Tuesday, August 4, 2009

Why the Hydrogen Myth is Bait and Switch.

Hydrogen cars are everywhere these days. Autoblog Green has been talking about BMW's Hydrogen 7 car for years while Jay Leno has spoken at length about hydrogen cars on his Green Garage portion on the Popular Mechanics website. Even California governor Arnold Scwartzenneger has converted one of his many HUMMERs into a hydrogen vehicle-- to much fanfare.

I'm hopping into the hydrogen auto conversation now because I just saw a Top Gear (Episode 102, 14 December 2008) episode in which Jeremy Clarkson hammers out the Tesla Roadster's faults while all but giggling with excitement at James May's praise of the Honda FCX/Clarity. Consequently, May heads over to Jay Leno's garage and Leno, an advocate of hydrogen vehicles based on internal combustion engines (ICE), seems to forget that James May's vehicle is a electric motor fuel-cell powered auto; a totally different technology that Jay Leno is...not a fan of (read paragraph 3).

More than a small section of a website or a governor pushing a political stunt, Top Gear is a tour de force when it comes to promoting the auto industry to the average viewer. And while there's a long list of complaints concerning what seems to be blatant eco-unfriendliness of Jeremy Clarkson, the show's main host, this episode adds a level of obfuscation to the hydrogen powered vehicle that needs to be addressed in clear and simple terms. To that end this article will lay out several points concerning hydrogen powered vehicles and their failings...which Top Gear's journalistic integrity seems to have forgotten.

  1. Bait: Hydrogen is the most abundant fuel in the universe.

    • Switch: Hydrogen gas does not appear here on Earth in any easily harnessed gaseous form. Electricity is needed to separate it from whatever compound it's found in (usually water, H2O), so that it can be burned, creating... water. That process takes energy...conventional, dirty energy. In England, where the show is taped, that energy, in the form of electricity, likely comes from a coal-fired powerplant.

  2. Bait: Hydrogen cars run on Hydrogen, a gas found in abundance all over the Universe.

    • Switch: Hydrogen cars run on h2, a liquid, compressed form of Hydrogen, which is a substance that doesn't occur naturally on Earth, so we use conventional, dirty, manufacturing processes to create it, and keep it cool in order to maintain it. At least with gasoline, you pour it in a tank underneath the fill-up station and it sits there without the refridgerator having to be on...eating more dirty energy.

  3. Bait: Hydrogen cars are more energy efficient than gasoline/diesel powered cars.

    • Switch: Well that depends on which type of Hydrogen cars you're talking about. There are two:

    Putting aside the energy it takes to make the Hydrogen available for these vehicles, the Honda fuel cell vehicle would is more efficient than a typical gasoline/diesel fueled car that uses an internal combustion engine. It's even more efficient than a Hybrid like the Toyota Prius (non-plug-in).

    The BMW, Hydrogen fueled internal combustion powered Hydrogen car, however, is less fuel efficient than the average gasoline/diesel cars of today.

    Now to be fair, one of the arguments about Hydrogen is that it's so plentiful that fuel economy matters much less...we're not going to run out of it. But that's Bait-- consult the above to remember what it takes to get the Hydrogen fuel into the car. Unless all of our Hydrogen production moves to solar or algae power very quickly, fuel economy is still going to matter.

    Let's get into WHY one type of Hydrogen fueled car is more efficient than the other, where efficiency is based on the how much of the energy in the fuel is used to propel the car forward on the road, and not much is lost to heat.

    • Hydrogen fuel cell cars are essentially designed like the proposed Chevy Volt, but without the plug-in capability. They are battery electric vehicles that use an electric motor to propel the car down the road. The motor gets its power from batteries and those batteries are, in turn, powered by the hydrogen within the fuel cell. The efficiency of the energy transfer between the hydrogen fuel and the battery system in Honda's FCX/Clarity car is 60%. There's a second step though, where that battery power is transfered to the electric motor to propel the car forward. While we don't have the data of Honda's car specifically, the average efficiency of a brushless DC motor is 85-90% with a high-end electric car like the Tesla Roadster achieving an average of 92% and a 2009 experiment at Tokai University in Japan bringing that battery-to-motor electricity energy transfer up to 96%. The reason for this is that electric motors do not idle. When you brake to a stop in an electric car, no energy is consumed until you press the "gas" pedal again to move on. In fact, some electric motors use the braking in order to put some energy back into the batteries.

      All told, if we're conservative and use the low numbers, we get 55% (60% from fuel to battery, and then -15% from battery to motor) efficiency for the fuel cell vehicle.

    • The Hydrogen 7 car by BMW is far less fuel efficient than its fuel cell counterpart. The car has the spectacular advantage of can run on gasoline at a rate of 16.9 mpg and Hydrogen fuel at a rate of 4.7mpg. The average internal combustion engine has an efficiency of 18-21%. The reasons behind this have to do with the fact that the engine idles when the vehicle is stopped, burning fuel when the vehicle's not in motion, and because the combustion of fuel to propel the vehicle creates heat in addition to motion. The low mileage of the BMW Hydrogen 7's V-12 engine means that the space within the vehicle allocated to hold the fuel is huge compared to normal cars.

  4. Bait: Filling up with Hydrogen is just as practical as filling up with gasoline: you pull up to a station, plug in the hydrogen pump, and then drive wherever you want.

    • Switch: Hydrogen leaks. It's not as dangerous as a gasoline leak because Hydrogen's a gas that just evaporates harmlessly into the air above instead of leaving a puddle of flammable substance in your garage or driveway, but non-the less, leaking presents its own problems. According to Wired, "the double-walled, stainless-steel tank that stores the liquid in high-vacuum conditions with aluminum reflective foil, the liquid hydrogen in the 8-kilogram fuel tank begins to boil after 17 hours if the car remains parked. The tank empties completely after 10 to 12 days." This is a problem if you're paying for Hydrogen...and don't have a pump in your garage or driveway.

Hydrogen isn't all that it's cracked up to be. As noted above, right now we really only have nasty ways to make it, and have to spend a fortune in fossil fuels to keep it in the proper compressed state in order to run our vehicles on it. The fuel cells currently require vast amounts of precious metals like platinum in order to work, making the vehicles prohibitively expensive. When you add the fact that it tends to leak out of the gas tanks of parked cars, forcing the owner to either buy more Hydrogen or get the stuff pumped and or manufactured at home, it's a real hassle at least, and is certainly not at all the silver bullet gearheads like Leno and the Top Gear hosts would have their audiences believe.

The auto industry, along with the oil producers who own vast quantities of their stock, continually harp on straight battery-electric cars as worthless and impractical, despite their out of the box ease of use and practical charging solutions (i.e. at home while you sleep at night) in favour of Hydrogen vehicles that are truly far away from practical production, and that don't offer a real, carbon emissions savings alternative. What's their motivation? Change-- or the lack thereof. Keeping the status quo while promising wonderful technology from the far off future is a way for them to continue to make profits from their product (on the Oil side) and to save vast amounts of money by not retooling (on the Auto Industry side). Strait battery electric vehicles represent a disruptive innovation to the production line that fills the wallets of these companies. Lucky for them, their rhetoric sells since people, on average, don't want to change their lifestyles to cope with a problem they don't yet have direct contact with.

In the battle to curb harmful emissions while maintaining our lifestyles, we have to remember that sadly, these emissions are part of our lifestyles. One cannot change while the other remains the same. Thankfully , there's hope. Innovations in battery-electric cars have lead to new vehicles with more performance, less range limitations and vastly shorter charge-up times. But that's the stuff for a separate blog post.

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