Vancouver: There is a zero-emissions vehicle that doesn't use an oil-based (gasoline or diesel) fuel and it doesn't need to be plugged into an electrical outlet.

This vehicle runs on a fuel that can be first extracted from water and it returns to water as you drive. That's the truly amazing promise of the fuel-cell vehicle that runs on hydrogen gas.

A fuel cell generates electricity in a chemical reaction between hydrogen and oxygen and its only by-product is pure water.

Even though Honda has hybrid vehicles and is working on bringing plug-in hybrids and full electric vehicles to market in the near future, it still views fuel-cell technology as the ultimate in sustainable transportation. And the Honda FCX Clarity is its first on-the-road limited production fuel-cell vehicle.

While in Los Angeles last week at the auto show, I also got a short drive in the Mercedes-Benz B-Class F-Cell, another fuel-cell vehicle. Its hydrogen is stored at 10,000 psi in a three-tank system under the rear floor. Two hundred of these vehicles went on the road and are in the hands of customers this year in selected European markets. Full production is expected in 2015.

The technology for the B-Class F-Cell drive system is actually based on a fuel-cell stack developed by Vancouver-based AFCC Automotive Fuel Cell Cooperation.

It operates similar to a hybrid drive system, consumes the equivalent of 3.3 L/100 km of fuel and the energy not required for driving the car is stored in a lithium-ion battery.

The FCX Clarity is roughly the same size as the Honda Accord. It can seat four people and has a decent (14 cu. ft) trunk. A single tank, 5,000-psi hydrogen system allows a driving range of 386 kilometres on a fill, which is about the same as the F-Cell. And both offer far longer range than a battery-electric car can go (typically about 150 km) on a single charge.

The FCX Clarity is twice as fuel efficient as even the best hybrid powered vehicle on the market, according to Honda engineer Ryan Harty, who is sold on the benefits of this technology.

It's also as clean-running as a battery-powered electric car charged on a clean electrical grid, even if it's running on hydrogen derived from natural gas.

The fuel cell continues to shrink in size as its power output increases with each new generation. The fuel-cell stack in FCX Clarity is small enough to fit between the driver and front passenger (under the armrest) and its output is 100 kilowatts. The hydrogen fuel tank is situated behind the rear seat and under it is a lithium ion storage battery. An electric motor (136 horsepower) drives the front wheels.

FCX Clarity and the F-Cell drive like electric vehicles (which they are); very quiet in operation, with good off-the-line jump.

There's a short delay on startup and full power output from the fuel cell may take a few minutes at cold ambient temperatures.

They will apparently start at temperatures even as low as -30 degrees Celsius.

Behind what looks like a conventional fuel fill door is a high-pressure connection for the hydrogen tank. It takes about three to five minutes to fill the tank and it can be done by an owner. That's not much longer than a gasoline fill and far less than it takes to re-charge a battery.

While the clean-power promise of a hydrogen fuel-cell vehicle is great -where do you get hydrogen? It's an ongoing and seemingly endless 'chicken-and-egg' debate around fuel cell vehicles and hydrogen filling stations ... which comes first?

Honda, Mercedes-Benz and other manufacturers are working with fuel suppliers and the state of California to develop a network of hydrogen refuelling stations. The idea is to focus fuel-cell vehicle sales and the stations in key areas and then gradually expand the network of stations.

The sources of hydrogen gas are many and varied, which is part of its attraction as a fuel. Hydrogen is sometimes vented off as a waste by-product of industry, including wood pulp mills. It can even be harvested from bio-mass, sewage or other waste.

In B.C., we are lucky enough to have clean hydro electrical power generation. On a worldwide basis, however, about 30 per cent of all greenhouse gas (Co2) emissions come from electrical power generation stations and that's mainly from the use of coal as a fuel.

Ah, I hear you say, but what about power taken from the electrical grid to extract the hydrogen from water? In a perfectly clean future world, that electrical power could come from the sun, via solar panels, or it could, of course, also be wind or some other green source.

Honda has constructed a hydrogen fuelling station at its R&D facility in Torrance, Calif., that I was invited to see, but I could not take pictures. The station uses electrical energy from solar panels to extract hydrogen from water.

Think about it -this fuel is produced right at the fuelling station - from water! No more leaky oil wells in the ocean, no pipeline across the country, no delivery trucks or tanker ships and no oil refining facilities.

Honda is also working on a hush-hush new (electrolyser) home edition refuelling station that may have even greater potential. It also takes water, and not necessary clean water, and extracts the hydrogen and vents the oxygen. It's a slow-fill system that doesn't need a compressor or tank to store compressed gas.

Add some solar panels on the roof of your home to supply the electrical power and the cycle is complete. You've got completely self-sufficient and sustainable transportation.

While battery/electric vehicles are in the spotlight right now and hydrogen fuel-cell vehicles are further down the road, many view them with even greater promise and importance as we move toward a low-carbon future and away from oil dependency.

The Specs

Motor output: Max. Speed: Range:

HondaFCXClarity

100 kW / 136 hp 160 km/hour 435 km

MercedesB-ClassF-Cell

100 kW/136 hp 169 km/hour 385 km