Honda has revealed the next-generation of its Clarity Fuel Cell sedan at the 2015 Tokyo Motor Show. While it represents the company's latest hydrogen fuel cell (HFC) developments, the Clarity Fuel Cell is in many ways more like your everyday car than any HFC has ever been before.
Until now, most HFC vehicles have been converting hydrogen to electricity in complex systems that often take up valuable passenger or cargo space in the car. The hydrogen (H2) storage cylinders used in these vehicles can be bulky, as can the fuel cell stacks themselves. Further, the refueling process, while faster than re-charging a large battery, has usually been relatively slow when compared to pumping gasoline.
The Clarity Fuel Cell changes that, Honda says. The new Clarity is a standard five-seat midsize sedan with all of the room and versatility that buyers in the segment expect. This despite being capable of carrying enough H2 to propel it for up to 700 km and requiring only three minutes to fill at a refueling station.
It begins with the new exterior design of the car. A slightly larger, wider vehicle than its predecessor, the new Clarity also drops many of the previous-generation’s overdone futuristic styling cues. It keeps enough of them to remain recognizable for what it is, but the over-the-top front fascia and rear wheel skirts are now gone. They’ve been replaced by a bold, but still contemporary styling that remains dramatic without being overpowering.
Inside, the Clarity Fuel Cell has a modern, spacious appeal. The dashboard is lifted and pushed back, a common theme in today’s sedans, and the use of color and tone as well as sharp-angled, thin pillars opens up the interior. Of note here are the large information screen at the center of the dashboard, the much-diminished center console for improved legroom, and the extensive use of glass for an airy appeal.
Adding to this interior feel is the smart seating arrangement, built around the powertrain’s requirements. The front seats are low and sit atop the battery pack. The rear seating sits higher, giving more legroom and a better view, though it does likely infringe on headroom. This accommodates the hydrogen storage tanks beneath, occupying the space where the gasoline fuel tank in a traditional automobile would normally be.
This means that the trunk space is not compromised by extra hydrogen storage (a second tank sits where the rear axle would normally be) and the fuel cell stack and motors that power the car are located under the hood instead of in the center of the car. This allows a balance of weight distribution as well.
This design is possible because of several upgrades to the hydrogen fuel cell technology involved. The new fuel cell stack is much smaller and more power dense than it was before, giving up to 100 or more kilowatts of output. Its density is rated at 3.1 kW per liter. That’s a 33 percent reduction in size compared to the outgoing generation of the Clarity, Honda says.
The hydrogen fuel used in the stack is stored at 70 MPa (10,153 psi) and the total storage capacity within the Clarity Fuel Cell gives the car a range of over 700 kilometers (435 miles). Fueling time is about three minutes from empty. These metrics make it equivalent to most gasoline vehicles of the same size.
In driving, though, Honda says that the Clarity Fuel Cell is much sportier than its gasoline rivals. Its high output motor can deliver up to 130 kW (174 hp) of power to the drive wheels and because it has no need for gearing, torque is at maximum at all times without any jerky gear shifts. Throttle response is unimpeded by fuel delivery and burning requirements, making it nearly instantaneous. A driver-selectable two-mode system allows for Normal driving, balancing performance and economy, and Sport, which prioritizes acceleration.
In emergency need situations, the Clarity Fuel Cell and its on-board hydrogen and fuel cell stack can be utilized as an emergency generator. A lightweight external power supply not unlike a standard generator can be employed for this. The Power Exporter 9000 takes the Clarity’s power output and converts it to usable standard AC power for a home or office. According to Honda, a fully-fueled Clarity could power the average home for about a week.Honda says that the technologies seen in the Clarity Fuel Cell will proliferate to other vehicles in their lineup over time. The system is compact enough and modular enough to be used with most vehicle platforms. The new-generation Clarity Fuel Cell will be commercially available in select markets soon.