What Ottawa Can Learn From Hydrogen Transit Failures Across Canada and Beyond

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Ottawa’s transit system is working through difficult choices at a moment when reliability, cost control, and public confidence matter more than ever. The fleet is aging, budgets are tight, and ridership is still recovering from the pandemic. Decisions made in the next two or three years will shape the quality of service for more than a decade. When Council debates propulsion technologies, it is not debating an abstract question. It is debating service frequency, fleet availability, maintenance workload, long term cost exposure, and the basic ability of transit to support a growing city.

OC Transpo has roughly 30 battery electric buses in service today, with the rest of its several hundred vehicles still running on diesel or diesel hybrid propulsion. A large share of those diesel buses are aging out of their service life, which makes replacement unavoidable over the next few years. The city is placing a strong focus on high capacity buses because they are essential for restoring reliable and frequent service as Ottawa moves toward a larger electric fleet. And at this point, there is limited experience with high capacity electric buses in Canada, making OC Transpo’s decisions challenging.

My recent delegation to the Transit Commission came about because some councillors had signaled that hydrogen buses might still be under consideration for Ottawa. Councillor Lo’s early draft amendment included language that would have reopened the door to hydrogen. During the meeting itself, comments suggested that some were still interested in assessing hydrogen for transit use. Councillor Tierney, in particular, asked earlier delegations about hydrogen and said the city was considering it for other municipal vehicles. Although the amendment was eventually tightened to only permit diesel and hybrid buses in the near term, those signals made it clear that hydrogen had not fully left the conversation. That is the only reason I proceeded with my delegation instead of simply giving time back to council, the OC Transpo staff and other delegations who were at the end of a long day.

I did not approach Ottawa on my own. I was invited to speak specifically about hydrogen by Raymond Leury, president of the Electric Vehicle Council of Ottawa, after hydrogen buses resurfaced in council discussions. Raymond and his colleagues had worked for years to move OC Transpo toward battery electric buses and were worried that the new motion from Councillor Lo, combined with talk of hydrogen for heavy duty municipal vehicles, was reopening the door to a technology they had already assessed as uneconomic and high risk. They asked me to provide a five minute delegation to the Transit Committee focused on the financial, operational, and climate problems of hydrogen fleets, in part because they wanted councillors to hear that message from someone who spends most of his time comparing real world transit technologies.

My goal was to give councillors access to high quality information about hydrogen in real world transit applications. I presented only factual material from primary sources, including US Department of Energy fleet reports, European JIVE and Clean Hydrogen status documents, Canadian municipal case studies, and peer reviewed research in Nature on hydrogen leakage and indirect warming effects. These are all high reliability sources that document how hydrogen performs outside of marketing material. They show consistent patterns across regions and climates. Hydrogen fuel is expensive because every part of the supply chain increases cost. Hydrogen buses have high maintenance requirements and low availability. Refueling stations are fragile and often down for repairs. Fuel cell stacks degrade quickly under heavy use. Hydrogen leakage creates indirect warming impacts. Fossil hydrogen carries very high upstream emissions. Electrolysis multiplies whatever carbon intensity is in the grid by roughly a factor of three because so much electricity is lost in the conversion and compression steps. Trucking hydrogen long distances adds emissions and operational risk. When I assessed multiple hydrogen bus pilots in Canada and abroad, several would have produced higher well to wheel emissions than diesel if they had continued.

This material was contrasted with the reliability and maturity of battery electric buses. The comparison was based on field data rather than assumptions. Where battery electric fleets struggle, the issues are usually predictable: cold weather range loss, depot capacity upgrades, and charging throughput. These challenges are manageable and declining in severity as energy density improves and as agencies gain operational experience. The direction of cost and capability for battery electric buses is strongly positive. The direction of cost and complexity for hydrogen buses is not.

Ottawa and OC Transpo are managing real constraints. Maintenance staffing is thin. Bus availability is lower than the city needs. Garage facilities require investment. Operating budgets are tight. The city needs propulsion technologies that reduce complexity rather than increase it. Hydrogen buses introduce an entirely new technology class into the maintenance shop, with high pressure systems, complex cooling loops, and balance of plant equipment that demands specialized training and tools. Electric buses, by contrast, share many components with existing diesel hybrids and integrate more smoothly into depot operations. The issue is not ideology. It is the relationship between technology choice and service quality.

During his responding remarks, Councillor Tierney referenced Reddit threads as part of his own information base and noted that I had been named in those discussions as someone against hydrogen, an ad hominem response to a professional providing a delegation and unrelated to the content of my presentation. Reddit is a large online forum where many people discuss hydrogen, transit, energy systems, and a wide range of other topics. I have written a lot about hydrogen, as I have about multiple decarbonization challenges and competitive solutions, so it is not surprising that my work gets mentioned there. For the record, as always, I’m not against hydrogen, I’m against it being used where there are more cost and climate effective alternatives, as is the case with all of ground transportation. The contrast is worth acknowledging without judgment. My delegation referenced work from the US Department of Energy, European hydrogen programs, Nature, and Canadian municipal records. Reddit reflects interest and debate but does not replace direct evidence from the field. None of this needs to be adversarial. It only highlights the importance of grounding major procurement decisions in primary data.

Councillor Tierney plays an important role on Ottawa’s Transportation Committee and the Transit Commission, and he is clearly engaged in questions about how the city should renew its fleet. His interest in hydrogen, and his comments referring to online discussions, show that he is trying to understand a complex topic during a period of rapid technological change. That deserves respect. At the same time, the empirical record on hydrogen in municipal fleets is not on his side. Every major North American and European hydrogen bus project that has produced usable data has encountered high costs, low availability, fragile refueling infrastructure, and early fuel cell degradation. Several Canadian pilots have already been shut down. Even Beijing, a city with a climate very similar to Ottawa’s and which introduced hydrogen refueling stations and buses for the Winter Olympics in 2022 sees shuttered stations and many of the hydrogen buses permanently parked today, per reporting from China. The transit agencies that have abandoned hydrogen have done so because the technology made their service less reliable, not because of ideology.

There is no shortage of peers he could speak with. Winnipeg, Edmonton, Whistler, Cologne, Aberdeen, and several California agencies have all worked directly with hydrogen fleets and can describe their operational and financial challenges in detail. Their experience is more relevant to Ottawa than promotional material or online commentary. If Councillor Tierney seeks out those municipalities and listens to what their engineers and operations teams have learned, he will find that they point in the same direction. Hydrogen is difficult to manage, expensive to operate, and hard on a maintenance workforce. Battery electric fleets, although not perfect, are improving quickly on cost, range, and reliability. Ottawa would be well served by grounding future propulsion decisions in the lived experience of cities that have already traveled this path.

Councillor Tierney is not someone who spends his time in the kind of technoeconomic assessments that transportation and climate technologies require, and his educational and professional background does not focus on that domain. Like most municipal leaders, he depends on expert guidance when decisions involve complex engineering and economic tradeoffs. On hydrogen in particular, he would be well served by seeking out experts who do spend their careers in those technoeconomic assessments, as well as practitioners and agencies that have operated these fleets and can provide grounded advice.

The amendment that passed gives OC Transpo short term flexibility to purchase diesel and hybrid buses to address the immediate fleet shortage. That is a practical decision given the need to keep buses on the road. At the same time, the electric transition is accelerating faster than many realize. Canada already has long range, 60 foot battery electric buses operating in real winter conditions in Winnipeg, a city which attempted to square the fiscal circle of hydrogen for transit and wisely walked away. Their operational data will arrive within months, not years. Battery energy density continues to improve. Charging hardware is becoming simpler and cheaper. Canada’s new transit fund will encourage electrification because the economics increasingly favor it. My expectation is that most of Ottawa’s future long bus purchases over this term of Council will be battery electric because that is where the global evidence points and where federal incentives align.

Although I did not raise it during my delegation because my limited time was focused on entering cost, reliability, and climate evidence about hydrogen fleets into the record, it is worth noting that in-motion charging is growing rapidly in global transit planning. Several European and Asian cities are now adopting electric trolleybus systems with onboard batteries that charge while the bus is moving under short sections of overhead wire. This approach avoids the cost and operational fragility of hydrogen while reducing the need for massive depot charging buildouts and the size and hence expense of on-bus batteries. It also provides significant flexibility because buses can leave the wired sections and operate freely on battery power for the remainder of the route. If OC Transpo is not already examining in-motion charging as part of its long term electrification strategy, it should consider doing so because it aligns well with Ottawa’s operating patterns and offers an additional tool for increasing reliability and managing winter range needs without introducing an entirely new propulsion system.

Ottawa has already made important progress on electrification. The commitment to early pilot projects and to modernizing garage infrastructure set the city on the right path. The debate over propulsion technologies is healthy as long as the evidence is taken seriously. I appreciate that Council has kept its focus on restoring reliability, increasing frequency, and making transit a dependable choice for more residents. Those priorities matter more than any specific technology. As one councilor rightly pointed out, it’s better to get 35 cars off of the road by putting one diesel bus on the road than to leave the cars in operation. And, of course, new diesel buses will last 15 years, committing the city to more emissions and pollution, and so are decidedly imperfect.  I will gladly continue to provide evidence, analysis, or direct support to councillors and staff who want to understand what global transit agencies have learned about decarbonizing fleets while improving service.