The other day, I was watching some media puff piece on global warming that was trumpeting hydrogen fuel cell cars as a way of reducing carbon emissions, since hydrogen cars don’t emit any greenhouse gases. Which made me laugh at the utter incompetence and ignorance of mass media. Anyway, Joseph Romm writing on Technology Review’s blog has a brutal takedown of the media’s absurd fascination with hydrogen fuel cell technology (emphasis added),
Most egregious: where, exactly, does the Times think hydrogen comes from? Santa Claus? More than 95 percent of U.S. hydrogen is made from natural gas, so running a car on hydrogen doesn’t reduce net carbon dioxide emissions compared with a hybrid like the Prius running on gasoline. Okay, you say, can’t hydrogen be made from carbon-free sources of power, like wind energy or nuclear? Sure, but so can electricity for electric cars. And this gets to the heart of why hydrogen cars would be the last car you would ever want to buy: they are wildly inefficient compared with electric cars.
Electric cars–and plug-in hybrid cars–have an enormous advantage over hydrogen fuel-cell vehicles in utilizing low-carbon electricity. That is because of the inherent inefficiency of the entire hydrogen fueling process, from generating the hydrogen with that electricity to transporting this diffuse gas long distances, getting the hydrogen in the car, and then running it through a fuel cell–all for the purpose of converting the hydrogen back into electricity to drive the same exact electric motor you’ll find in an electric car.
The total power-plant-to-wheels efficiency with which a hydrogen fuel-cell vehicle is likely to utilize low-carbon electricity is 20 to 25 percent–and the process requires purchasing several expensive pieces of hardware, including the electrolyzer and delivery infrastructure. The total efficiency of simply charging an onboard battery with the original low-carbon electricity, and then discharging the battery to run the electric motor in an electric car or plug-in, however, is 75 to 80 percent. That is, an electric car will travel three to four times farther on a kilowatt-hour of renewable or nuclear power than a hydrogen fuel-cell vehicle will.
Ouch.
