It’s a few years now since the first serious prototype fuel cell cars hummed onto the radar, yet they’re still very much at the research stage. That said, they have come a long way considering the rocket science involved in making them work and the huge technical mountains engineers are having to climb. The Edge is the latest from the Ford stable and is based on the production SUV crossover. Replacing the usual 3.5-litre V6 Duratec engine is the ‘HySeries’ drive comprising a fuel cell, battery and two 130kW electric motors driving four wheels.
So what’s special about the Ford Edge HySeries?
The Edge with HySeries Drive is the world’s first fuel cell plug-in hybrid. A plug-in hybrid is one where the battery powers the electric drive and the engine is used only as a generator to recharge the battery as it becomes depleted. Having plugged the car into the mains at night, you leave home in the morning on a full charge, use of the engine being kept to a minimum. In the Edge, a hydrogen fuel cell replaces the engine and starts re-charging the battery when the charge level drops to around 40 percent.
How does it drive?
Inside, the Edge looks like any other big American SUV except the two big dials read speed and current draw rather than speed and revs. Twist the key to start and the system ‘fires up’ to a modest hum. Then select drive as you would in a normal auto and the electric motors begin turning as the car moves off, like an electric train.
Cruising out into the traffic near Ford’s Research Centre in Aachen, the Edge is still virtually silent except for a quiet whine from the drive motors. Inevitably, it sounds a little like a giant dodgem car only a lot more refined.
260kW roughly equates to 348bhp and foot down, the acceleration feels impressive considering the car’s bulk. We quickly reach 75mph on a straight stretch of the rural test route which bears out Ford's claim of an 86mph top speed. Only the narrow roads stand in the way of taking a bigger stick to the Edge which feels as willing as it might with the Duratec under the hood. The battery takes a bit of a beating though, and the fuel cell has to work overtime to keep up.
The Edge has regenerative braking, so the motors act as generators when slowing, adding charge to the battery. It has a couple of settings to increase or reduce the braking effect and shotgun-riding fuel cell engineer Sabine Flanz soon decided it was time to switch to ‘max.’ That said, the monster hybrid survived an afternoon at the hands of a couple of journos and a film crew without running out of steam. Refuelling happened at a hydrogen pump in pretty well exactly the same way as you would refill an LPG car at a UK service station.
Click 'Next' below to read more of our Ford Edge HySeries first drive
What makes the Edge different?
In most fuel cell cars, the fuel cell powers an electric drive motor directly, without a battery in between. It’s taken years and shed loads of money to get fuel cells to do this because actually, they’re better suited to churning out a steady stream of electricity much like a conventional battery charger. Driving an electric motor directly means they have to respond to the driver getting on and off the accelerator much like a conventional engine would. In contrast, plug-in hybrids revert to the old idea of using the fuel cell to charge the battery of what’s effectively an electric car.
So why the about-turn?
Partly because lithium-ion batteries (think laptops and mobile phones) have improved so much and partly because the fuel cell system is simpler and cheaper. The ‘Halo’ fuel cell in the Edge puts out just 40kW and doesn’t need many of the more expensive components used in the direct drive type. Other reasons include the fact that energy producers are keen to sell electricity to the transport sector and average journey times for most drivers are quite short, which fits well with the idea of overnight charging.
What’s the range like?
The Edge carries 4.5kg of compressed hydrogen in a carbonfibre tank at a pressure of 350bar, extending the range by another 198 miles to make a total of 223 miles. Using a fiendish calculation, Ford reckons the equivalent petrol fuel consumption would be around 49mpg, an impressive figure considering the Edge weighs in at around 2.5 tonnes.
Translate this technology into a European platform, such as the Focus used for Ford’s main fuel cell programme, and you’d have a tool more suited to European roads. But the Edge does prove that fuel cell electric systems can work in big heavy cars as well as lightweights.
Plug-in versus direct fuel cell? Nobody seems to know at this stage – hence all the research. And we’re still in for a very long wait before hydrogen filling stations are even remotely commonplace. But should you remain unconvinced about the potential performance of electric drive, look no further than Ford’s Fusion 999, which took the land speed record for a fuel cell car a year ago at 207mph.