With all the attention to electric cars, I figure that we’re either at the dawn of electric propulsion vehicles or of electric propulsion vehicle hype. Elon Musk’s Tesla motor car company stock is now valued at $59 B, more than GM or Ford despite the company having massive losses and few cars. The valuation, I suspect, has to do with the future and autonomous vehicles. There are many who expect self-driving vehicles will rule the road, but the form is uncertain. In this space, i suspect that hydrogen-battery hybrids make more sense than batteries alone, and that the first large-impact uses will be trucks and busses — vehicles that go long distance on highways.
Currently there are only two bands of autonomous vehicles available in the US, the Cadillac CT6, a gasoline powered car, and the Tesla. Neither work well except on highways because the number of highway problems are fewer than the number of city problems and only the CT6 allows you to take your hands off the wheel — see review here. To me, being able to take your hand off the wheel is the only real point of autonomous control, and if one can only do this only on the highway, that’s acceptable. Highway driving gets quite tiring after the first hundred miles or so, and any relief is welcome.
Tesla’s battery cars allow for some auto-driving on the highway, but you can’t take your hand off the wheel or the car stops. That battery cars compete at all for highway driving, I suspect, is only possible because the US government highly subsidizes the battery cost. Musk then hides the true cost among the corporate losses. Without this, hydrogen – fuel cell vehicles would be cheaper, I suspect, while providing better range, see my calculation here. Adding to the advantage of hydrogen over batteries, the charge time for hydrogen is much faster. Slow charge times are a real drawback for highway vehicles traveling any significant distances. While hydrogen fuel isn’t cheap — it’s becoming cheaper and is now about double the price of gasoline on a per mile basis. The advantage over gasoline is it provides pollution-free, electric propulsion, and this is well suited to driverless vehicles. Both gasoline and battery vehicles can have odd acceleration issues, e.g. when the gasoline gets wet, or the battery gets run down. And it’s not like there are no hydrogen fueling stations. Hydrogen, fuel-cell power has become a major competitor for fork-lifts, and has recently had its ten million refueling in that application. The same fueling stations that serve the larger fork-lift users could serve the self-driving truck and bus market.
For round the town use, hydrogen vehicles could still use batteries, and the combined vehicle can have very impressive performance. A Dutch company has begun to sell kits to convert Tesla model S autos to combined battery + hydrogen. With these kits, they boast a 620 mile (1000 km) range instead of the normal 240 miles. See the product here. On the horizon, in the self-driving fuel cell market, Hyundai has debuted the “Nexo” with a range of 370 miles. Showing off the self-driving capability, Nexos were used to carry spectators between venues at the Pyongyang olympics. Japanese competitors, the Toyota Mirai (312 miles) and the Honda Clarity Fuel Cell (366 miles) can be expected to provide similar capabilities.
The reason I believe in hydrogen Trucks and Busses more than cars is the difficulty of refueling, Southern California has installed some 36 public hydrogen refueling stations at last count, but that’s too few for most personal car use. Other states have even fewer spots where you can drive up and get hydrogen; Michigan has only two. This does not matter for a commercial truck or bus because they go between fixed depots and these can be fitted with hydrogen dispensers as found for forklifts. It’s possible trucks can even use the same dispensers as the forklifts. If one needs a little extra range one can add a “hydrogen Jerry can” to provide an extra kg of H2 to provide 20-30 miles of emergency range. I do not see electric vehicles working as well because the charge times are so slow, the range so modest, and the electric power needs so large. To charge a 100 kWhr battery in an hour, the charge station would have to have an electric feed of 100 kW, about as much as a typical mall. With 100A, 240 V, the most you can normally get, expect a 4 1/2 hour charge.
The real benefit for hydrogen trucks and busses is autonomy. Being able to run the route without major input from a driver. So why not gasoline, as with the Cadillac? My answer is simplicity. If you want driverless simplicity, you want electric or hydrogen. And only hydrogen provides the long-range, fast fueling to make the product worthwhile.