Monday, June 15, 2009

BMW Hydrogen 7

Here is another innovative look at a future technology. The car is a BMW 7-series 6.0-liter V12 modified to run on both gasoline and liquid hydrogen rather than employing a hydrogen fuel-cell. The car looks like any other 7-series with the exception the engine cover. There is a switch that allows the driver to switch between the two fuel sources.

The BMW Hydrogen 7 is unlike the other Hydrogen powered vehicles. The Honda Clarity, and vehicles from General Motors, Mercedes Benz use a fuel cell technology to create electricity to power the automobile. BMW directly ignites the hydrogen directly in its standard internal combustion engine.

BMW has built 100 Hydrogen 7s, with fifty percent dedicated to customers around Berlin and most of the rest bound for Los Angeles. There is no current liquid hydrogen infrastructure so BMW has to provide a fleet of hydrogen tankers to keep the hydrogen tanks refilled.

BMW put a cryogenic tank into the trunk of the Hydrogen 7 to store the liquid hydrogen at a temperature of minus 423 degrees Fahrenheit. The tank is capable of holding 17.6 pounds of liquid hydrogen, which provides a range of approximately 125 miles. The Hydrogen 7 is also equipped with a 19.5 gallon gasoline tank. Refueling the hydrogen tank is fairly simple, with the pump hose easily attaching to the coupler on the car, behind that c-pillar door. The entire refueling process takes roughly 8 minutes.

The hydrogen fuel is stored in a large, nearly 30-gallon (110 liters), bi-layered and highly insulated tank that stores the fuel as liquid rather than as compressed gas, which BMW says offers 75% more energy per volume as a liquid than compressed gas.

One of the technical problem with the car when not using fuel, the Hydrogen 7’s hydrogen tank starts to warm and the hydrogen starts to vaporize. Once the tank’s internal pressure reaches 87 Psi, at roughly 17 hours of non-use, the tank will safely vent the building pressure. Over 10-12 days, it will completely lose the contents of the tank.


It is obvious that auto manufacturers have a ways to go before hydrogen becomes commercially feasible. It appears that Honda is the technological leader in hydrogen drivetrains.

The main concern when using liquid hydrogen is safety....since hydrogen gas is highly flammable. My concern would be a serious accident....could this turn into a replay of the Hindenberg Disaster.


  1. Peter, that is the biggest concern is the crash aspect of it. Will it be safe. Let's come up with new ways of getting around, but let's find the ones that are also safe for those driving and those around them. Thank you Peter for keeping us up to date with these things.
    Dan and Deanna "Marketing Unscrambled"

  2. Hi Dan & Deanna,

    Yes, I agree that safety is probably the most important factor in the purchasing decision. BMW will come up with a solution that will work well...the Germans have great engineers.

    Thanks for the comment!

    Pete Baca
    The Car Enthusiast Online

  3. Hi Pete .. hydrogen certainly seems to be a way for the future .. it'll be great if it can be got to work.

    This is the time (recession and all) for entrepreneurs to step out of the 'woodwork' and we'll see a lot of new technical developments soon.

    Thanks it's nice to know there are two types being developed.

    Hilary Melton-Butcher
    Positive Letters

  4. Hi Hilary,

    The auto companies are certainly working on it...since hydrogen is very plentiful, green and relatively easy to manufacture.

    Yes....this severe recession certainly will bring out new companies and entrepreneurs with new technology. The BMW hydrogen method is cheaper than the competing technology. It will be exciting to see the developements.

    Thank you for your comment!

    Pete Baca
    The Car Enthusiast Online