Mirai Means “The Future”: Toyota’s Production Fuel Cell Car

Gary S. Vasilash

From the people who created the first mass-produced hybrid passenger car, the Prius, comes the first mass- produced hydrogen-powered passenger car, the Mirai. Yes, Toyota is making another big bet on the future.

Takeshi Uchiyamada is sitting at a table in a meeting room in a hotel in Newport Beach, California. It is sunny and fine outside. The fluorescent lights and slightly still air in the room are far from being as engaging. Uchiyamada looks tired. He has spent the day talking about a car. Talking about infrastructure. Talking about what he believes may be a turning point in automobility as we have long come to know it during the past 100 years of internal combustion engine dominance.

Uchiyamada knows more than a little something about those subjects. Especially about turning points.

Uchiyamada is chairman of the board, Toyota Motor Corporation. Yes, that means he has more than a little bit of credibility talking about automobiles and their future.

But there is another thing on Uchiyamada’s resume that has serious significance. In January 1994, he became project general manager of Toyota’s Vehicle Development Center 2, and chief engineer at the center two years later.

Toyota’s Vehicle Center 2 is where the Prius was developed.

Arguably, Uchiyamada is the father of the Prius, the hybrid car that has launched a global shift as carmakers ranging from Ford to Porsche are working to improve the fuel efficiency of their vehicles through hybridization.

Uchiyamada is not in Newport Beach to talk about the Prius.


He is in California to launch another car, a car that has potentially profound implica-tions. It is the Mirai.

The Mirai doesn’t run on gasoline. The Mirai runs on hydrogen.

Uchiyamada—who has a degree in applied physics—insists that this is a real car. It is not a science experiment. It is not a one-off. They are producing the vehicle in global markets in the Motomachi Plant in Toyota City.

Earlier in the day, people from the California Air Resources Board, the U.S. Dept. of Energy, Air Liquide (a provider of hydrogen refueling equipment), and the University of California-Irvine held forth on the importance of hydrogen to the transportation infrastructure, importance because when the fuel is processed on board a vehicle, there are no emissions outside of carbon dioxide.

So the question is simply this: There is the Prius. There is the Mirai. Which, does Uchiyamada think, he will look back on one day as having been more significant.

The answer might seem to be a foregone conclusion. Here it is, the day there is the international launch of the vehicle, a launch event that was also occurring the same day in Japan. Uchiyamada has traveled to the U.S. specifically to be on hand for the event, even though Jim Lentz, CEO of Toyota North America and senior manag-ing officer of Toyota Motor Corp., is on site in Newport Beach.

“Prius,” he answers.

Which brings us to Satoshi Ogiso, Managing Officer, Toyota Motor Corporation.

Ogiso says, “For all of its wizardry, its zero emissions and its bold styling Mirai needs to be, at the end of the day, a regular car.”

Which probably qualifies for some sort of award for understatement. Most regular cars don’t have a hydrogen fuel cell stack underneath their frontal sections and two 70 mPa carbon fiber storage tanks, one 62.4 liters, the other 60 liters, with a tank storage weight density of 5.7% and a maximum filling pressure of 87.5 mPA beneath the rear seat and in 
the truck.

No, that doesn’t define “regular car,” yet of that regular nature—or the 
transparency to the driver of the 
high levels of technology contained within—is what Ogiso maintains is essential to market acceptance.

Of the regularity, Ogiso adds, “That’s what made Prius a success. We believe that is what will make Mirai a success as well.”

Again, Ogiso knows more than the average person about the Prius because he was once the chief engineer at Toyota Development Center 1, the place where the hybrid 
car was developed; while there, he worked with Uchiyamada.

The two worked on the Prius for four years. And in his present job, Ogiso has been involved in the development of the Mirai (as well as other vehicles—including the next-generation Prius), a car that Uchiyamada is clearly championing.

Ogiso says that while Toyota has been working on fuel cell vehicles since 1992, and while the company developed a Highlander-based fuel cell vehicle that was launched as a limited-run test evaluation vehicle in 2008 (“It met overall automobile requirements, such as cold start and driveability”), it was in the beginning of 2009 that they decided to develop the mass-produced fuel cell vehicle, which has become the Mirai.

Ogiso joined the fuel cell team in 2009.

Chris Hostetter, group vp, Strategic Planning, Toyota Motor Sales, says that the planning for the Mirai was nothing if not strategic. And that it is something that goes back 20 years, back to the very time that the Prius was undergoing development.

“The Mirai and the Prius are industry-changing vehicles. Both are high-risk gambles, both were developed at huge expense and fully in-house, not just because we could do it, but because we should do it.”

While it is difficult to imagine that one could attribute altruistic motives to a corporation—as in the notion that vehicles that are more environmentally oriented than those conventionally available should be developed because it would be of benefit to society at large—that seems to be a driving factor behind both the Prius and the Mirai.

Hostetter added, “The same must be said about our commitment to do everything possible to kick-start the development of the hydrogen re-fueling infrastructure.

“Very simply, we cannot have the car without the stations.”

Which makes the Mirai even more of a challenge than the Prius. After all, the Prius uses gasoline. And given that there are estimated to be on the order of 120,000 gas stations in the U.S., refueling a Prius is a non-issue.

According to the U.S. Department of Energy, there are 13 public hydrogen refueling stations in the U.S. (11 of which are in California and of the total, Hostetter points out three of them are within 20 minutes of Newport Beach so it is not like there is a wide dispersement) and 40 private hydrogen refueling stations. Which makes refueling a Mirai a significant issue.

(And while Hostetter notes that there is something of a global movement in terms of backing the creation of hydrogen fueling stations, the numbers are still rather small: Germany has 15 stations now, will have 50 in 2015, and plans for 1,000 by 2020; Japan has 17 and is going to more than 100 by 2016; Korea plans to have more than 160 stations by 2020; the U.K. plans 15 stations in 2015 and 65 by 2020; Denmark is going for 15 stations by 2020. But to be fair, right now in the U.S. there are, again according to the DOE, only 784 biodiesel stations and 1,476 CNG stations, so it is not like alternatives are anything but limited).

Hostetter says that the California Energy Commission is investing $200-million in the development of new stations, adding 20 by the end of 2015 and more after that, to as many as 100.

But while those numbers, too, are small, with some 10,000 gas stations currently in operation in California, Hostetter says that it is all about location. Toyota collaborated with the University of California-Irvine’s Advanced Power and Energy Program on a spatial model for optimal fueling station location. It is called “Street.” The input includes such things as where owners of hybrids and electric vehicles live, figuring that in those locales there is probably a better likelihood that hydrogen vehicle buyers may be found. Also, it took into account the assumption that most hydrogen vehicle owners would want to be within a six-minute drive of a station.

Street determined that 68 hydro-gen refueling stations located in the San Francisco Bay area, Silicon Valley, Los Angeles, Orange County, and San Diego County could handle 10,000 fuel cell vehicles.

Toyota is providing financial support to FirstElement Fuel (firstelementfuel.com, which is coincidentally located in Newport Beach and has as its chairman and CEO Joel Ewanick, formerly of both General Motors and Hyundai) to build 19 stations in California. This is part of 28 stations that the California Energy Commission is funding with $50-million; the location of these stations will be based on Street siting.

Of course, Mirai is not a California-compliance vehicle. It will be sold elsewhere, which necessitates a build-out of infrastructure.

To that end, Toyota is partnering with Air Liquide (us.airliquide.com), an industrial gas supplier (at this point, hydrogen is still an indus-trial gas, given that it has yet to become much of a consumer product) on building 12 hydrogen stations in New York, New Jersey, Massachusetts, Connecticut, and Rhode Island.

Hostetter: “These states and locations have been strategically selected to support the greater New York and Boston areas, as well as provide the backbone of a hydrogen highway for the northeast corridor.”

The Mirai is an industry-changing vehicle as it is the first mass-produced hydrogen fuel cell vehicle that actually has a sales price: $57,500, before any tax credits. (It can also be leased for $499 per month for 36 months.)

But unlike the Prius, in order to get to volumes, not only is it a matter of making the cars in the Motomachi Plant, but also getting a sufficient number of fueling stations ready, so the challenge to Toyota is this much more than it was for the launch of the Prius. (Refueling a Mirai is quite similar to refueling a Prius or a Camry in terms of the pump and the nozzle is slightly different but not a show-stopper.)

About the Prius in relation to the Mirai: Ogiso notes, “When we started hybrid development, we decided to develop the components in house.” He explains that the knowledge gained of electric drives among designers, production engineering, and manufacturing is deep. What’s more, it is applicable, he says, “These skills are effective in developing fuel cell vehicles.”

So the fuel cell stack, the hydrogen tanks, and the boost converter were all developed by Toyota, in house. Part of this is leveraging what they know. Part of this is developing what they didn’t know. All of which positions them with the kind of internal knowhow that can pay dividends now and in the future.

In addition to which, the Mirai makes use of components that are used in the current-generation Toyota hybrids. Included are the electric motor, the power control and the main battery.

The Mirai is built on the Toyota MC front-drive platform. The MC platform, perhaps not surprisingly, is also used for the Prius. Another application is the Lexus CT200h, also a hybrid. Ogiso says that the Corolla (which falls under his purview, as well) uses the MC platform.

That said, Ogiso emphasizes that there is a difference between the Mirai and the other vehicles, one predicated in large part on the different needs to handle not only the hydrogen tanks, but the fuel cell stack. 

“The fuel cell stack frame uses lightweight and easily processed carbon fiber-reinforced plastic. This protects the stack by absorbing impact from vehicle-road interference,” Ogiso says. “All primary components are positioned under the floor and near the center of the vehicle. Since fuel cell vehicles do not emit high-temperature exhaust, the components are further protected by a complete underbody cover”—which, like the tanks and stack frame, is made of carbon fiber composites—“which also improves aerodynamics and reduces road noise.”

All of this contributes to a much more rigid structure than the other MC-based vehicles.

Ogiso adds, “Positioning the stack, tanks and other components under the floor and near the center of the vehicle has also resulted in a low center of gravity and good front-to-rear weight balance.” Which goes to the concern of ride and handling because while they wanted to engineer a car that has zero emissions, they also wanted to create one that would have comparatively spirited driving dynamics.

(OK. There is nothing to really compare the driving dynamics to as there are no other hydrogen-fueled volume production sedans rolling around. And “spirited” 
has to be considered in the context of a vehicle that has a curb weight of 4078.5 lb. and a system power output of 153 hp. It goes from 0 to 60 mph in 9.0 seconds. So the spirit is willing, but . . .)

Yes, the Mirai is powered by compressed hydrogen gas. The gas is processed with a solid polymer electrolyte fuel cell. The fuel cell has an output density of 3.1 kW/liter and a total output of 114 kW (a.k.a., 153 hp), which, Ogiso says are “among the world’s highest outputs.”

“The process of producing electricity onboard and on-demand is simple in theory . . . but took two decades in practice,” Ogiso says. “Proton-exchange membranes inside fuel cell stacks need moisture to produce electricity. Most fuel cell stacks use a humidifier. Mirai’s fuel cell stack is designed to circulate the water produced during the production of electricity and requires no humidifier; a world’s first.”

It is that sort of thinking that makes the Mirai possible.

The day that Takeshi Uchiyamada is intro-ducing the Mirai, the average price of gasoline in the U.S. is an astonishingly low $2.88 per gallon. Does this make the introduction of an all-new technology more difficult? Probably. 

But Uchiyamada says that low gasoline prices are a short-term phenomenon. “When we first decided to develop the fuel cell vehicle, we decided to focus on a mid-term agenda. Oil resources are finite and energy demand continues to grow.”

Toyota is committed to fuel cell technology. Uchiyamada states, “From time to time, on a short-term basis, we may feel bumps from outside factors, but in the long run, we believe the society will support zero emissions vehicles. Will we quit or stop if fuel costs change? No, we will never quit regardless of the short-term fluctuations.”

They’re in it for the long run.

It took Toyota 10 years, from 1997 to 2007, to sell a million hybrids on a global basis. It took just two more to sell another million. By the end of 2013, cumulative global hybrid sales were six million. Undoubtedly, there must have been some questions in Toyota City during those first 10 years. But the “bumps” didn’t deter them. Presumably, the same will be the case with the Mirai and what are likely to become its derivatives.