Developing the Honda Clarity Fuel Cell

Honda is no stranger to putting fuel cell vehicles on the U.S. roads. The world’s first lease of a fuel cell vehicle to a family happened in California with a model year 2005 FCX. It was followed by the 2008 FCX Clarity. And now the company is producing the 2017 Clarity Fuel Cell.

Dimensionally, the Clarity fuel cell powertrain—24.5 inches wide, 27.6 inches high and 34.1 inches long— is approximately the same size as a Honda V6 engine. Consequently, the packaging is much the same.

That arc on the lower right side is actually a vent, or duct, that creates an air curtain in front of the rear wheel in order to enhance vehicle aerodynamics.

The comparatively straight frame rails are deployed to help benefit not only safety, but to enhance driving dynamics and cabin space. Some 40 percent of the vehicle’s overall frame is made with 980-MPa and 1,500-MPa steels.

Yes, this appears to be a picture of a fuel nozzle pumping gas. And it is. But the gas is hydrogen at a nominal pressure of 70 MPa.

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A company that you probably haven’t heard of is FCSM, LLC. That’s because it hasn’t been around for very long, just since January 2017. The acronym ahead of the comma stands for “Fuel Cell System Manufacturing.” It is a joint venture between General Motors and Honda Motor Company. It is establishing a fuel cell manufacturing operation within the GM battery pack production plant in Brownstown Township, Michigan. It is expected to start production in 2020. The president of FCSM is

Suheb Haq of GM. He was previously director of GM Operational Excellence. The vice president is Tomomi Kosaka of Honda. He was president and CEO of Honda of America Mfg., Inc., which meant that he was responsible for manufacturing operations at three auto assembly plants and an engine plant in Ohio. Given the experience of both Haq and Kosaka, it seems clear that FCSM is serious about manufacturing advanced fuel cells for automotive (and potentially non-automotive) applications.

Those fuel cells aren’t going to be ready for a few years, but the people at Honda aren’t waiting. They believe that there is a need for serious CO₂ reductions, sooner rather than later. And they believe that fuel cells have the potential of having the greatest effect on environmental improvements going forward.

But they also know that getting a vehicle that is both cost-effective and appealing to consumers—to say nothing of the fact that there needs to be an infrastructure (i.e., literal “gas” stations) for refueling—is a huge challenge, one they’ve been addressing since doing basic research on fuel cells since the late 1980s. (They developed an experimental fuel-cell powered Odyssey minivan in 1998 in which the fuel cell equipment was so large that the vehicle could only accommodate one adult; it was, in actuality, a rolling chemical plant.)

On June 29, 2005, then senior vice president, American Honda automotive operations, John Mendel announced, “American Honda Motor Co. is thrilled to introduce the world's first fuel cell family,” speaking of the Spallinos of Redondo Beach, California, who took a two-year lease on a 2005 Honda FCX. They became, according to Honda, the first individual customers—as distinct from fleet customers, which Honda had been working with for three years before that—in the world to lease a fuel-cell-powered vehicle—from any company.

In 2007, Honda came out with the FCX Clarity, a four-place vehicle (the car the Spallinos had, which was based on the platform that was used for the EV PLUS vehicle that it introduced in 1996, was also a four-place vehicle.) One of the things that Kiyoshi Shimizu, chief engineer/development leader, at Honda R&D, and his team learned from customer feedback was that if you’re going to have a sedan, you’d better have seating for five. That thinking is based on a core belief that Honda has always had, which is “Man maximum, machine minimum,” meaning that whether you’re talking about a car or a factory layout, you concentrate on improving the conditions of the users first and foremost.

Shimizu and his team had another challenge in developing what was to become the 2017 Clarity Fuel Cell. While Honda executives are convinced of the overall benefit of fuel cells going forward, they also know that even with things like the Fuel Cells and Hydrogen Joint Undertaking (fch.europa.eu), which includes a variety of automakers (BMW, Daimler, Hyundai, Toyota and Honda), as well as energy companies (e.g., Shell and Total) and gas distribution companies (e.g., Air Liquide and The Linde Group), even though in the U.S. Honda, Toyota and Hyundai are investing time and resources (in some cases serious financial resources) working with governments and suppliers on creating a U.S. infrastructure, not everyone is (1) going to have access to hydrogen or (2) want a fuel cell vehicle.

So the Clarity platform was developed not only to accommodate a proton exchange membrane fuel cell stack (which is reduced in size by 33 percent compared to the previous generation), 130-kW (174-hp) AC permanent-magnet synchronous electric motor and associated electronics (all of which, as well as a fixed, single-speech, direct drive transmission and a 346-v lithium-ion battery, make up the powertrain which packages under the hood essentially in the same space that a Honda 3.5-liter V6 internal combustion engine would require); and two 70-mPa hydrogen storage tanks (one 24 liters; the other 117 liters; the efficiency of the powertrain and the on-board storage result in a range of 366 miles), but also serve as the basis for a plug-in hybrid and as a battery-electric vehicle.

Honda is nothing if not serious about electrification. It should be noted that the Clarity Fuel Cell uses hydrogen simply as a fuel: hydrogen and air go into the stack, where they’re transformed into electricity and water. The water is the exhaust and the electricity is used to power the motor. So, it is essentially an electric vehicle that you don’t plug in but simply refuel in a way that is completely analogous to refilling a gasoline-powered vehicle. And recognize that the vehicle range is also the sort of thing that would be pretty much in line with a conventional vehicle: an Accord with a V6 has an EPA combined number of 25 mpg and a 17.2-gallon fuel tank, so that’s 430 miles. An electric vehicle tends to have rather linear acceleration, meaning that as you depress the accelerator there is a consequent direct increase in speed (the top speed of the Clarity Fuel Cell is 103 mph). To make the vehicle even more appealing to those who are more interested in the sort of torque-based (the maximum torque is 221 lb-ft) quickness rather than the fuel efficiency that the hydrogen provides (the MPGe ratings are 69/67/68 city/highway/combined), they’ve created a Sport mode for even greater responsiveness.

OK. This is a highly-advanced vehicle in terms of how it is powered.

But it is also a highly-advanced vehicle in the fundamental structure. Remember that this is a platform that is going to be accommodating three different types of comparatively nontraditional powertrains, so engineering had the opportunity to go at the development in a way that is outside the bounds of traditional approaches, with a primary example being the use of ultra-high-strength steels.

For example, they are using a high-formability (l) 980-MPa steel for some of the body in white components, which is said to be the first application in the world. There is also 1,500-MPa hot-stamped steel in the body frame: the two materials account for approximately 40 percent of the frame, adding strength without loading on the mass.

In addition to which, there are a variety of other steels (780, 590, 440 and 270) used in the structure. There is extensive use of aluminum for the body panels. There is a glass-fiber reinforced polymer rear bumper beam. All in, the body-in-white mass reduction for the Clarity is approximately 15 percent of a conventional Honda midsize sedan.

The most remarkable aspect of the Clarity Fuel Cell is how much it is like an ordinary vehicle. This is not to underplay the remarkable technology, but to say just how transparently it has been executed. Realize that this is a sizable sedan, one larger than the Accord:

    2017 Clarity Fuel Cell    2017 Honda Accord Sedan
Length:    192.7 in.                           192.5 in.
Height:       58.2 in.                            57.7 in.
Width:        73.9 in.                              2.8 in.

Inside, there are full appropriate amenities—like the use of recycled or plant-derived materials for about 80 percent of the surface area, speaking to the environmental aspects of the Clarity—as well as tech like a heads-up display and Honda Sensing driver assistance technologies. The design theme for the interior is “Advanced Modern Lounge.”

The exterior design is sufficiently futuristic without going full Jetsons. According to Steve Center, vice president, Honda Environmental Business Development Office, the “alpha” customers, those who are all about being on the leading edge, want something that is distinctive but not over-the-top.

Although the number of fuel cell-powered vehicles on the roads of the U.S. is measured in the thousands—the low thousands—Honda hopes that the Clarity Fuel Cell will significantly add to those numbers. And as FCSM ramps up in the next few years, as there is an even greater number of compact but powerful fuel cell stacks, there is the possibility for even more fuel cell vehicles coming from Honda.