Honda FCX Clarity Hydrogen Drive Technology

Virtually every automaker is tinkering with hydrogen technology, and for good reason. Whether you burn the lightweight gas in an internal combustion engine or feed it into a fuel cell stack, what you get on the "dirty side" is effectively no more than water vapor. In a world worrying about smog and global warming, hydrogen is seen, by many, as the ultimate clean fuel.

First seen at the 2005 Tokyo Motor Show, Honda plans to begin leasing the FCX for $600 a month, and not just to carefully selected corporate fleets, but to everyday consumers. "The FCX Clarity is a shining symbol of the progress we've made with fuel cell vehicles and of our belief in the promise of this technology," proclaims American Honda president and CEO Tetsuo Iwamura. "Step by step, with continuous effort, commitment and focus, we are working to overcome obstacles to the mass-market potential of zero-emissions hydrogen fuel-cell automobiles." 

Honda has actually applied the FCX badge to several vehicles. Honda has learned a valuable lesson from its Japanese rival, Toyota , whose Prius is a distinctive visual standout. The FCX is a futuristic machine, first impressions suggesting a cross between the new Honda Accord and the Prius. Toss in a dash of the Honda CR-Z concept vehicle that debuted in Tokyo, last month - at least the show car's split rear glass, which folds over into the tailgate. If we had any complaint, surprisingly, it was rear visibility, despite the sedan's expanse of glass.

The sedan's instrument panel vaguely resembles that of the new Accord, with its stairstep layout. There's a huge, high-res LCD for the built-in navigation system, or to display the complex power system at work underneath. Our test car had a surprising number of little fit-and-finish problems, but we're willing to give Honda a pass, considering this is a prototype of an extremely low-volume, largely hand-built car. Nonetheless, we're hoping for typically Honda-level refinement when the first cars actually reach customers.

The FCX is extremely well-equipped, overall, with niceties such as dual-zone digital climate control, adaptive (radar) cruise control, voice-activated navigation, and a sweet AM/FM/CD/XM audio system with a jack for your iPod or MP3 player.

Oddly, while the doors and windows are power-operated, the seats are manual. In terms of safety, the FCX Clarity is equally well-equipped, with six airbags, anti-lock brakes, stability and traction control, active headrests, and a radar-guided collision mitigation system.

Though it's extremely aerodynamic, the FCX uses a conventional steel body, with a steel chassis and aluminum subframe, rather than the costly, ultralight materials that could have been used. The FCX delivers an estimated range of 270 miles on a tank full of hydrogen. (The EPA considers a kilogram of hydrogen to equal a gallon of gas.)

A fuel cell "stack" consists of a series of permeable membranes coated with noble metals, including platinum, rhodium and palladium. The hydrogen passes through the membrane, in the process shedding an electron, the basic stuff of the electricity that runs a fuel-cell vehicle's electric motor. When the hydrogen combines with air, it forms water, which you can spot coming out of the FCX tailpipe as either steam or a spray of liquid.

The latest-generation Honda stack, along with the rest of the fuel-cell system, is about 400 pounds lighter than in the earlier FCX, the stack itself now about a fifth the size of early stacks. The overall drive system, company officials note, is roughly the same size as a comparable gasoline-electric drivetrain. Honda notably chose to go with a "low-pressure" fuel tank, storing those 4 kg of hydrogen at 350 bar, or 5000 psi. Firing up the Clarity is simple: just press the start button. Step on the throttle and you're likely to be surprised by the Clarity's aggressive launch. The system produces 100 kilowatts of power, with a modest additional assist from the onboard batteries, which operate much like those in today's gas-electric hybrids. That works out to a seemingly modest 134 horsepower, but the numbers underrate the actual kick of an electric drive system, where you get maximum torque the moment the motor starts to turn.

The agility of the sedan is impressive. On steep inclines, the fuel-cell vehicle can go up them without any hesitations, performing about as well as the new Accord. The Clarity has double-wishbone suspension - and Honda engineers who were able to package the hefty fuel cell components as low as possible. One of the most striking features of any fuel-cell vehicle is the distinct lack of traditional powertrain noises. Instead, you suddenly discover all sorts of sounds normally muffled beneath, like controls and pumps - especially the compressor driving air into the fuel-cell stack.

The somewhat high-pitched noise, along with the sound of the drive's electric motor, takes some time getting used to, though in the FCX, it's a significant amount quieter than the screeching of earlier fuel-cell vehicles.

How many customers Honda hopes to attract when it starts leasing the FCX next year is unclear at this point. The company is "waiting to gauge the market's reaction," insists U.S. marketing chief Will Walton. All well and good, but what about the hydrogen? Under pressure from the state, the auto industry has been flooding the California market with hydrogen prototypes, and that's encouraging the development of a real service-station infrastructure. Honda officials expect as many as 30 hydrogen pumps to be available next year. The fuel should cost about $5 a kilogram, meanwhile, so on a per-mile basis, the FCX will actually prove more affordable than comparably-sized sedans (except, perhaps, the Prius). While the first Clarity sedans will be leased in the L.A. area, Honda officials would like to extend the experiment to other parts of the country.

Quick Facts

Base price: Three-year lease, $600/month
Engine: Fuel cell and 288-volt lithium battery, 134 hp/189 lb-ft
Transmission: Direct-drive electric motor, front-wheel drive
Curb weight: 3582 lb
Fuel economy (EPA city/hwy): 68 mpg combined EPA cycle (est.)
Major standard features: Power windows/locks/mirrors; AM/FM/CD/XM/MP3 audio system with iPod input and steering wheel-mounted audio controls; dual-zone climate control; remote keyless entry; tilt/telescope steering wheel; alloy wheels; voice-operated navigation; active (radar-guided) cruise control
Safety features: Anti-lock brakes, traction and stability control; dual front, side and curtain airbags; tire pressure monitors Warranty: All maintenance provided during three-year lease

Toyota's Hydrogen Drive Technology

As seen in the chart, currently a gas vehicle (GV) and gas hybrid vehicle (G-HV) are the most efficient. This is because both use gas and the well to tank percentage right now is 88 percent efficiency. This means that only 12 percent efficiency is lost in production of fuel. Once you get the gas in the tank, the tank to wheel efficiency goes way down in an internal combustion engine and up in a hybrid. Hydrogen fuel cell vehicles (FCHV) are woefully bad from well to tank (production), at only 58 percent efficiency. According to experts, "A hydrogen powered fuel cell vehicle emits only water. Carbon monoxide, however, is produced when hydrogen is made from fossil fuels, as we currently do. If we intend to reduce carbon monoxide, we must go beyond tank to wheel efficiency and tackle well to tank efficiency as well. The hope of all concerned is that the production of hydrogen can become more efficienct, with less emissions.

In the mean time auto manufacturers are working on vehicles that can run on hydrogen. I drove the Toyota FCHV and was amazed and excited.

The world breaks out hybrid technology from hydrogen fuel cell technology. Toyota does not. The Toyota Prius was the world's first mass produced hybrid car. It combines an internal combustion engine (ICE) and a battery, power control unit and motor to achieve energy management, fuel efficiency and less emissions.

Toyota has applied the same practice to their Toyota Fuel Cell hydrogen vehicle (FCHV). The one big difference is they have replaced the ICE with a fuel cell stack.

In the FCHV, the electricity comes from the fuel cell, powered by an electric motor. The fuel cell gets its energy from hydrogen whereas the ICE gets its energy from gasoline.

The fuel cell cars of today should be kept and put in the Smithsonian, just as the Model A and Model T surely reside in museums. The current hydrogen cars are the cars of a hundred years ago. The technology on these cars will be obsolete before they are finished producing the first commercially viable hydrogen car.

 If I were to compare a large ICE SUV with the Highlander hydrogen (HH) there would be some surprising results. While one can feel the weight difference and the difference in suspension the HH is much quieter. Remember, you're using the same fuel NASA sends space rockets into orbit. There is no meting the engine to the transmission for optimal torque, the torque on hydrogen comes in at 0 rpm. The next issue is the drive mileage between fuel ups.