A popular vision of the hydrogen future often includes swoopy, silvery cars, waterfalls, and majestic Icelandic landscapes. Chances are that the reality of hydrogen mobility may be a little more prosaic--a fact evidenced by the hydrogen-fuel-cell-powered Hyundai Tucson that we took for a ride yesterday. Aside from its obligatory hydrogen-themed badging, the Tucson--which runs on an electric motors powered by two 40kW UTC fuel cells--looked from the inside and outside like any other workaday SUV. This particular car had taken time off from its regular day job as an internal mail carrier for AC Transit, in which capacity it has clocked up 15,000 miles to date.
In initial stop-and-go urban driving, the hydrogen Tucson delivered a smooth, quiet ride. Unlike those of many other manufacturers, UTC's fuel cells do not rely on a compressor for the hydrogen fuel feed, and so the whine we have experienced when driving other hydrogen cars was absent. After about 10 minutes of drive time, the hydrogen Tucson began juddering when under acceleration, a phenomenon that Hyundai technicians put down to the car's power-management system, which regulates the amount of current to the motor to ensure the car has sufficient motive power at all times.
One of the key challenges for the future of hydrogen cars using a proton-exchange membrane fuel cell (along with the minor issue of producing and distributing the fuel) is the longevity of the fuel cells themselves. Platinum, used as a catalyst for the fuel cell's cathode, has a tendency to degrade over time, typically through the creation of hydroxides in the fuel cell, which react with the platinum, rendering it ineffective. Accordingly, Hyundai, like many other auto manufacturers with hydrogen projects are not sure how long their hydrogen Tucson is going to last. But, like the other 32 cars in Hyundai's operational hydrogen fleet, it is a taste of the future in the real world of today.