It was the summer of 2000. The world had comfortably survived the Millennium Bug, Kylie Minogue’s “Spinning Around” was on top of the music charts in the UK, and Google had just released the first 10 language versions of Google.com in French, German, Italian, Swedish, Finnish, Spanish, Portuguese, Dutch, Norwegian and Danish. In Rotterdam, the very first production Toyota Prius hybrid to be sold in Europe reached the continent.
Prius means “to go before” – a precursor to a new era of electrified mobility. Today, the first production Toyota Mirai – meaning “the future” in Japanese – destined for the European market has arrived, and, like its elder, it is here to pioneer the next step in clean mobility, using hydrogen as fuel and emitting nothing but water vapour.
The first five Mirai cars were unloaded in Bristol, UK and Zeebrugge, Belgium, respectively on 8 and 10 August.
The Toyota Mirai is the world’s first mass-produced fuel cell sedan. After its first public display in Europe in March at the Geneva Motor Show, today marks its debut on European ground. Already sold in Japan since last December, the Toyota Mirai will be launched in Europe from September in the UK, Denmark and Germany.
With Mirai, Toyota is at the forefront of the fuel cell development thanks to our advanced engineering capabilities and our deep knowledge and experience of Hybrid technology. Mirai will allow us to grow awareness, knowledge and acceptance of the fuel cell technology and to promote the development of the required hydrogen infrastructure. It will also help us understand customer experience with the new technology, with trailblazers who want to drive the hydrogen movement forward.
Mirai uses the pioneering Toyota Fuel Cell System (TFCS), which features both fuel cell technology and hybrid technology, and includes Toyota’s new proprietary fuel cell stack and high-pressure hydrogen tanks.
Using hydrogen as fuel to generate electricity, Mirai achieves superior environment performance with no CO2 emissions or pollutants when driving, and the same level of convenience and autonomy as gasoline engine vehicles, with a generous cruising range and a hydrogen refuelling time of about three to five minutes.
This could well be the first question on your lips when you hear that our Mirai fuel cell vehicle is powered by hydrogen. Here’s our answer
The quick answer: “Most definitely YES!”
Toyota, of course, only releases a car into the market that is totally safe. The Mirai is no exception. Over the last decade, hundreds of Mirai test cars have been thoroughly road tested, crash tested and safety tested. They have racked up millions of kilometres over all sorts of demanding terrains. They have been put through their paces in the cold of northern Finland and the heat of southern Spain. Their hydrogen fuel tanks have even been shot at by high-velocity weapons.
The result? The Mirai has passed all the tests with flying colours. It’s as safe as any other Toyota vehicle. The fact that it is powered by hydrogen has absolutely no effect on its inherent safety.
The long answer
Let’s unpack the short answer to look at three aspects of a hydrogen powered car like the Mirai that relate to safety: the car, the refuelling process, and the gas itself.
THE CAR: Tough fuel tanks and highly sensitive hydrogen sensors
The hydrogen that powers the Mirai is stored at a high pressure of 700 bar in two compact, lightweight tanks. We have been working on their design in-house since 2000 and are more than satisfied with their strength and safety levels.
Their main source of strength originates from the carbon fibre shell. Over that is a glass fibre layer. Should the car be involved in an accident, any resulting damage to the hydrogen tank will be clearly visible on this layer. Tests can then be carried out to evaluate if the carbon shell itself is compromised. The glass fibre does not contribute to rigidity of the tank, but gives absolute confidence of its integrity. The whole tank is lined with plastic to seal in the hydrogen.
As mentioned above, the tanks have been subjected to extremely severe testing. They are designed to withstand up to 225% of their operating pressure, which is clearly a very comfortable safety margin.
In the improbable event of a leak, the Mirai contains highly sensitive sensors that detect minute amounts of hydrogen. These are placed in strategic locations for instantaneous detection of hydrogen. In the extremely unlikely event of a leak in the fuel system, the sensors immediately shut down the safety valves and the vehicle itself.
As a third layer of safety, the cabin is strictly separated from the hydrogen compartment to prevent penetration of any leaking hydrogen, which would instead gradually disperse into the atmosphere.
THE REFUELLING PROCESS: International safety standards in place
Refuelling is a critical process because it involves human action, which unfortunately can lead to unforeseen and unsafe scenarios, like trying to drive off while the fuel nozzle is still connected to the car. For this reason a number of safety precautions have been put in place.
First, the nozzle at the end of the hydrogen dispenser’s flexible hose contains a mechanical lock to ensure optimal connection with the car’s filling inlet. Unless this mechanical lock clicks into place securely, filling will not commence.
Secondly, a pressure impulse checks for any leakage in the system between the filling station and the car. If a leak is detected, refuelling is aborted.
Thirdly, the rate of filling is carefully regulated, to avoid overheating during transfer. Temperature sensors located in the car’s hydrogen tanks, the nozzle and the pump constantly communicate with each other by infrared to control the rate of flow of hydrogen into the car so that the temperature rise is not excessive.
The internationally applicable standards SAE J2601, SAE J2799 and ISO 17268 establish safety limits and performance requirements for gaseous hydrogen fuel dispensers. The criteria include maximum fuel temperature at the dispenser nozzle, the maximum fuel flow rate and the maximum rate of pressure increase.
By the way, if you try and drive off in your Mirai while the fuel nozzle is attached to the car, you won’t succeed! The car’s ignition is disconnected until you have replaced the nozzle in its holster and closed the car’s fuel cap. To be absolutely sure, a redundant safety system is embedded in the hose and locks the pump if a car would pull the hose too hard when driving off in the middle of refuelling.
THE GAS: Using the lightest element in the universe has its benefits
Hydrogen is the lightest thing known to man and considerably (14x) lighter than air. The consequence is that should a leak occur, the hydrogen will rise into the atmosphere. And thanks to its status as ‘’smallest molecule ‘’ in the universe, it disperses quickly in air and any gas.
The advantage of this is clearly illustrated in gunfire tests conducted on a hydrogen tank. When the hydrogen ignites it appears as a localized jet flame, which is much safer than an accumulation of gas that could suddenly explode.
Finally, the Mirai’s tanks have a pressure relief device that releases the hydrogen gradually in case the temperature should rise abnormally (like in a fire). This prevents any overpressure or explosion; far from the stereotype of a hydrogen explosion. Moreover, the resulting fire leaves much of the car undamaged.
Hydrogen is as safe as any other fuel used in a car. It’s been used as an energy carrier for decades, and there is a vast amount of cumulative know-how and experience in Toyota and elsewhere to handle it safely.
Furthermore, it is a carbon-free, non-hazardous energy source that can be produced from many renewable resources and emits no greenhouse gases when used as a fuel.
No wonder that “mirai” is a Japanese word meaning “future.”
‘Mirai’ may mean ‘Future’ in Japanese, but Toyota’s first mass production fuel cell car has origins as far back as the mid-nineties. That is when the Japanese manufacturer laid out a strategy that was aimed at guaranteeing sustainable mobility for the 21st century.
Toyota’s goal was threefold. First, to improve overall efficiency, allowing drivers to do more with less. Secondly, to diversify the energy sources used to propel cars, in order to reduce dependence on dwindling oil reserves. And finally, to reduce the environmental impact of personal mobility.
Hybrid is the cradle
To this day, the most legendary heir of that strategy is the petrol-hybrid Prius. By combining a petrol engine with an electric motor, the concept behind Prius was as simple as it was ingenious. On the one hand, the car was able to recapture energy that traditionally goes to waste under braking, and store it in a compact on-board battery. And on the other hand, this battery fed an electric motor that could step in to support the engine, reducing its thirst for fuel. Through a clever gearbox, the system allowed petrol and electric to work in perfect symbiosis, and even permitted the engine to run as often as possible in its most efficient rev-range. Any surplus power was simply turned into electricity and sent to the battery.
Seen by many at first as little more than an oddity, Prius and its powertrain gradually won fans. Technology lovers chose it for its high tech content, environmentalists for the greener form of transport that it promoted. And when the rich and famous embraced it and started selecting it over the luxury barges and supercars that they preferred in the past, awareness and appreciation rocketed.
Today, hybrid technology has found its way into various other models of the Toyota range. One in three Yaris sold in Europe today is hybrid and the same goes for 40% of all Auris. Nor is Toyota longer alone as a hybrid manufacturer: in recent years, other brands have started to follow suit – including some of the brands that had been highly critical of the technology at the beginning.
Battery electric vehicles for last mile mobility
Less well known, is that Toyota’s plans extended much further. Its strategy placed hybrid at the heart of the future car market, but it also foresaw a clear role for electric vehicles. Having invested in battery research in its own Physical and Chemical Research institute founded as far back as 1940, Toyota didn’t hold out much hope for a sudden break-through in batteries that would suddenly make EVs a valid mass-market alternative for the regular family car. However, it did see opportunities for small battery-powered vehicles as an alternative for urban, last-mile mobility. In such usage, driving range is less of a priority, so the battery pack can be kept compact and light, in itself helping efficiency. The latest personification of this concept is the Toyota i-Road, which is deployed in pilot car-sharing programmes in Japan and in the French city of Grenoble.
Fuel Cell for high mileage vehicles
At the other end of the scale, for large vehicles designed for long distance travel, Toyota started researching Fuel Cell technology. Using hydrogen as a source for on-board electricity generation yielded a very different type of electric vehicle: one that was not limited by range or by recharging time.
In the subsequent development of EVs and Fuel Cell cars, Toyota relied heavily on the architecture it had devised for its hybrid powertrains. The principle of energy recuperation was applied to both vehicle types, whereas the hybrid concept was adopted in its entirety for the Fuel Cell prototypes. Here, the petrol engine from a traditional hybrid was simply replaced by a Fuel Cell stack, and the petrol tank by hydrogen tanks.
Today, after more than fifteen years of development, Mirai’s basic architecture borrows from that of the very first Prius. And several parts of its powertrain, such as the motor and the traction battery, are proven components that are shared with other Toyota hybrids.
Going forward, Toyota Fuel Cell cars can be expected to continue to benefit from the company’s ever strengthening expertise of hybrid technology.
This week, the Motomachi-plant in Toyota City starts mass production of the Toyota Mirai fuel cell car. A historic moment for Toyota, which also underlines the expertise and the know-how off the work-force at this Toyota City based plant.
The Motomachi factory is one of the oldest in the Toyota group. Located nearby the group headquarters in Toyota City, it started operations in 1959 with the production of the legendary Toyopet Crown.
Today, the plant employs approximately 7000 workers, most of them
involved in the production of models for the Japanese market, such as the Crown and the Mark X.
But since 2008, a small unit of highly skilled employees is assigned tospecial projects that require a lot of care, acting as pioneers within Toyota’s production workforce. This is the team that built the limited-run Lexus LFA supercar, and now, they have turned their attention to the Toyota Mirai.
They have a dual role: supplying the first mass-produced fuel cell car and gathering experience for future generations of the Toyota hydrogen-powered models.
The first months of Mirai production are destined for the Japanese market, but as from summer 2015, Motomachi will also start churning out cars for Europe and the US.
The Mirai signals the start of a new age of vehicles. Using hydrogen – an important future energy source – to generate electricity, the Mirai achieves superior environmental performance with the convenience and driving pleasure expected of any car.
The Mirai uses the Toyota Fuel Cell System (TFCS), which features both fuel cell technology and hybrid technology, and includes Toyota’s new proprietary FC Stack and high-pressure hydrogen tanks. The TFCS is more energy efficient than internal combustion engines and emits no CO2 or pollutants when driven. Drivers can also expect the same level of convenience as offered by gasoline engine vehicles, with a generous cruising range and a hydrogen refuelling time of about three minutes.
Hydrogen-powered fuel cell vehicle: Toyota Mirai
The Mirai delivers everything expected from a next-generation car: an immediately recognizable design; driving exhilaration stemming from superior handling stability achieved by a low center of gravity; and quiet but powerful acceleration provided by the electric motor.
TFCS provides superior environmental performance and convenience
The Mirai features the TFCS, a fusion of fuel cell technology with hybrid technology.
The system uses Toyota-developed components including the Toyota FC Stack, FC boost converter, and high-pressure hydrogen tanks.
Toyota FC Stack
The new Toyota FC Stack achieves a maximum output of 114 kW (155 DIN hp) and a world-leading power output density of 3.1 kW/L (2.2 times higher than that of the previous Toyota FCHV-adv limited-lease model).
FC Boost Converter
A new compact, high-efficiency, high-capacity converter has been developed to boost power generated in the Toyota FC Stack to 650 volts. Increasing the voltage has made it possible to reduce the size of the electric motor and the number of Toyota FC Stack fuel cells, leading to a smaller, higher-performance Toyota Fuel Cell System, thereby reducing system costs.
High-pressure Hydrogen Tanks
Tanks with a three-layer structure made of carbon fiber-reinforced plastic and other materials are used to store hydrogen at a very high pressure of 70 MPa (70 megapascals, or approximately 700 bar). Compared to the high pressure hydrogen tanks used in the Toyota FCHV-adv model, tank storage has been increased by approximately 20 percent.
Superior handling stability and outstanding quietness enhances driving pleasure
The high output Toyota FC Stack and optimal battery power control drive the electric motor and ensure powerful responsiveness at all vehicle speeds. This provides an immediate increase in torque at the first press of the accelerator, and powerful and smooth acceleration thereafter.
Handling stability and ride comfort are both improved through the location of major parts such as the Toyota FC Stack and high pressure hydrogen tanks centrally under the floor to achieve a low centre of gravity and superior front-and-rear weight distribution, as well as the use of a high-rigidity body, which features enhanced rigidity around the rear suspension.
Impressive driving dynamics
The full under-floor cover and aerodynamically designed clearance lights reduce wind resistance and contribute to improved fuel efficiency and handling stability. Aero fins employed at the side of the rear combination lamps also improve straight-driving stability.
Outstanding quietness is achieved by electric motor drive at all speeds and reduced wind noise, plus full sealing of all body parts, and the use of sound-absorbing and sound-blocking materials optimally arranged around the cabin, including the use of noise-reducing glass for the windshield and all door windows.
The brake support mode makes efficient use of regenerative braking and improves braking performance when the driver wishes to greatly reduce vehicle speed such as when negotiating long downhill sections of road.
Mirai Main Vehicle Specifications
||Toyota FC Stack
||Polymer electrolyte fuel cell
|Volume power density
||114 kW (155 DIN hp)
||Internal circulation (humidifier-less)
|High-pressure hydrogen tank
||Number of tanks
|Nominal working pressure
||70 MPa (approx. 700 bar)
|Tank storage density
|Tank internal volume
||122.4 liters (front tank: 60.0 liters; rear tank: 62.4 liters)
||AC synchronous electric generator
||113 kW (154 DIN hp)
|Dimensions, weight and roominess
|Minimum ground clearance
Wacth our Mirai video on YouTube for more details.
Powering the future
A few seconds before the cloth falls down
We consider fuel cell to be a key technology to future mobility – and on our stand at Paris we have another showstopper: the Fuel Cell Sedan. After 20 years of development, our first production hydrogen car, the Fuel Cell Sedan will be coming to Europe in the summer of 2015, initially available in the UK, Germany and Denmark.