Electric vehicles (EVs) store energy in batteries, but starting this year, EVs that stockpile energy in hydrogen gas tanks—fuel-cell vehicles—will take to the road in small, but growing numbers.
“Fuel-cell electric vehicles will be in our future sooner than many people believe, and in much greater numbers than anyone expected,” asserted Bob Carter, Senior Vice President of Automotive Operations for Toyota Motor Sales (TMS), USA, at the recent Consumer Electronics Show (CES) in Las Vegas. Carter, flanked by the Toyota’s FCV concept, a somewhat tallish, four-door midsize sedan in electric blue, and a camouflaged engineering mule just back from a year of testing in the hottest and coldest climes of North America, confirmed that the company’s first production fuel-cell car will hit showroom floors in California in 2015.
“A fuel cell is more efficient to operate than a gasoline engine,” he said. “And it requires less fuel to travel the same distance with zero emissions, ” Carter told the CES audience, adding that long-standing affordability issues are being addressed and that it should “Stay tuned because this infrastructure thing is going to happen.” The fact is: “We don’t need a station on every corner.”
As Toyota affirmed its long-term focus on fuel-cell technology, it has become clear that at least a part of the auto industry openly shares that interest. That faction includes Hyundai, which is to unveil its fuel-cell Tucson SUV this year, Honda, which expects its next-generation FCEV in 2015, as well as Daimler, Ford, and Renault-Nissan, which each are working to bring fuel-cell models to market by 2017.
EV with no sacrifices
Later at Toyota’s CES booth, Craig Scott, National Manager for Advanced Technologies at TMS, said: “We’ve been working on fuel cells for decades, having made a significant investment along the way, and it’s great to see all the effort start to come to fruition.” He cited fuel-cell technology as a clean alternative to batteries that runs consistently, one that is easy to integrate with existing hybrid technology and one that scales well from forklifts to buses. “It’s actually very complementary with battery EVs,” Scott said.
“The reality is that a 300-mi (483-km) battery EV at a reasonable cost is not going to happen over the next 5-10 years,” he explained. “And people haven’t signed up to buy EVs in any numbers in the U.S. You might sell 40,000 or 50,000 vehicles a year, but it seems to be too big a change in lifestyle for many customers.”
“With a fuel cell, there are no trade-offs, no sacrifices,” Scott said. “Customers get an EV without giving up anything. They can drive the normal range on a tank of gas that fills up in 3 to 5 min.”
“In all our testing from summer in Death Valley in California to winter up in Yellowknife, Canada, the thing that you noticed is that it operates like a normal car,” said Jared Farnsworth, an engineer at the Advanced Powertrain Group of Toyota Engineering & Manufacturing North America.
Cost-cutting toward affordability
Marked cost reductions to the fuel cell power plant have been key to the technology’s prospects, according to the company. Toyota estimated that it has cut the cost of the fuel-cell powertrain and fuel tanks by 95%, compared to that of its original 2002 prototype, which, of course, likely cost millions of dollars, tempering the claim.
Start with the fuel cell stack, Farnsworth began. “We removed a very expensive piece of technology, the humidifier, which includes a water pump. Instead, we designed the stack so that water naturally circulates from the cathode where the water is produced to the anode to maintain water content,” he explained. The engineer noted that this was possible because Toyota has learned to measure water content by monitoring the electrical impedance of the stack to register when there is more or less water in the system and controlling it via temperature and pressure.
More cost reductions, Farnsworth said, accrue from the addition of a high-efficiency boost converter “to raise the output voltage two or three times to make the stack compatible with existing hybrid components so we can grab and share from other vehicles.” It also enables the system size and thus cost to be reduced.
The FCV looked to be a bit bigger than its predecessor the FCV-R Concept. According to the specs, it is 9 in (22.9 cm) longer, 1 in (2.5 cm) wider, and 3 in (7.6 cm) taller than a Corolla, with a bigger wheelbase. The tallness of the design derives from the need to shoehorn bulky systems into the vehicle including hydrogen fuel tanks, the fuel-cell stacks, support gear besides the normal electric motor and (hybrid) battery, power electronics, and cooling unit.
“We cut the number of hydrogen tanks from four to two while delivering the same storage and driving range,” Farnsworth said. There is a tank above the rear axle and one under the rear seat. “Together they hold about 5 kg of hydrogen fuel which gives the 300-mi range.”
The crash-tested, Type IV 10,000-psi (69-MPa) gas tanks, are wound from carbon fiber for strength, covered with impact-resistant outer layer and foam for protection, and lined with a high-density polymer inner diffusion barrier to halt leaks.
The team used fewer high power density cells in the normally space-hogging stack, which saved precious space. The FCV’s PEM (proton exchange membrane) fuel cell stack meets the company’s durability target of 10 years and 100,000 mi (161,000 km), and readily mates with existing hybrid technology, he said, and the all-important catalyst uses less costly platinum. Despite the smaller stack, total power output is around 100 kW (134 hp), leaving the FCV capable of 10-s 0-60 mph (0-97 km/h) acceleration runs, and a reported top speed of 106 mph (171 km/h).
California’s hydrogen dreams
Despite progress on the vehicle, the paltry number of available hydrogen service stations threatens to keep it at limited production levels. Even early-adopter California has only 19 hydrogen filling stations. They pump trucked-in gaseous hydrogen made from natural gas by two local plants, selling it for around $3/gal equivalent. But Scott said that the state has already approved $200 million to build about 20 new stations by 2015, a total of 40 by 2016, and as many as 100 by 2024.
Meanwhile, Toyota has partnered with the University of California, Irvine to help map out optimal locations for new fueling stations, he said. The spatial model considers data on hybrid and electric vehicle ownership, traffic patterns, population density, and so forth. The model, which assumes that owners want to be 6 min away from a station at most, produced a map that requires only 68 station sites to handle about 10,000 vehicles in the San Francisco Bay area and Silicon Valley, as well as Los Angeles, Orange, and San Diego counties.
As Carter said at the show's opening: “The issue of infrastructure is not so much about how many, but rather, location, location, location.”Continue reading »