Automakers typically use the annual Los Angeles Auto Show to showcase their environmental technologies to officials of the California Air Resources Board, perhaps the world’s toughest emissions regulator. At the recent 2014 show, various OEMs put their latest hydrogen fuel-cell electric vehicles on stage. Clearly the FCEVs from Audi, Honda, Toyota, and Volkswagen—along with fueling-station news—dominated the “clean vehicle” space and almost made the media attendees, including Automotive Engineering, forget about hybrids.

Engineers developing FCEVs are working against overlapping regulatory clocks. By 2025MY, 15.4% of each OEM’s product mix will have to be zero-emission vehicles in order for them to sell in California and the ten other so-called Northeastern states (including D.C.) aligned with California ZEV policy. Within the ZEV rules is a provision which requires OEMs to collect credits based on the range of their battery-electrics and FCEVs. The automakers can comply with the credit rule by building the required number of ZEVs, or by buying excess credits from their competitors that have exceeded their own baseline numbers.

Honda, for example, has been purchasing ZEV credits from Tesla and is “banking” them until it produces sufficient volumes of its Fit EV and the new FCEV coming in 2016. To help ease the ramp-up burden until 2017, OEMs are allowed to “travel” credits for ZEVs sold in California in a sales-proportional basis to the Northeastern states, since the Golden State already has a lead in this area and is installing battery-charging and hydrogen refueling stations at a much faster pace than the other ZEV states.

OEM collaborations

After 2017, however, the travel policy expires for battery-electrics—but not for FCEVs. OEMs are permitted to travel their sales-proportional credits for FCEVs through 2025. Thus the heightened focus on hydrogen, storage-tank design, proton-exchange membrane stacks, and systems engineering in this field.

General Motors, Honda, Hyundai, Mercedes-Benz, and Toyota pledge they’ll have FCEVs for retail sale before 2020. Collaborations are taking some of the sting out of development time and costs; GM and Honda have a long-term program that includes hydrogen storage. Daimler, Ford, and Renault-Nissan are working together—“The relationships are strong and we’re on schedule,” reported Ford VP of Global Product Development Raj Nair. So are BMW and Toyota—the latter bringing high-pressure tank development in house after discovering hairline cracks in a prototype tank supplied by Quantum, according to an engineer involved with the program.

Following Hyundai's U.S. launch of the Tucson FCEV last spring comes Toyota’s Mirai, capable of a claimed 300-mi (500-km) range on a tank of hydrogen, refueling in less than five minutes (see http://articles.sae.org/13707/). To support Mirai’s North American debut in 2016, Toyota is collaborating with Air Liquide to develop and supply a phased network of 12 hydrogen stations targeted for New York, New Jersey, Massachusetts, Connecticut, and Rhode Island. These will serve as the foundation of a hydrogen highway for the Northeastern states. All the other hydrogen station deployments announced to date have been in California.

Specific-power advances

Audi at the L.A. show revealed an experimental FCEV/PHEV version of the A7 Sportback. With a claimed 310-mi (500-km) driving range, the car's powertrain is rated at 170 kW and offers AWD via a rear-mounted electric motor. Stablemate Volkswagen presented the Golf SportWagen HyMotion research vehicle with a similar fuel-cell power unit as the Audi’s. The front-wheel-drive SportWagen HyMotion accelerates from 0 to 100 kph (62 mph) in a claimed 10 s. Hydrogen gas is stored in four CFRP tanks located in the underbody. Their fuel capacity enables a driving range of 500 km; a refill takes about three minutes.

The Honda FCV Concept, apparently a pre-production model of Honda's upcoming production FCEV, debuted earlier in Japan but was also present in L.A. Honda's next-generation Clarity FCEV launching in 2016 applies a fuel-cell powertrain that fits completely within the front engine compartment of the vehicle.

Significant advancements to the fuel-cell stack have yielded more than 100 kW of output. Power density is increased to 3.1 kW·L; Honda claims that is an increase of 60% while stack size is reduced 33% compared to the incumbent FCX Clarity. The 2016 vehicle will have a driving range of more than 300 mi (500 km) with a refueling time of three to five minutes at a pressure of 70 MPa (10 ksi).

The cars still need a fueling infrastructure to make them convenient to use. At the L.A. show, Honda pledged $13.8 million in financial assistance to FirstElement Fuel, a California-based hydrogen fuel-station developer headed by former Hyundai and General Motors marketing chief Joel Ewanick. Earlier this year FirstElement received an additional $27 million in grants from the California Energy Commission to construct 19 stations. The state, which requires 33% of all hydrogen produced in the state to come from renewable sources, aims to have 100 vehicle fueling stations built by 2024.

By comparison, the U.S. has more than 8700 public EV charging stations, according to the U.S. Department of Energy.