Saturday, 28 June 2008

How far will Renault's hydrogen fuel cell Scenic go?


The development costs mean that each of Renault's new hydrogen fuel Scenic ZEV H2 is currently worth about a million euros. But is the world really on the road to a hydrogen future?

By Sean O'Grady
Friday, 27 June 2008

The Renault Scenic ZEV H2 in action

The Renault engineer bent his head conspiratorially to me and vouchsafed his company's greatest technical challenge. Well, here’s a story, I thought. What could this be? A dud new engine? Dodgy electrics? A faulty batch of steel that will reduce all Renaults to a pile of rust inside a British winter? (Actually a few years ago that really was their biggest challenge. But I digress). No. The big problem for Renault, as for every other car maker, is really no secret at all - “it's the public”.

Well, he had a point. The public don’t like change. Which is perhaps why the most revolutionary car Renault has produced in decades, and probably ever, looks very much like a competent but ordinary mid-range people carrier.

Yet the Renault Scenic they invited me to drive round a track in rural France was a very special Scenic indeed: for the Renault Scenic ZEV H2 is powered by a hydrogen fuel cell.

The development costs mean its worth about 1 million euros. An expensive Renault, then. It won’t be going on sale anytime soon, however, even at that price. The Renault folk say it will be a decade before they’ve managed to get everything right. Weight and cost are the most pressing problems with this replacement for the familiar internal combustion engine, that and the fact that there’s nowhere to fill one up with gas.

Yet the Scenic is by no means the first hydrogen fuel cell car to be produced. Honda has beaten everyone to the front of the pack with its FCX Clarity model, now being leased in admittedly tiny numbers in California, but qualifying for the title of “production car”. Some 200 of these novel looking executive saloons will be out there very soon.

It follows a similar pioneering experiment by Honda a few years ago, also in California, with a small hatchback driven by hydrogen gas. Mercedes-Benz and Opel, among others, have also launched experimental hydrogen fuel cell models. I’ve even driven the Mercedes, a converted A-Class, around London. It was a few years ago, when the PR drank the water that came from the exhaust, H2O being the only product of the process. A memorable moment. So it has been done before, Renault.

Yet the Renault is interesting both because it is a very convincing conversion of existing technology and because it shows how even those manufacturers which have disdained alternative technologies in the past are now embracing them.

Carlos Ghosn, Renault’s famous and charismatic leader, is also putting a huge effort into conventional electric cars for his firm and partner Nissan, with some ground-breaking schemes in Israel and Denmark on the way, chosen for their compactness and mostly flat topography: electric cars like short journeys without inclines.

The hydrogen fuel cell car is also electric, but it has more oomph and more range than the usual milk float. You pump some hydrogen into the car much as you’d refill your car with petrol or diesel, and the gas chemically reacts with oxygen from the air. That takes place in the “fuel cell” or stack, and the electricity generated amounts to 90kw - enough to tug a medium sized car around.

The power is stored in lithium batteries, of the kind you have in your laptop, which is both good and bad for PR, given the incidents of spontaneous combustion that were reported a while back. There is also a conventional 25kw back-up battery on board. That lot powers an electric motor and that moves you and your Scenic along at up to about 100mph. It has a range of perhaps 150 miles. Both are far in advance of anything the conventional electric car scene can provide. Your hydrogen fuel cell Scenic sometimes leaves a little trail of water from the exhaust, like an incontinent spaniel. Very clean.

So as Honda, Mercedes-Benz, Opel, and now Renault have shown, the technology is out there, and it works well. The car felt fine to me; very quiet, obviously, with the traditional engine removed. It is noticeably heavier in the handling, as the Scenic ZEV has gained some 300kg of weight in the conversion, an issue for the engineers. Yet it stopped OK, accelerated briskly and went round corners at moderate speeds in a predictable fashion. As far as the safety of the tank is concerned, this pressurised unit has apparently had grenades thrown at it and survived, so it is probably more secure than most petrol tanks of today. But such concerns as this, and vague memories of the Hindenburg disaster will, I fear, prevent the public from taking to hydrogen fuel cells without a great deal of persuasion.

Trickier though is the whole question of whether this great leap forward is actually worthwhile, on environmental or economic grounds. The technology is there; but that doesn’t mean we have to use it. For a start there’s the cost. Economies of scale would soon kick in, but it may well be that there is still a cost penalty compared with the old-fashioned petrol or diesel car. Will we want to pay that?

Then there’s the small matter of scrapping our entire internal combustion engine and fossil fuel infrastructure. We would have to build, or adapt, an entirely new distribution structure. That will be obviously pretty expensive.

Finally, we need to factor in the real cost to the environment. If the hydrogen is made via electrolysis that too will need energy to produce it and energy will be needed to shift the hydrogen around the country to filling stations. Or we might have mini processing plants throughout the land. Who knows? Are these methods of moving and making hydrogen efficient? Are they run off fossil fuels or nuclear or renewables? It makes a huge difference.

And, as some point out, what is the purpose of converting energy into hydrogen to be transported everywhere and to make electricity on board a car when the simplest thing might be to use the existing national electricity grid and simply plug our electric cars into the mains? A hydrogen future is perfectly feasible, but I’m not entirely sure we’ll want it.

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