Running on Water: The BMW H7

It was a rainy day in Singapore just a few weeks ago as BMW presented its Hydrogen 7 Series cars to the public. Media from across the Southeast Asian region got a chauffeured ride along the busy city streets of the City State, which started and ended at a specially built glass-and-steel pavilion located at the corner of Beach and Ophir roads.

The weather was an apt reminder of how far BMW has come on its development of a hydrogen-powered car. Unlike conventional petrol automobiles that combust harmful carbon monoxide into the atmosphere, the BMW H7 emits only water vapor out of its exhaust. If there was any doubt cast upon the German car company in making an environmentally friendly product, one should better cast them aside. The H7 is not an experimental model, nor is it a concept car that lives and dies at the motor show floor. BMW built this machine ready to go and is a fully functional production vehicle.

Hydrogen is one of the most prominent elements on Earth and is the simplest element in the universe. One of the most common sources of hydrogen? Water – and we have lots of it. Oceans full of it, to be exact. Anyone who’s done basic high school chemistry knows that through a process known as electrolysis, running an electrical current through water, both hydrogen and oxygen molecules separate. It is in this separation that hydrogen gases are collected.

Based off of the familiar BMW 7 series, the H7 looks like any other car from the company – which only adds to the “WOW” factor of this particular vehicle. It looks like any production car simply because it is. Driving it, the only thing you’ll see different is a button on the steering wheel marked “H2”. Pushing this button seamlessly switches the car from petrol to hydrogen mode. No stops, no elaborate steps before making the change. All you’ll hear is a muffled “click” coming from the back.

The H7 uses a V12-cylinder engine with a capacity of 5972 cc. With an output of 191 kW, the H7 has a top speed of 230 kph and can go from 0-100 kph in 9.5 seconds. For practicality’s sake, the H7 makes use of not only hydrogen fuel, but petrol as well (for now). The reason for this will be explained later. Each fuel “mode” has its appropriate mileage, with a combined distance of 700 kilometers. On hydrogen mode, the H7 can go as far as 200 kilometers. When on petrol, the car reaches 500 kilometers before refueling. On hydrogen mode, the only emission out of the exhaust pipe is distilled water vapor.

The reason behind having two fuel sources is simple. Most countries do not have the necessary infrastructure to support a hydrogen economy. So, in order for the H7 to remain practical in today’s world, a regular petrol tank is still present inside the car. Even with that, the H7 is already considered to be two and a half generations ahead of any other car out there ­– and 20 years ahead of its time.

Choosing a regular 7 series car to undergo this modification of sorts was an easy one. The 12-cylinder 760i engine has a slew of innovations such as VANOS camshaft adjustment, Valvetronic variable valve drive, and petrol injected directly into the cylinder. This became the basis for a powertrain that is able to use two different fuels.

The two tanks for hydrogen and petrol are situated at the back of the car. The upper tank holds about eight kilograms of liquid hydrogen and the lower one can hold 74 liters of petrol. Fuel consumption runs from 3.6 kilograms per 100 kilometers for hydrogen, and 13.9 liters for every 100 kilometers for petrol. Refueling the hydrogen tank takes just about the same time as any regular petrol tank, about eight minutes to be exact. The two tanks have separate filler pipes, with the hydrogen one chilled to -250ºC. It is at this temperature that hydrogen becomes liquid.

The hydrogen tank is remarkable as well. Cooled to -250ºC to maintain hydrogen’s liquid state, it is comprised of an inner and outer tank connected by carbon-fiber composite material. A vacuum is present in the space between the two tanks with the inner tank encased in 40 thin layers of aluminum foil. The insulation is equal to a Styrofoam jacket that is 17 meters thick in diameter. To put this insulation into perspective, if the H7 tank contained a frozen block of water, it would take 13 years for it to melt completely. Place a cup of boiling coffee inside and it would take upwards of 80 days before it becomes cool enough to drink.

BMW has said that hydrogen fueled cars is the definitive direction the company is taking in the years to come. It is an exciting and bold venture that one major car company has embarked upon, which we hope others may follow.

For more, log on to www.bmw-cleanenergy.com.