The Ports of Auckland has ordered a full-size electric tug boat to replace one of its current diesel fleet as part of a goal to have zero carbon emissions by 2040.
A full-sized tug is capable of 70-tonnes of pulling power but uses 200,000 litres of diesel a year.
A new suggestion to keep its strength but lose the emissions is to use a battery powered version.
"We want to be a leader globally in sustainability and this is the first step." Ports of Auckland Chief Executive Tony Gibson told 1 NEWS.
Climate Change Minister James Shaw believes this will begin a "significant" trend.
An 'e-tug' is said to need a charging station and will last around four hours before needing a boost.
The Ports won't disclose the cost, but it is understood to be up to $18 million.
"Over the life of the vessel we'll save about two and a half million dollars, so yes the capital cost up front is more, but the cost of operating it is a fraction of operating a diesel tug." Auckland Mayor Phil Goff says.
"There will be other ports around New Zealand saying, 'hey this is a great idea'."
"It's the tugs now, it'll be the ferries in the near future but very soon we hope it'll be all of our bus fleet as well."
The new e-tug is expected to replace their oldest vessel in 2021.