The plan works: give keys to new concept car (I know, I know, BMW insists this is a production model having produced 100 of them) to major celebrity. Slavering packs of paparazzi and media types, like myself, inevitably write about it, catapulting the new vehicle into the popular consciousness. Courtesy of AutoblogGreen Well, here I am following BMW's plan for their hydrogen-fueled 7 Series sedan. Having handed over the keys to the arch-rube himself Ron Burgundy, a.k.a. Will Ferrell, BMW wants to tout the awesome potential of this modified internal combustion engine. How modified? Well, it can either burn gasoline and get 14 miles per gallon in the city or burn liquid hydrogen (stored in the trunk) and get 15 miles per kilogram. Note the transition to kilograms before you get excited. By my napkin and calculator fuzzy math, which may be off, that's roughly 4 miles per gallon (although it's really hard to say how much H2 would be in a gallon. Suffice to say that BMW says it gets 32 kilowatts of energy per liter from the cryogenic fuel as well. Feel free to improve on my math in the comments.) The trade-off for that markedly reduced fuel economy? Emissions that are only water vapor, though I have yet to see anyone lining up to drink the condensation, unlike fuel cell vehicles. The other benefit of this scheme is reduced carbon dioxide emissions but the flaws are legion: the hydrogen boils off if left standing too long as it must be maintained at -253 degrees Celsius (-423 degrees Fahrenheit); the tank holds only about 120 miles worth of hydrogen driving (hence the inclusion of a standard engine as well); and you can't keep it in an enclosed space for fear that the colorless, odorless boiled off H2 will build up and explode. That is before we even get to the problem of where the heck to refuel the thing (lucky for Ferrell, California has 24 filling stations, for the entire state). And where the heck that darned hydrogen is going to come from in the first place. As many have noted: hydrogen is just an energy carrier, and not a particularly efficient one. To get it, you have to break down water or reform natural gas, both of which suck up energy and potentially lead to the emission of those dreaded greenhouse gases these cars are working so hard to avoid. If you're going to go hydrogen in California or elsewhere, why not go with a fuel cell, like the Honda FCX? (Note: Honda went the beautiful young Native American woman route for their PR stunt, though they also gave it to a model nuclear family.) By using an electric motor, it eliminates CO2 emissions from the car entirely, unlike the BMW, which, by burning the H2, manages to still squeeze out roughly 5 grams of CO2 every kilometer. That's .09 pounds per mile. A Ford version recently hit 200 miles per hour on the Bonneville Salt Flats. The German automaker claims to be concerned about the efficiency of converting hydrogen back into electricity via a fuel cell. But if you're using hydrogen in the first place that sounds like worrying about a horse that has already left the barn. To be truly more efficient, why not skip hydrogen as an energy medium all together and just use that juice? Studies have shown that the existing electric grid could handle a fleet of battery-powered automobiles (whether the battery's are good enough is another question) and that such a switch would save us CO2, even if we kept burning coal (as long as we did so more efficiently. Or captured the CO2.) Even swapping in good hybrids would help a lot; Ferrell I've heard already has one of those and, given his well-known height, if that isn't an advertisement for their spacious interior I don't know what is. So I guess I'm the rube for writing about this Ferrell-BMW hydrogen stunt (reminiscent of the Brangelina-BMW PR stunt for Ocean's 13, though Ricky Bobby apparently gets to keep his at his house. Lucky man. Pinto anyone?) But I hope they don't think they're fooling anybody. And now for something completely different: why are we trying to save CO2? To keep the Swiss from getting naked... Too late, 600 or so stripped on a glacier to highlight their rapid retreat. Insert shrinkage joke below.
The views expressed are those of the author(s) and are not necessarily those of Scientific American.