Driving into the future

BERLIN — The need for zero-emission cars will be growing in the future and some alternatives to fossil fuel have been around for a considerable time now.

One of the options is the electric car, but the use of heavy batteries that cannot be recycled does not seem to be very realistic.

Another solution is the fuel cell and while several car manufacturers have been looking into this technology for some time, the odds are that a fuel-cell car will not go into mass production before 2025 at the earliest.

BMW is taking a somewhat different route and has built its first small series of bi-fuel cars. In this case, bi-fuel does not mean that the engine can run on gasoline and on E85 (the combination of gasoline with 85 percent ethanol), but the BMW powertrain can either run on gasoline or hydrogen, hence the name for the 7-Series sedan: Hydrogen 7.

The Bavarian company is not the first one using hydrogen, as by the end of the ’60s the small German car manufacturer NSU (later taken over by Audi) built a rotary engine that used hydrogen, while a couple of years ago Mazda presented a hydrogen-powered concept of the RX8.

However, BMW is the first manufacturer that not only has developed its conventional 6.0-liter V-12 engine for the use of both gasoline or hydrogen, but also has built a fleet of 100 units.

By no means is BMW of the opinion that a bigger series can go into production anytime soon, but the company wants to show it has “reached an important milestone using the energy of the future.” And the engineers want feedback from their customers, high-end companies and individuals who will drive the exceptional 7-series in daily life and who probably will pay a fee for the lease.

Half of the 100 cars will be going to Berlin, where Aral was the first to open a hydrogen station. Total, which has teamed up with BMW for this project, also has a filling station there. The rest is for BMW’s hometown Munich, for Frankfurt, Milan, Brussels and London.

Los Angeles, Washington, D.C., Shanghai, Beijng and Tokyo will get some. For these markets BMW and Total will provide a support fleet of mobile H2 tankers.

It is nice to be part of the future, if only for a day — the day that BMW invited me for a test drive on the autobahn, the area around Berlin and through the city. Behind the wheel of the Hydrogen 7 you would not realize there is anything unusual. But the small display between the odometer and the rev counter shows an amber-colored “H,” which indicates the V-12 is running on hydrogen.

By a push of the button on the steering wheel, you can change over to normal gasoline and back. You cannot say it is flawless, as you will notice the change by a minor holdback of the engine, but if you do not pay attention, you might not feel it. Even under strong acceleration, the feeling is the same.

As simple as this changeover goes, the technology used to put the first hydrogen car on the road is just as complicated. The dual-mode combustion engine has been modified significantly to enable the use of hydrogen.

The 6-liter V-12 with Valvetronic technology has been detuned from its original 445 horsepower and 442 foot-pounds of torque to 260 horsepower and 287 foot-pounds. In this way the power output is the same for both modes and there is no power shock when you change from gasoline to hydrogen or back. But 260 horsepower from a V-12 is not shocking either.

Despite the extra weight of about 440 pounds, the car does not feel extremely heavy and is still reasonably quick, but has lost its rocket-style acceleration. Normally the 7-series goes from zero to 60 mph in only 5.5 seconds, but the H7 score is nearly 10 seconds. The top speed is limited at 145 mph.

On gasoline, the engine operates with direct fuel injection and in the hydrogen mode the fuel/air mixture is formed in the intake manifolds. Apart from the engine and electronics development, BMW had to solve the problem of storing the hydrogen. The Hydrogen 7 has two fuel tanks; the one for hydrogen takes around 45 gallons of liquid hydrogen, while its conventional gas tank has a volume of 16.3 gallons.

Together they give the H7 a range of approximately 435 miles, 125 on hydrogen and 310 on gas.

The hydrogen tank is of special construction because hydrogen under atmospheric pressure has to be cooled to minus 253 Centigrade in order to turn into a liquid. Innovative super insulation is required to store it in the car for longer periods. Therefore the hydrogen tank in the H7 has double walls with several layers of aluminum and glass-fiber between, measuring almost 1.2 inches in thickness to prevent warming of the fuel.

But also many security measures had to be taken, such as a boil-off management for controlling the inner pressure of the tank and eventually evaporation, plus the installation of five sensors that sniff odorless hydrogen in case of leaks.

We made a stop at the Total station in the outskirts of Berlin to fill up the hydrogen tank of the 7-series. First you push a button on the dashboard to open the filler cap, then you take the quite heavy refueling nozzle out of its cradle and aim it as well as possible at the filler manifold in the car. After securing, you push a button on the hydrogen station’s digital display. The system starts with a self-check, then begins filling hydrogen into the BMW. The whole process takes about eight minutes.

The clean-burning hydrogen — zero emission — requires a favor. As the hydrogen tank is quite big, it uses half of the luggage space plus some 6 to 7 inches of legroom in the rear of the long version of the 7-series.

Dr. Klaus Drager, BMW’s board member for research and development, said: “The hydrogen system is an ’add-on’ to an existing model. When we develop a new car that runs on hydrogen, we will build it around the hydrogen tank.”

Despite the fact that a hydrogen-powered fuel cell is regarded as the fuel of the future, it is not at all certain what the future will be.

The hydrogen in the BMW Hydrogen 7 engine burns cleaner than any other fuel, as it converts into water vapor, that has minor amounts of nitrogen oxides and hydrocarbons from the oil used in the engine for lubrication. But BMW says the hydrogen-powered combustion engine can be further improved and the availability of hydrogen has a long way to go. Also the safety issues has to be overcome. At the moment, certain governments do not allow hydrogen-powered cars, nor CNG-powered cars in closed parking garages.

However, with the bi-fuel 7-series, BMW is exploring a new technology and shows the world that it has built a clean car in the upper segment. That is something that will not hurt its reputation, no matter if hydrogen proves to be in our future or not.

The BMW Hydrogen 7 will make its first public appearance at the L.A. Auto Show next Wednesday.