After pulling up to the hydrogen pump, Castillo entered a code into the pump's keypad that released the hydrogen nozzle from its holder. The filling fixture is located behind a conventional gas door, and the nozzle has to be locked onto the tank filler via a lever in its handle.
We noticed two differences from gasoline filling: First, the filling station's hydrogen compressor, behind a fence across the lane from the filling station, kicked on to bring the pressure up to the 10,000-psi standard for the Tucson. (Older hydrogen fuel-cell cars use tanks pressurized to 5,000 psi, or 35 MPa.) That took a little more than a minute.
Second, the filling nozzle itself was icy cold, though the handle attached to it was insulated. It's not dangerous, but it's different.
Because the Tucson's hydrogen tanks were about two-thirds full already, filling them to 95 percent went more slowly because the fuel had to be compressed to a higher pressure.
Still, we were in and out in the promised 10-minute window.
So how many hydrogen fueling stations are there?
In the country as a whole, there are 10, according to the U.S. Department of Energy's alternative-fuel station map.
Eight of those are in Southern California, where the first hydrogen fuel-cell cars will be rolled out--starting with the Tucson next spring--the state plans to fund up to 40 such stations by the end of next year.
We enjoyed our drive in the 2015 Hyundai Tucson Fuel Cell, though we have some reservations about its margin of power at highway speeds.
We'll put aside the question of wells-to-wheels energy use for 1 mile driven on hydrogen versus 1 mile driven on grid electricity.
For those customers who sign on the line to lease the hydrogen Hyundai, the biggest question will be: Where can I fuel it?
They'll be counted on the state of California's plans to ensure that they don't have to drive 20 miles or more out of their way to refill with hydrogen.