What is a Toei Bus fuel cell bus - hydrogen power and EV buses

A fuel cell bus makes its own electricity from hydrogen, and all it emits is water

Wait at a bus stop for a while and you may notice one bus that behaves differently from the others. There is no engine note as it pulls away, and none of the faint jolt that comes when a gearbox changes ratio. That bus is a fuel cell bus. A fuel cell bus carries hydrogen as its fuel, reacts it chemically with oxygen from the air to generate electricity, and uses that electricity to turn a motor. While it is running, the only thing it gives off is water. The Tokyo Metropolitan Bureau of Transportation describes it in exactly those terms, as an environmentally friendly bus that emits nothing but water while in motion.

Toei Bus ran a driving demonstration test in July 2015, brought two vehicles into the fleet in fiscal 2016, and then, on March 21, 2017, began the first service in Japan operated with a commercially sold fuel cell bus. The route chosen for that start was Route To-05, running from the Marunouchi South Exit of Tokyo Station to Tokyo Big Sight, a stretch that ties the city's front door to the waterfront district. The number of vehicles grew from there, and 80 fuel cell buses were in service as of April 1, 2025.

From here, this article follows the path by which hydrogen becomes electricity and the bus begins to move, then turns to what a passenger actually notices on board, how these buses differ from EV buses, and how to tell one apart from an ordinary bus before you board. No specialist knowledge is assumed, so read on with confidence even if chemistry was never your favorite subject.

Following the process in three stages, from the hydrogen tank to the wheels

As the name says, the heart of the vehicle is a device called a fuel cell. The journey from hydrogen to a turning wheel is easiest to grasp if you break it into three stages.

Stage one is carrying the hydrogen. The gas is stored in high pressure tanks mounted on the roof of the body. For the vehicles that joined Toei Bus in 2017, the published figures give a nominal working pressure of 70 MPa (roughly 700 atmospheres) and a combined internal capacity of 600 L, and Toyota Motor Corporation, which developed the vehicle, states that ten high pressure hydrogen tanks are fitted.

Stage two is making electricity from that hydrogen. Hydrogen is fed from the tanks into the fuel cell, where it reacts chemically with oxygen drawn in from the surrounding air, and the reaction produces electricity. Nothing is burned to obtain force, as it would be with diesel fuel. The electricity comes out of the reaction in which hydrogen and oxygen join to form water, so there are no combustion exhaust gases. What is left behind afterwards is water.

Stage three is turning the motor with that electricity. The generated power goes to the motor, and the motor's rotation drives the wheels. The published figures for the 2017 vehicles put the maximum output of the fuel cell at 114 kW × 2 and the maximum output of the motor at 113 kW × 2. Because there is no engine on board, Tokyo Hydrogen Navi lists low noise and low vibration among its characteristics.

For reference, here are the main published figures for the vehicles introduced to Toei Bus in 2017. Vehicles have been renewed as the fleet has grown, so please read the table as a record of what was introduced at the outset.

What you notice on board - the quiet, and the smoothness of pulling away

A difference in mechanism shows up as a difference in the ride. Tokyo Hydrogen Navi, the metropolitan government's information portal on hydrogen, lists the following as characteristics of the fuel cell bus.

• Little noise and vibration - there is no engine on board. Nothing idles while the bus is standing at a stop, and conversation inside the cabin is easier to follow.
• No shift shock - with no gear steps, you never feel the body of the bus surge slightly back and forth partway through acceleration.
• A gentle start - the vehicle has an acceleration control function that holds sharp acceleration in check. For anyone standing and holding a strap, this is the difference that is easiest to feel.
• A camera system that assists visibility - eight high definition cameras inside and outside the vehicle help the driver see.

Because a motor can deliver force from low revolutions, there is none of the brief gathering of effort you sense as a bus sets off. Passengers who are prone to motion sickness, or who like to read on board, may notice that the quality of the movement has changed. That said, the bumps in the road surface and the repeated stopping and starting of heavy traffic are the same whatever the vehicle, so please keep using the handrails and straps inside the cabin during busy periods.

Incidentally, Tokyo Hydrogen Navi introduces the buses the Bureau operated as of April 2024 as SORA, Toyota's fuel cell bus. The name strings together the initials of Sky, Ocean, River and Air, which stand for the circulation of water around the earth, and it says plainly what kind of vehicle this is: one that gives off nothing but water as it runs. The first vehicles delivered in 2017 carried the model name Toyota FC Bus.

The difference from an EV bus is whether you refill hydrogen or recharge electricity

The fuel cell bus is not the only kind of bus that produces no exhaust gas while running. There is also the EV bus, which the Tokyo Metropolitan Bureau of Transportation describes as a bus that drives its motor with electricity charged into an onboard battery from an external power source and gives off no exhaust gas while running. Both types are alike in being driven by a motor. Where they part company is in how the energy is carried. A fuel cell bus is filled with hydrogen and then makes electricity on board, while an EV bus is charged with electricity from an outside supply and carries it in a battery.

Toei Bus received two EV buses at the Kita bus depot in June 2025, and service on a revenue route began on June 10, 2025. It is a pilot introduction, intended to verify matters such as vehicle performance and efficient ways of charging, and it forms part of an initiative under a cooperation agreement concluded with Tokyo Electric Power Company Holdings on September 21, 2023. The exterior carries a special design, a large plug drawn on Edo purple, and the cabin has a full flat floor with no step all the way to the rear. Thin solar panels with a maximum output of 10 kW were also installed on the wall of the depot building at Kita.

How fuel cell buses spread through Toei Bus, and their power to keep the lights on

What began with two vehicles had reached 80 as of April 1, 2025. Tokyo Hydrogen Navi records that, as of April 2024, the Tokyo Metropolitan Bureau of Transportation operated more of these buses than any other bus operator in Japan. That figure is easier to place alongside the size of the Toei Bus fleet and route network as a whole, so for the wider picture see Toei Bus in numbers as well.

More vehicles mean somewhere is needed to replenish the hydrogen. The Bureau built a hydrogen station inside the Ariake bus depot, the first such station on the grounds of a bus depot in Japan, and put it into operation on April 1, 2025. When refueling can be done on depot land, everything a bus needs before it sets out is completed within the depot itself.

The other thing worth knowing is the vehicle's character as a power source on wheels. A fuel cell bus carries a high capacity external power supply system, which allows it to send electricity to an evacuation center or similar site in an emergency. The published figures for the 2017 vehicles gave that supply a maximum output of 9 kW and a supplied energy of 235 kWh. In an emergency, in other words, the bus is intended to serve as a power source for an evacuation center or similar site. Carrying passengers on ordinary days, and carrying electricity when things go wrong. It is this second role that lifts the fuel cell bus out of the plain category of a low emission vehicle.

How to spot one, and what you can do next

So how do you actually get to ride one? There are two things to go on.

1. Recognize the vehicle by its shape - the hydrogen tanks sit on the upper part of the body. Tokyo Hydrogen Navi introduces the look of SORA as futuristic, and it does not look like an ordinary route bus. The EV buses wear a large plug on Edo purple, which makes them obvious at a glance.
2. Look them up in the service information - the Bureau explains that the operating information for fuel cell buses can be checked through the wrapped bus search on the Toei Bus service information site tobus.jp, under the entry for FC buses. For EV buses, the same site's vehicle search under the entry for EV buses is where you are directed.

If you want to ride one on purpose, the surest approach is to check the service information for the vehicles moving that day and then head for a noriba served by the route they work. When you want to know how long the wait will be, the top page of Busdoko shows the positions of the buses in service and the expected arrivals at each noriba on a map. How those positions come to be displayed at all is explained in how a bus location system works, and the background to a day when the bus fails to appear when you expect it is covered in why buses run late.

The fuel cell bus is a story about hydrogen as a fuel, and at the same time a story much closer to daily life, about a quiet cabin and a socket to plug into when the power goes out. The next time a futuristic body pulls up at your stop, raise your hand a little earlier than usual and step aboard. The quiet of moving off makes the case better than any explanation can.