I’m laughing the sort of maniacal, involuntary laughter that comes from doing something a bit silly. The last time it happened I was hanging upside down from the seatbelts in an aerobatic plane at the top of a loop-the-loop. This time I’m in a car. Or, to be more specific, the Tesla Roadster. I’ve just pulled out into London’s traffic and hit the accelerator properly for the first time. The result – apart from my mirth – is quite extraordinary, as the Tesla’s response to inputs is instantaneous, as it lunges forward with alarming ferocity.

There’s no noise, no drama, just pure acceleration that’s as linear in its delivery as anything I’ve ever experienced before. Until now I’d dismissed Tesla’s sub-four second 0-100km/h time as utter bunkum – now I have absolutely no doubts. It’s so gloriously addictive, in fact, that I simply ignore the suggested route around London’s busy streets and head quickly out of town for another accelerative fix. A city car it definitely isn’t.

Few people notice the Tesla, as it’s not dissimilar to the Lotus Elise it borrows its chassis from. The body is quite different in reality – it’s more sombre-suited than the Lotus yet more exotic too, as it’s built of carbon fibre. Even so, it gets attention only from the best-informed bystanders. Only one fellow recognises it, his cigarette nearly falling from his lips as he stands slack jawed as I silently cruise by in my search for an arterial road out of London. His wild gesticulating doesn’t seem to concern his mate, though, who’s clearly more concerned about getting into the pub than witnessing what could rightly be considered a landmark car rolling by.

The Tesla is deadly in town; the way it delivers all its 380Nm of torque from zero rpm means that absolutely nothing, not even determined motorcycle couriers, can beat it away from the lights. It’s comically fast, in fact, forcing a big grin to my face. Inside the Roadster it’s all very familiar – the dash is borrowed from the Elise, and the seating position, instruments and the view out are all very similar to the Hethel-made machine. There’s an additional display mounted to the side of the steering column – not dissimilar to a portable sat nav screen – that shows the battery’s status.

Tesla figures on around 360 kilometres per charge, depending on how you drive it. I guess I'd struggle to manage that the way I’m using the accelerator. Even after an hour of stop-start traffic punctuated by brief forays up towards the rev counter’s 14,000rpm redline I’ve only used a couple of bars worth of battery power, and the range has stayed resolutely at 140 kilometres – more than enough for the average commute.

I’ve never been so happy to reach the M4, the usually horribly congested motorway leading out past London’s Heathrow airport, which today was mercifully free of traffic. What’s more, heading west there are no speed cameras so I have free rein to push the Tesla past the 50-60km/h that I’ve been limited to until now. Nothing I’ve driven, save perhaps for the most ludicrously over-endowed supercars, has been able to deliver so much so quickly – the Tesla accelerates with real conviction regardless of how fast you are going when you push the pedal to the floor.

Top speed is around 200km/h, but Tesla figures 170km/h for sustained high speed cruising is more realistic – the performance drops off as the motor heats up. It’s not about the top speed, though, but the way it goes about getting there. Really, it couldn’t be simpler; the 250hp electric motor is mated to a single-speed gearbox. There are two pedals: one for go, the other for stopping – but such is the regenerative effect of the motor as the Tesla scavenges back otherwise wasted energy that I barely need to use the brakes. Except when I get a bit carried away on the slip road and look down at the speedometer. This car is quick.

The lithium-ion battery pack is the real talking point with the Roadster, as Tesla has managed to pack a lot of punch into its power source. It’s so good that almost every mainstream manufacturer has come knocking at Tesla’s door wanting to get involved. Rumour is that Tesla will be announcing a co-operative agreement soon with a major manufacturer: which one is still open to speculation, though.

The history of the Tesla Roadster’s conception underlines why in a world of automotive dreamers this car has succeeded. Driven by Silicon Valley money men with the vision and contacts to make things happen, Tesla might have stumbled a bit getting the Roadster to market, but now it is here and gaining serious momentum. Its electric drivetrain will also underpin a saloon that’s due in 2009, and the modularity of that car’s all-new platform – unlike the Roadster it won’t be based on the Lotus Elise’s extruded aluminium chassis – could allow everything from SUVs to GT cars in time.

However, right here, right now all that matters is the Roadster. With production finally up and running Tesla is bringing its revolutionary sports car to Europe. A figure of €99,000 buys you one before taxes, and the launch ‘Signature Edition’ cars come with a leather-covered dashboard, special wheels and a bare carbon-fibre hardtop and afford the buyer the kudos of being an early adopter. You can have absolutely any colour in Dupont’s paint range, too. Even so, that’s a huge heap of money, but you’ll save a fortune on your fuel bills. The Tesla costs around 3 cents a kilometre to run. Even factoring in a replacement battery pack (after 5 years or 160,000 kilometres) that still only goes up to around 17 cents per kilometre.

Charging takes anything between 4 to 16 hours, depending on the rating of your outlet (a household plug needs the maximum duration for a full charge). To be properly green that electricity really should be sourced from a carbon-neutral source, and many American Tesla owners run their cars on energy sourced at home from wind and solar generators.

How it’s powered isn’t my concern today; how it drives is. Unsurprisingly, it’s very much like the Lotus it’s based on, though the additional weight from the battery does make itself felt in tighter corners. The steering is unassisted, making it rather heavy at parking speeds, but the compensation for that is incisive response and crisp feel when on the move. Although the ride is good, even on the cratered tarmac that makes up London’s streets, the Roadster lacks the ultimate precision of an Elise, but it runs it close enough to still provide an experience that’s largely unmatched among its rivals. What are its rivals, though? The Tesla more or less stands alone in providing green sports car motoring. Sure, there are a handful others, Venturi’s Fetish among them, but Tesla is the only one that seems to have real substance to its claims.

Real substance and quite staggering capability: The Tesla is an eureka moment in the history of the car, a landmark that has been achieved by the can-do attitude, financial backing and expertise of a bunch of Californian high-flyers. It can only get better too – as battery technology improves so will charging times, performance and range. That it is a good electric car isn’t the issue here; that it is a good sports car is. Indeed, the Roadster is genuinely able to hold its own among all its sports car rivals. That a small Californian firm has so comprehensively trumped the mainstream car manufacturers into production with a genuinely viable and highly credible alternative to an internal-combustion-engine car should be a source of embarrassment for the entire industry. If the Tesla is the future of motoring, bring it on...

Tesla Roadster Signature Edition
Engine: Mid-mounted electric motor
Output: 250hp, 380Nm
Transmission: Single-speed auto
Acceleration: 0-100km/h 3.9 seconds
Top speed: 200km/h
Economy: 0.9 litres/100km (equivalent)
CO2 emissions: 0g/km (depending on source)
CO2 Tax Band: N/A
Weight: 1,200kg
Boot capacity: N/A
Base Price: €99,000 (plus taxes)
For: It’s the future of motoring, pace, feel-good factor
Against: Compromised sports car layout, very pricey
Rating: 9/10