There’s just 18 months to go before Renault plans to start rolling out its battery-electric car range, and the firm is gearing up to spread the message to the masses. Today it announced plans for an extended test-drive programme designed to let potential buyers sample the feel of zero-emissions motoring: “For many motorists, driving an electric vehicle will be a new experience,” Renault’s press release burbles. “The absence of noise from the motor, the immediate availability of peak torque and the linear acceleration curve mean that drivers will need to develop new habits.”

We’ve driven a few electric vehicles and can’t help feeling that Renault’s real motivation has more to do with marketing hoopla than any real need to re-educate drivers. There’s actually markedly less to do in most EVs than in their fossil-fuelled equivalents. Most don’t have gears, for example. All use regenerative braking to replicate or supersede the engine braking we are all used to from conventional cars, meaning that you use the brake pedal in much the same way or less. The steering wheel is a pretty standard device, as are mirrors, tyres, seats and belts. So unless Renault has done something bizarre we don’t know about, the test-drive programme must surely be more about re-aligning expectations than driving habits. It wants us (and its rivals) to know that its cars are nearly here, and it’s confident in its product plans.

Those plans include three cars in 2011. The first two will be current vehicles that will have undergone a heart and lung transplant, ditching the fuel tank and engine in favour of lithium-ion battery pack and electric motor. One will be the previously announced Kangoo Express ZE, due in the middle of 2011, the other will be a family estate car. These will be followed later in the year by a bespoke electric urban car, and in 2012 by a compact hatchback EV.

Oddly, although Renault has announced the test-drive programme, it hasn’t said how to go about booking a stint behind the wheel. We’ll see if we can find out more...

It feels all wrong, for a green car enthusiast, to be climbing into the garishly upholstered driving seat of a Chevrolet Equinox soft-roader. It’s a big, square, two-tonne blue box with reverse-Tardis packaging. The viewpoint is commanding, the steering wheel is on the wrong side, and the air-con is blasting away to tame the summer heat. Worse, the 4x4 proportions are just for show - this is a front-wheel drive car. All in all, it’s not a very promising prospect for keeping our CO2 output under control.

But this beast has got it where it counts, and we aren’t outputting any CO2 at all today. This is not just any Chevy - it’s a HydroGen4 fuel cell research vehicle. Somewhere behind us are three bulky carbon-fibre fuel tanks pressurised to a fearsome 700 bar, full of a surprisingly small mass of hydrogen gas. Just 4.2 kilos of the stuff is good for 200 miles, apparently. Under the bonnet is a 73kW electric motor, powered by a fuel-cell stack that splices the hydrogen from the tank with oxygen from the air to produce nothing at all but electricity and water.

Alongside us rides a minder from GM Europe, who seems surprisingly relaxed given that we are about to pilot this expensive prototype on the demanding Hill Route at Millbrook Proving Ground.

We take Loop 1 and 2 on the course, which takes in slopes steeper than 1 in 10 both uphill and down, plus some sweeping corners replicating a typical British B-road.

We weren’t sure what to expect from our first drive in a fuel-cell vehicle, and are almost apologetic to report that GM has succeeded in making the HydroGen4 highly unremarkable to drive. The only electrifying experience on offer would involve grabbing a handful of cables under the bonnet.

The car starts on a normal turn of a conventional key - silently, of course, except for a sudden rush of chilled air from the dashboard vents. We slot an ordinary auto-box selector from P into D, release the ho-hum handbrake, and we’re off.

Throttle response is instant, the urge on offer reasonable. It’s no sports car, but it’s no slug either. The regenerative brakes offer no feel whatsoever, but numbness probably comes as standard in an Equinox. The helm responds to inputs in the expected manner, with pots of power assistance and little precision.

Progress is smooth and very quiet, with the deliberately poor surface making no impact through the big tyres and soft suspension. If the gearbox changes ratios we don’t notice - they’re not often needed in a car powered by electric motor. The box offers no special ratio for steep descents, as you will find in a Prius or Civic Hybrid, which can both increase their rate of regenerative retardation to capture extra energy and to spare the brakes on a downhill stretch. As we crest a rise and are faced with a road that drops away like a tarmac-covered ski-slope, we ask our minder what the best technique is for keeping downhill speed in check. “Use the brakes,” he says, with a shrug.

Uphill is similarly straightforward. The motor, less beefy than the one that will find its way into the upcoming Opel Ampera, provides acceleration even when hauling the HydroGen4 up a 10% slope.

There’s plenty to argue about when it comes to hydrogen as a road fuel. It’s energy intensive to produce, requires more energy to pressurise, and in worst-case scenarios can account for more released CO2 per kilometre than petrol. On the other hand, if it can be produced from renewable energy, it offers the genuine prospect of zero-emissions motoring without the need for lots of lithium. It’s generating the renewable energy that is the hard part, of course. Plus there is the not inconsiderable hurdle of establishing a hydrogen refuelling infrastructure.

There is also plenty to argue about when it comes to fuel cells, particularly the staggering expense of making them at present. GM doesn’t say how much it costs to create the HydroGen4’s stack, but it’s likely to loiter in the region of $200,000.

So while we remain sceptical of hydrogen’s future as a fuel, there is not much to argue about from behind the wheel. It’s amply clear that hydrogen can be made to propel a car with no drama at all.

This time next week, on 16 June, Hugo Spowers will have unveiled the prototype of his vision for urban mobility. We don’t know exactly what it will be like, but it will be very small, very light, four-wheeled, two-seated and powered by hydrogen.

Spowers was the driving force behind the Morgan Lifecar project, which produced a lovely looking one-off vehicle and a lot of test data but nothing that punters could actually hope to sit in and steer. The new project, Riversimple, aims to produce an actual product.

Not that you’ll be able to buy a Riversimple Hyrban (or whatever the car is called after its launch). But you might be able to lease one. And Spowers has plans to ensure you’ll have somewhere to fill up with the lightest element in the universe for fuel.

What else do we know? The monocoque chassis will be carbon composite; the driving force will come from four in-wheel motors, doubling as regenerative brakes; it has a top speed of 50mph and a range beyond 200 miles. We also know that the fuel cell will have a very modest 6kW output, backed up by 20kg of ultracapacitors to store regenerative energy and to provide four-fifths of the power available for acceleration.

Spowers thinks this combination of energy storage options will conquer the usual problem with fuel-cell cars: not the scarcity of filling stations but simple cost. The fuel cell hardware currently loiters in the region of $2,000 per kilowatt output, and that price needs to fall by a factor of 40 to around $50/kW to be price competitive with internal combustion engines, according to our knowledgeable sources. Which is one reason why you won’t be buying a Hyrban.

We await the launch with interest...