NZ Bus set to electrify public transport

This story first appeared in the May issue of EVTalk – CLICK HERE to download the magazine FREE

NZ Bus chief executive officer Zane Fulljames explains why the company is moving forward with an electric-powered fleet.

NZ Bus recently announced plans to invest NZ$43m in Wrightspeed electric powertrains to enable NZ Bus to transition to electric-powered vehicles for public transport. With nearly 82% of New Zealand’s electricity from renewable energy sources, transition to electric-powered public transport, alongside private vehicles, will deliver a step change in reducing the country’s carbon footprint.

“While the technology we are deploying does not deliver a fully electric solution immediately, it is as far along the technology curve as it is currently possible to get while remaining commercially viable in the New Zealand context,” says Zane Fulljames.

“At the current point in time fully electric vehicles are costly, given relative economies of scale, and not always reliable, particularly given the topography of some urban areas like Wellington.

“We looked at diesel hybrids, but in our view they are transitional technologies at best (a diesel hybrid will only ever be a diesel hybrid). Investing in the Wrightspeed powertrains enables us to leapfrog that technology to one that is not only already better but is also future-proofed.

“The way the Wrightspeed electric powertrain works is that electric motors, powered by batteries that store electricity, drive the wheels. The powertrain’s regenerative braking capability means that the energy created by braking is able to be converted to electricity, recharging the batteries on the go.

“When the batteries do run low, an on-board range extender (or generator), which is powered by fuel, kicks in. Crucially, this technology is fuel agnostic, which means it can run on any fuel including biofuel, landfill gas and natural gas, so it is not accurate to assume it would run on diesel (as a diesel hybrid inherently does),” says Zane Fulljames.

“We estimate that the range extender (and fuel used for it) will only be used for a small proportion of the time and the rest of the time the vehicles will run entirely on electricity. From our modelling, even in the worst case scenario – on the most topographically challenging routes – the fuel-powered range extender would only be required 17% of the time. On other routes, fuel may be required as little as 8% of the time or in some cases even zero, subject to logistics around vehicles topping up at electric charging stations in depots.

“A key feature of the powertrain is that it enables ‘geofencing,’ or programming the buses to run solely on electricity on specific parts of any particular route, such as key urban areas. Once battery technology improves, the range extender can simply be removed to create a fully electric vehicle.

“With this new technology, our focus in the near term will be on re-powering our trolley buses. This makes sense given they have around 10 years of life left and it means that instead of scrapping them, we can put them back on the road anywhere in New Zealand, without the need for them to be connected to an overhead lines network.

“After we’ve successfully re-powered the trolley buses, we’ll then look at retrofitting of the Wrightspeed powertrains to other selected vehicles types in our fleet, which will deliver substantial reductions in emissions and noise pollution. Passengers will also notice a difference, as buses fitted with the new technology will have much smoother acceleration and are very quiet.”

A comparison between heavy diesel vehicles and vehicles fitted with a Wrightspeed powertrain, even using diesel to fuel its range extender, found that the Wrightspeed powertrain emitted approximately one-tenth of the CO2 emitted by a heavy diesel vehicle. In addition, the NOx and particulate emissions are almost zero.

“Wrightspeed’s range-extended electric vehicle powertrains are already in use successfully in the USA in waste management and delivery vehicles. As you would expect for an investment of the magnitude we have announced, we undertook full due diligence. Wrightspeed’s technology outperformed the competition on nearly every metric, including efficiency, economy, emissions, power and performance, while also enabling compliance with requirements in terms of weight and passenger numbers,” says Zane Fulljames.

“Electric-powered vehicles will inevitably be part of the future. As a major transport operator, we’re excited to be at the forefront of accelerating evolution to electric-powered public transport in New Zealand. This deal with Wrightspeed builds on our track record of innovation and reflects our commitment to continuous improvement to deliver efficient, reliable and accessible bus services.”