Lots of Hot Air About Hydrogen

WASHINGTON — Earlier this month, the South Coast Air Quality Management District approved a $4-million program to put a mustache on the Mona Lisa -- at least that's how it seems to me. What the agency actually did was approve spending millions to take 35 or so of the greenest, most energy-efficient sedans ever made -- the hybrid gasoline-electric Toyota Prius -- and turn them all into dirty energy guzzlers.

It is going to achieve this giant leap backward by converting the hybrids to run on hydrogen, the most overhyped alternative fuel since methyl tertiary-butyl ether, or MTBE.

Hybrids are already extremely efficient. The Prius, for example, generates only about 210 grams of carbon dioxide -- the principal heat-trapping gas that causes global warming -- per mile. The car is also a partial zero-emission vehicle, which means that when it uses California's low-sulfur gasoline, it produces very little of the smog-forming pollutants, like nitrogen oxides.

Hydrogen is not a primary fuel, like oil, that we can drill for. It is bound up tightly in molecules of water, or hydrocarbons like natural gas. A great deal of energy must be used to unbind it -- something the AQMD plans to do by electrolyzing water into its constituents: hydrogen and oxygen. And because the resulting hydrogen is a gas, additional energy must be used to compress it to very high pressures to put it in the tank of your car.

With all the energy needed to create and compress that hydrogen -- even with the relatively clean electric grid of California -- a Prius running on hydrogen would result in twice as much greenhouse gas emissions per mile as an unmodified car. It would result in more than four times as much nitrogen oxides per mile.

I own a Prius, so that's the hybrid I am most familiar with. But Honda also makes a hybrid vehicle, and thanks to California's leadership in vehicle emissions regulations, many other car companies plan to introduce them soon. These cars will get even greener over time as technology improves.

Sadly, two of the features I love most about my car would be wiped out by the AQMD's expensive "upgrade." First, the hybrid has cut my annual fuel bill by half. Hydrogen is so expensive to make that even with California's high gasoline prices, the hydrogen hybrid will have more than four times the annual fuel bill of a gasoline hybrid. Second, my car can go twice as far on a tank of gas as my old Saturn, so I have to make those unpleasant trips to the gas station only half as often. The hydrogen hybrid would have less than half the range of my car. With hydrogen fueling stations so scarce, hydrogen hybrid drivers will constantly be scampering back to the fueling stations before the tanks get too low.