We here at DailyTech have profiled fuel cell vehicle on numerous occasions. Companies like General Motors, Ford and Honda have showcased both concept and production hydrogen fuel cell vehicles over the year and they have always generated much interest from our readers.

DailyTech was recently given a chance to take a fuel cell vehicle out onto the streets of Las Vegas during the 2008 Consumer Electronics Show (CES).

The vehicle tested, the fuel cell version of the Chevy Equinox, was modified to include an electric motor, fuel cells, hydrogen storage, batteries, and more.  The key component is GM's fourth generation fuel cell stack which is about the size of an inline-6 engine turned sideways.  A single 97 HP, 236 lb-ft co-axial electric motor drives the front wheels.  The car has a pack of nickel-metal hydride batteries, which provide 35 kWh of on demand power for peak loading during acceleration.  The car features three 10,000 psi storage tanks which can hold up to nine pounds of hydrogen.  Two tanks are found beneath the rear seat, and one is mounted near the rear suspension.  The car has enough fuel for a 200 mile trip as verified during EPA testing.

The car looks similar to its non-fuel cell brethren save for a new front grill, bumper, revised interior trim, four exhaust outlets and a snazzy silver-green paint job.  The car also is slightly heavier, adding an additional 500 pounds to the standard curb weight of 3860 lbs.  It does 0 to 60 mph in about 12 seconds – quite slow by modern standards for a crossover. 

It also includes protection against water vapor freezing in the stack and can start up at sub-freezing temperatures -- a first for limited production fuel cell vehicle.  Life expectancy of the fuel cell stack is still low at 50,000 miles, due to stack corrosion, but this is expected to be greatly improved in the next revision.  The car is extremely safe, both with standard safety features, and passing crash testing with a running hydrogen system.  These tests were conducted under careful government supervision and the Equinox Fuel Cell passed them with flying colors.

A limited fleet of 100 vehicles is being deployed to California, New York, and Washington to select participants, but until then only a select few lucky individuals, including DailyTech's Brandon Hill and Jason Mick have been able to experience the Equinox.

Brandon:

To begin our road test of the Equinox, Jason Mick and I had to show proof that we had valid drivers licenses and sign two wavers: one for GM and one for CEA. After taking a brief walk around the vehicle, I was given the keys to the vehicle and asked to hop into the driver seat.

I was given an overview of the gauges which are slightly different from a normal internal combustion engine (ICE) Equinox. In place of the tachometer was a gauge to give the status of the fuel cell stack. Otherwise, things looked quite normal to me. I buckled up, turned the key to start the vehicle and there was just silence -- no starter sounds, no engine running; just an eerie silence.

I adjusted my mirrors, released the hand brake, put the vehicle in drive and took off into absolutely crazy Las Vegas traffic. As I was driving, I could hear no sound from the electric motors or fuel cell stack -- all I could hear was a slight wind noise around the A-pillars and thumping from the suspension as the wheels traveled over bumps/potholes in the road.

Throttle response was instantaneous as there is no transmission to speak of (the electric motor is direct drive) and 236 lb-ft of torque available at any time. It was truly no different than driving another vehicle and I felt right at home. The only detraction from the driving experience was a somewhat spongy brake feel. I was assured by the GM engineer that this was simply a programming issue and this particular vehicle had not yet received the latest software update which resolved the problem.

Jason:

After Brandon's drive I was eager to get behind the wheel of the Equinox myself.  The ignition is very different from starting gas engines.  Instead of a pushed turn, followed by a release as with most cars, you just clicked and instantly the car was on, starting up.  On my drive, our guide pointed out that when the car started up a LCD panel on the center of the dashboard console illuminated displaying an animation of how the engine was running, the basic flow of water, H2 gas, air, and electricity through the system.

Driving the car on the city streets, the biggest difference was the responsive acceleration, which was very linear, as opposed to a gas engine vehicle.  The result was made starkly apparent when the light turned green I would whoosh steaming past the lead-footed taxi drivers and sports car riders, who looked utterly shocked that they just got passed by an SUV.  I'm no race car driver -- the acceleration, was simply that much better, making a car like this great for the fast start, fast stop, nature of city driving.

On an empty stretch of street I did manage to take the car up to about 55 to 56 mph, where the acceleration harshly leveled off.  The reported top speed was 100 mph, but I believe GM speed limited the vehicles to 60 mph, to prevent the riders from getting carried away.  Thus, this is not necessarily indicative of the vehicle's speed limitations, but I can happily report it was quite responsive in reaching highway speeds.

An additional observation was that the steering seemed extremely smooth and responsive.  The vehicle turned very smoothly.

We both rode in the Chevrolet Tahoe DARPA Challenge vehicle.  The SUV was the victor in the DARPA 2007 Urban Challenge, which tasked the fully-autonomous vehicle with navigating through city streets, obeying all traffic laws and interacting with human-driven traffic.  

The vehicle was a modified Tahoe with a number of GPS, video, laser, radar, and LIDAR sensors and inputs so that it can see the road and know its location.  The key among these sensors is the velodyne, which contains 64 lasers in a wide array, spins at 10 Hz., and collects one million bits of data per second -- this provides a 3D view of close terrain.  While other teams had velodynes the key to GM's victory, according to its engineers, is how the collected data is processed.  The processing and decision making is accomplished by 10 Intel dual-core IBM blades running on a modified version of Ubuntu Linux called the Tartan Racing Operating Command System (TROCS).  The vehicle's logic consists of over 350,000 lines of code.  The entire system was built in 14 months for the challenge, via a collaboration of Carnegie Mellon, GM, Caterpillar, and Continental.

GM spoke about the vehicle during its keynote address at CES 2008, and stated that it sees it as the next step in the evolution of such technologies as autonomous cruise control and blind spot management.

We got in the vehicle after an interesting presentation, and noticed that there was plenty of room to sit comfortably -- the electronics did not encroach on passenger space and were cleanly wired.  The vehicle had a number of appended mechanical devices that simulated the foot on the pedals, so that the default pedal system could be used.

Taking off, the vehicle deftly accelerated and braked, steering through a complex obstacle course that would give many human drivers problems.  It obeyed traffic laws, stopping at stop signs placed on intersection of the course and properly yielding right of way.  The ride was generally quite smooth, though the braking was a bit jumpy at times.  The engineers explained such issues would be ironed out with time, and that given the very short 14 month development period, incredible progress could be made in a relatively short span to fine tune the vehicle.

The car's greatest moment of glory came when it approached a stop sign and saw a human driver in a different vehicle coming up on the stop sign from the left.  As the human driver was fast approaching, the Tahoe accelerated from the stop sign, and then rapidly braked, despite having right of way.  The human driver braked just in time to avoid running the stop sign, but it was very reassuring to notice that the Tahoe "saw" him and would have avoided the accident, had the human driver ran the sign.  The engineers verified this is normal behavior -- the vehicle can deal with erratic behavior such as cars running stop signs, swerving into lanes, etc. caused by less logical human car operators.

The smooth ride, and the incident where the Tahoe almost saved us from a crash, showed that in terms of ride quality and safety, the system seemed at least as safe as a reasonably able human driver, if not safer.  Obviously tremendous work will have to be done to compact the system, reassure the public, and make the system capable of handling every city street in the country.  Still, it is impressive just how far the technology has come.  A fully autonomous car is not that far in the future, as our ride in the GM's DARPA winner showed us.

Both vehicles show the terrific things GM and the auto industry are accomplishing as they work hard to make cars, safer, easier to use, cleaner, and more efficient.  DailyTech thanks GM for this terrific opportunity to explore these innovations first-hand.