In addition to hydrogen, Toyota is looking at several other fuel sources, including natural gas, methanol and a relatively new concept called CHF, or clean hydrocarbon fuel. CHF, which can be made from petroleum or other resources such as natural gas and coal, will also work in current gasoline-powered cars.
"It's not a matter of one fuel winning and the other losing," Nakamura said, "it's a matter of coexistence."
As petroleum resources become increasingly scarce in the years ahead, Nakamura predicts that "fuel cell vehicles will be the majority of automobiles in use." Although many improvements must be made by all manufacturers before mass marketing is feasible, Toyota's FCHV-4 is a good indication of what fuel cell vehicles may be like.
Based on the five-passenger Highlander, it features a proprietary high-output 90-kilowatt Toyota FC Stack, which is no larger than a conventional gasoline engine. The fuel cell stack also works in tandem with a secondary nickel-metal hydride battery to give the vehicle regenerative braking and other attributes derived from its unique hybrid system.
It has a top speed of nearly 95 mph and a cruising range of more than 155 miles. In addition, Toyota engineers succeeded in giving the FCHV-4 three times the vehicle efficiency of an ordinary gasoline-powered car. Under the rear cargo deck, there are four high-pressure hydrogen storage tanks. Each tank has a maximum storage pressure of 3,600 PSI (25 MPa), which Toyota hopes to increase for improved cruising range.