pandemic and found just a single electric vehicle, this year there were 25 different models.
There’s a way to go yet.
Waste Management operates 900 trucks. About 80 per cent of these are perfectly suited to current electric technology. They operate from the company’s base and travel less than 200km in a day which means they can be recharged overnight. Maehl says electric vehicles lose some of their payloads as they carry heavy batteries, but the emissions savings are substantial. For the 20 per cent of the fleet that is harder to switch to EV, Waste Management is considering hydrogen power, but the technology isn’t suitable yet.
While electric trucks cost more upfront, there is less to go wrong, so they last longer than conventional trucks. And there are savings on diesel; Waste Management consumes a million litres of diesel each month.
Waste Management’s first electric truck has been operating for six years. In that time, it has done 150,000 km. “If it was a diesel truck, it would have had its brakes replaced six times. It hasn’t been done once in that time because it uses regenerative braking. People tend to fixate on EV battery life, but the truck has had zero battery degradation. It has battery packs with telemetry on each cell,” Maehl says. “If there is a bad one, we simply pull it out and replace it.”
The company’s focus on electric vehicles is deliberate.
Transportation makes up around 30 per cent of New Zealand’s gross carbon emissions. Landfill sites account for 3.4 per cent of the total. Waste Management is the largest Class One landfill operator and accounts for 0.14 per cent of New Zealand’s emissions.
Circular economy
Waste Management is wedded to the idea of the circular economy. The company’s landfills are a long way from what most New Zealanders think of when they hear the term.
“People have this idea of the local tip where you turn up with a trailer and push off your rubbish then scurry around looking at what’s there,” says Maehl.
“This might be what you see at a council tip, although thankfully most of them have closed. Our landfill sites are nothing like that. We have modern engineered landfills. They are fully lined and capped as we go so that nothing can escape out.
“We process the leachate and more importantly, we capture the biogas. Right from the beginning of the landfill, we have gas wells going down into the landfill. The landfills are under a slight negative pressure, which sucks that biogas out. We then put this through generators and turn that into electricity. Our landfills produce 25 megawatts of power.”
Maehl says Waste Management captures 95 per cent of the methane emitted at their landfills.
That’s using the Ministry of the Environment’s calculation and the process is audited each year by PwC. At the company’s Redvale site near Dairy Flat, gas and heat are pumped to a local aubergine grower. Waste Management also uses the power for its electric vehicles.
Waste Management has been capturing gas and generating electricity from waste for more than 25 years. When the company listed on the NZX, the US Waste Management business was an investor and injected its intellectual property. Maehl says the landfill operation is world-class.
It’s not just about greenhouse gas emissions. “When organic waste arrives at the landfill it is around 80 per cent water. We capture the leachate to ensure it doesn’t stay in the landfill. Instead, we treat it to make it safe,” he says.
“After we close a landfill, we cap it. There is roughly a metre of clay at the bottom, around the sides and at the top. It is like a big, closed pot. There is a 30-year aftercare period.
“We carry on capturing gas and generating electricity. Over time it becomes inert. Then that land becomes available for parks, recreation and other uses.”
· Waste Management is an advertising sponsor of the Herald’s Sustainable Business and Finance report.
