You get into the Edge, turn the ignition key and wait for the fuel cell to burst into life. Under the floor is a reservoir of high-pressure hydrogen — the same stuff that powers the sun. It’s like being at the helm of a starship. Unfortunately, before you can say “Take us out of orbit, Mr Sulu,” you’re met by . . . silence.

Welcome to the future. It’s mute. Gone is the roar of the V8, the screech of tyres, the howl of the transmission. All you’ll hear in the cabin of this hydrogen-powered prototype is an electric fan cooling the hidden apparatus that turns hydrogen into electricity and powers four wheel-mounted electric motors (yes, it’s a 4x4).

The vibration from thousands of muffled explosions inside a cylinder block, the plume of noxious exhaust gases . . . these are things of the past. The only emission the Edge produces is water so pure you can sip it from the tailpipes. If you became depressed about the demise of the internal combustion engine and the fantastic machines it spawned, it would be no good trying to end it all by shutting yourself in the garage and running this car’s power unit. You’d die of boredom before you’d suffocate.

This is what car makers have been telling us about hydrogen power for years, so what is different about the Edge? Well, if you believe the Ford sales speak, this car represents a huge technological leap forward in the development of the hydrogen fuel cell as a viable alternative to the combustion engine. That’s because the Edge is the first alternative-fuel car to have a travelling range approaching that of a conventional car.

Existing prototypes can typically travel only about 100 miles between refills, but Ford’s engineers have improved the efficiency of the Edge’s fuel cell (the device that turns hydrogen into electricity to power the car’s motors). They’ve also added laptop-style lithium-ion batteries so the car can be recharged overnight, if desired, thereby extending its range to 225 miles. This, says Ford, makes it a truly viable green machine.

But what is it like to drive? All the pulling power from the Edge’s electric motors is available immediately. Unlike a conventional engine, they don’t need revving. That should provide rubber- burning acceleration, but it doesn’t because the combined 250bhp is only gradually released to prevent wheelspin. Press the accelerator and the Edge glides gently up to a top speed of 88mph.

It’s a car designed in a laboratory instead of a workshop. I test-drove it — with deep suspicion — at Ford’s chrome and glass research centre in Germany. Usually the trouble with eco-friendly cars is that they are neither green nor friendly. They run on alternative fuel that has been derived from fossil fuels, they cost the earth without actually saving it and they’re no fun to drive.

In that sense, the Edge is no exception. If it went on sale today it would cost at least ¤1m — about £812,000. It uses hydrogen that has been made using natural gas or power-station electricity, so ultimately it’s no cleaner than a conventional vehicle. And because of its weight — at 2.5 tonnes it’s only slightly lighter than a Rolls-Royce Phantom — it handles as though it’s full of water — which, in a molecular sense, it is.

It uses complex technology and exotic materials that will never be cheap, though mass production will eventually bring the cost down. Worse, there’s nothing even faintly edgy about its performance — it’s the most misleadingly named car since the Skoda Rapide.

So what is the point of the Edge, apart from being a public relations tool to help make Ford look caring? Ford’s argument is that in 10 years’ time there will be a network of plants producing hydrogen from cheap, nuclear electricity. Then we’ll all be able to run cars such as the Edge without generating any carbon monoxide or CO2. Our carbon footprints will shrink to the size of inline skates.

Why not just use cheap electricity to charge up battery-powered cars? The answer is simple: you can’t just stop and fill them up like you can when your car runs on conventional fuel or gas.

So it’s worth taking notice of this prototype, because the Edge is what you’ll one day be driving, even if it takes more than 10 years to get here. Yes, it’s unrefined, a bit like the first mobile phones. And the car of the future won’t look exactly like this one. Ford simply built its hydrogen technology into the body of an existing model, a family SUV that sells in the States for £15,000. What really matters is under the skin.

Ford says it can improve performance still further, thanks to technological spin-offs from a hydrogen racing car — the Ford Fusion Hydrogen 999 — which last year claimed the world land-speed record (207.3mph official, or 210mph unofficial) for a production-based fuel-cell-powered car.

The company is in the process of increasing the amount of hydrogen carried, by boosting the storage pressure, and that will give the Edge a range of more than 300 miles. And, if you believe Germany’s TUV (Technischer Uberwachungsverein — the official vehicle-testing agency), hydrogen is a safer vehicle fuel than petrol because it rapidly dissipates if it leaks in an accident.

That’s all very well, but can you find hydrogen filling stations at 300-mile intervals? No. There are only a handful on the Continent and none in Britain. You will only find stations that close together along California’s hydrogen highway, where Arnold Schwarzenegger, the state governor, has forced fuel companies and car makers to co-operate on hydrogen.

Will anything similar happen beyond the eco-obsessed US west coast? Is Schwarzenegger likely to take over the world and build a global hydrogen highway along which we’ll all glide in silent machines from the future? Not unless the plot of Terminator 4 comes true. So we can hang on to our V8s for another decade — at least.

Ford Edge

POWER UNIT Ballard Halo fuel cell stack, dual e-Drive electric motors

POWER 250bhp

TORQUE 340 lb ft

FUEL 4.5kg hydrogen @ 350 bar

RANGE 225 miles (300 miles with 700bar storage)

TOP SPEED 88mph

PRICE €1m – about £812,000

AVAILABLE 2015 for fleet use