Battery electric trains are coming (again) to New Zealand

In early September, Marc Daalder of Newsroom published an article with the title ‘Global warming will pass 1.5C. What are you going to do about it?

This prompted an on-line discussion amongst Newsroom subscribers, including some debate about sustainable and unsustainable forms of travel. I added some comments about electric trains already being a climate solution.

This provoked the managing editor of Newsroom to ask the following question.

“Has anyone yet run long-distance battery electric trains to a commercial schedule, Paul? I’m not aware the tech’s there yet. It’s true a Great Western Railway prototype set a record of 322km last year, but it had to maintain a highly controlled speed of 50–65 km/h with the heating and cooling turned off. And then it couldn’t turn around and go home to London – it had to stop overnight to charge.”

The incoming Tūhono fleet will travel 59km under battery power between Upper Hutt and Masterton, and 81km under battery power between Waikanae and Palmerston North. Closer to Wellington on both lines, the new fleet will use existing overhead catenary fed electric power. The Future is Rail acknowledges that, currently, the upper limit for regular commercial operation for trains in battery mode is around 80 to 100km. But the upper range limit continues to increase and, the key point, is that these trains are in regular commercial operation right now.

If we are to quickly and significantly reduce our domestic travel emissions, for longer distance travel the three main options are electric cars, electric trains and electric planes. Some of us already own electric cars and use electric trains to travel in Wellington and Auckland. Tūhono will extend low emission travel options, for thousands more kiwis each day, from when they enter service in 2030.

But the local and international media has been focussing much of their attention to the future of electric flight, including the August 2026 short flight by the Heart Aerospace plane.

This flight was highlighted in a September newsletter by Rewiring Aotearoa, which started with a photo of the Heart electric plane.

Commercial electric planes for regional flights will eventually come. But this enthusiasm for electric planes ignores the long history of electric trains in New Zealand, the great advances being made internationally in battery powered trains and how trains can increase mobility options while at the same time reducing emissions in a very energy efficient manner.

Electric commuter trains have been running on the Wellington rail network since the late 1930s. Electric locomotives currently pull freight trains through the central North Island.

In the past electric trains usually required overhead lines or, in some metros, an electrified rail. But now with advances in batteries, hybrid electric trains are becoming an option for electrifying rail whether passenger rail or freight. The idea of the hybrid system is they can draw power off overhead lines when it is available then switch to batteries.

Battery electric trains already running around the world or coming soon

According to the IEA, globally around three quarters of passenger rail is already electric, but the remaining quarter runs on diesel. It is these diesel trains we need to replace and battery trains now represent a way to do this.

According to the website TrainsPro, battery trains are not new. They report that battery-powered locomotives were built in several countries, including West Germany and Britain, in the 1920s and 1950s. These used lead-acid batteries. This old technology created a number of problems, including the time to charge batteries.

In fact, an early lead-acid battery train operated in Canterbury, New Zealand, for eight years in the 1920s. Built in New Zealand, it travelled on the Little River branch line out of Christchurch. According to Wikipedia, New Zealand Railways claimed it could cover the 36 miles (58 km), 12 stops, journey between Christchurch and Little at an "average speed" of 30 miles per hour (48 km/h).

NZR RM 6, Edison battery-electric railcar in 1926. AP Godber Collection, Alexander Turnbull Library.

The Japanese were early adopters of modern battery passenger trains. According to Hitachi, the BEC Series 819, JR Kyushu’s Dual Energy Charge train started running in October 2016 and was the world’s first AC electrified, overhead power storage electric train. Between 2016 and 2019 an entire fleet of 18 diesel trains was replaced with battery units.

In 2021, the magazine Rail Professional reported these trains had been running for five years, noting that the fleet had reduced CO2 emissions by 2,700,000 kg since its introduction in 2016. With a top speed of 120km per hour, it had by then completed over 5 million kilometres in passenger service in the northern Kyushu region. As added benefits, it was reported that the trains far quieter than the diesel trains they replaced and release no NOx emissions.

Other countries have been catching up.

Reported in the Rail Technology magazine, battery passenger trains have been running in Germany since 2023. They note, when drawing up plans to replace diesel trains in 2015, the government had planned to buy hydrogen-powered trains. However, the battery option was much more economical. German battery electric passenger trains now run on various routes, including the northern state of Schleswig-Holstein and the Ortenau region.

In two regions of France battery electric trains commenced running commercial services in July and September 2026. One is in the Occitanie region on the Nîmes to Vauvert line. The other in the Sud Region operating on the Avignon to Carpentras route.

The website Railway Technology stated that in May 2025 Croatia launched their first battery electric trains as part of a national initiative to enhance ‘green’ technology in public transport. The train runs on the Zagreb – Bjelovar – Zagreb route. They report the train has an operational range of up to 480km per day and can run for up to 18 hours daily.

In early 2026, Great Western Railways launched the UK’s first battery train scheduled service. In early trials in 2023, it set a new world record for the longest journey completed by a battery‑electric train on a single charge — 200.5 miles.

There are many more such trains proposed. For example, in the United States the O’Hare Flyer, a battery-electric express train from downtown Chicago to O’Hare’s airport’s Terminal 2.

Our own modern battery train is coming soon

The Tūhono fleet, made up of 18 five-car battery-electric multiple unit (BEMU) trains, supported by recharge points, maintenance infrastructure, and track upgrades, will be the first of their kind in the Southern Hemisphere.

Their arrival from 2029, is the outcome of a rigorous and exhaustive process beginning in 2017, to successfully establish, develop and receive approval for the case to build a new fleet, using NZ Treasury’s Better Business Cases (BBC) framework.

Initial work on a Palmerston North–Wellington Rail Passenger Business Case, to support continued short-term funding for the Capital Connection, was completed in October 2017 for the Horizons Regional Council and the Greater Wellington Regional Council (GWRC).

The primary purpose of the 2017 business case was to evaluate whether to continue public funding for the Capital Connection passenger rail service beyond June 2018, when its existing funding arrangement was due to expire. A range of options was considered, with a recommendation to continue funding the Capital Connection, develop what became the “new” interim Capital Connection, and develop longer term options.

The indicative business case (IBC); Lower North Island Longer-Distance Rolling Stock Business Case was authored by infrastructure consultancy; Stantec in 2019. It explored a range of options from a “do minimum”, retaining overhauled existing rolling stock on the Wairarapa line and elimination of the Capital Connection between Wellington and Palmerston North, all the way through to full electrification of both lines. The Stantec report made a recommendation supporting DMMUs (dual mode multiple units), but without specifying which combination, which at that stage also included hydrogen, or batteries, but appeared to favour diesel alongside overhead catenary electric operation.

This foundational work directly set up the $5 million funding allocation from Waka Kotahi / NZTA in April 2020 for the Lower North Island Rail Integrated Mobility (LNIRIM) Detailed Business Case (DBC). This document was published in 2021 and was authored by a different infrastructure consultancy; RPS Group, with advisory support from international rail rolling stock specialists, IPEX. The LNIRIM DBC ran through the options in greater detail, alongside other aspects of the strategic case for investment. At that point the favoured option was for a “tri-mode” train featuring overhead catenary electric power, battery power and diesel power.

The business case was approved by government in November 2023. The Expression of Interest (EOI) for the design, build, and supply of the new battery-electric train fleet opened on December 13, 2023, and closed on January 26, 2024. Shortlisted bidders included CAF, Stadler and Alstom. All 3 manufacturers have multi-modal options. Stadler likely offered a product a little like this, while noting that the detail including tri-mode capability will have been equivalent to these trains operating in the UK. CAF are in the midst of rolling out the bi-modal overhead catenary and diesel-powered fleet for New South Wales’s regional network, which are an example of the ‘Civity’ rollingstock platform, available in a range of modal options.

Following a global procurement process, the NZ$1.066 billion major contract was awarded to Alstom on September 8, 2025 with train-sets specified as dual overhead catenary and battery powered.

It should be noted that the Tūhono fleet uses Alstom’s proven Adessia platform and follows 11 BEMU (Battery-electric multiple unit) trains for VMS in Germany and 31 for Irish Rail in Ireland.

A key point is that the Tūhono fleet is being built off a proven rolling stock platform. Furthermore, there are competing rail manufacturers offering equivalent products, which in itself drives improvements.

The Tūhono fleet using Alstom’s proven Adessia platform, is closely based on a fleet of 31 BEMU trains currently being introduced into Ireland.

Also important was the criticality of the NZ Treasury business case process. There were alternatives investigated, including a reduction in the current service offering, and withdrawal of some services. The case for Tūhono, successfully overcame economic and technical hurdles. The outcome is a fleet that will cost 20% of the energy costs of the current diesel locomotive hauled fleet. The length of time (2017-2023) it took to get a business case through the NZ Treasury’s BBC framework is noteworthy. In its own right, it provides a contrast to the way road projects, particularly RoNS are fast tracked.

In this context, the current status for regional battery-electric aviation is at a magnitude of lesser maturity.

Electric planes are coming

Amongst a group of techno-optimists there has been a view that we are heading towards a new age of aviation hypermobility, with small electric taxis serving all small towns and cities, feeding into a larger network of electric planes, then linking to larger airports and long-haul flights. Some of the gloss has now worn off in terms of flying taxis and the development of electric planes that serve regional routes is taking longer than originally forecast. Back in 2021, Sounds Air said it expected to be flying passengers across Cook Strait in a Heart Aerospace electric plane by 2026. Small electric planes have now flown across the Cook Strait, but progress has been slow for Heart Aerospace.

However, mid 2026 did mark the first flight of its ES30 battery electric aircraft in the United States. After 8 years of design effort from initial ES19 concept to the ES30, the initial flight was 27-minutes, the aircraft reached 305 metres altitude, with the all-electric system delivering more than 1 MW of power. It is the largest electric airplane ever flown with a 30.5 metre wingspan, a take-off weight of 11,340 kg, and, apparently, $5 of electricity to get it off the ground. The production model is expected to have a range of 200km in all electric mode, or 800km in hybrid mode. 40% lower operating costs is claimed, along with an entry into service of 2031.

Source: Heart Aerospace website

There are a number of questions and issues. We can speculate about some.

· Take-off weight will be the same as landing weight. Will this impact on airport runway lengths?

· What will be the commercial flying altitude? Getting to altitude is one of the biggest areas of energy consumption for aircraft, yet it is altitude that protects aircraft and passengers from most adverse weather.

· The ES30 is proposed to be single crewed, how does that work in the current regulatory environment, where even for small twin engine commercial airliners, there are two pilots.

· A smaller capacity fleet will require greater frequencies, will use more landing gateways at airports, and will require enhanced flight navigation and tracking systems from Civil Aviation Authority of New Zealand (CAA)

· Scalability is critical in many industries towards gaining efficiencies over time. This is particularly true in the aviation industry where initial models have been stretched over the life-cycle of production. Can ES30 scale in capacity and range, without having to go to hybrid power which Heart Aerospace has also offered. Hybrid power increases operating costs and maintenance complexity, and costs. This may potentially offset any productivity gains due to capacity increases.

· The capital costs are another matter entirely. It is expected that being all-new technology, that pathway towards break-even, will need very careful management, with additional costs also due to having power to recharge facilities at airports. This will impact purchase price, relative to conventional aircraft.

· Given the above, when will Air New Zealand, or other local airlines, be realistically in a position to buy such aircraft?

· Heart quotes 40% lower aircraft operating costs (graph below). However, this means a 30 seat ES30, compared to a typical regional turboprop aircraft such as the 48-seater Q300, that Air New Zealand operators, will have a similar per-seat operating cost.

· What impact on ticket prices for regional passenger services, will aircraft such as the ES30 have? The data provided by Heart Aerospace in the graph, indicates that 30-seater electric planes will not reduce the high-ticket prices for regional air travel, because the per-seat operating cost.

Source: Heart Aerospace website

Further notes on the graph:

a) ‘Cutting regional aircraft operating costs’ assumes that one pilot can operate the plane, with a plan to eventually move to autonomous flight over time. Driverless trains already operate on some metro lines and regional trains could also one day be driverless.

b) The ES30 aircraft is assumed to have lower maintenance costs due to the use of electric motors. Perhaps that is true even with 4 electric prop units powering an ES30, compared to 2 turboprops in a typical current regional airliner. But if the only way to achieve substantially greater range and capacity is through the use of hybrid power, there will be two rather than just one propulsion systems to maintain.

Electric trains and electric planes: Both are needed

To conclude, there will be an important place for both battery electric trains and battery electric planes in Aotearoa New Zealand, where they will serve complimentary roles. Neither option is a complete solution. For example, Palmerston North Airport and transport hub promises to be a great location for battery electric trains and battery electric planes to work together.

Short hop regional electric planes will fill the gap where trains cannot go. For example, Nelson to Wellington. But for trips such as Tauranga to Auckland, Wellington to Palmerston North or Christchurch to Ashburton, an electric train has many advantages.

Footnote: The Future is Rail has been following the advances in electric planes and electric trains for some time. Previous articles include:

https://thefutureisrail.org/trains-versus-planes

https://thefutureisrail.org/flying-taxis-and-electric-planes-are-coming-or-are-they

https://thefutureisrail.org/electric-trains

https://thefutureisrail.org/solving-our-regional-mobility-crisis

The Future Is Rail.

organiser@thefutureisrail.org

022 154 9119