We can see why he is sceptical. High performance batteries are the key to the viability of electric cars and the supply of reliable and cost-effective lithium-ion batteries will dictate the roll-out schedule for E-Flex as well as the mass-produced electric cars from other manufacturers, notably Renault-Nissan.

Lithium-ion batteries come in several different forms. GM is depending on its suppliers – either LG of Korea or a US subsidiary of Continental – to produce purpose-built battery packs using special flat cells. Tesla has beaten it to the market by using proprietary cells like those of laptop computers and power tools. These cells, called 18650, are cylindrical, 65mm long, and readily available from a number of suppliers. The Tesla needs 6,831 of them, wired together in blocks and gathered together in a liquid-cooled box.

Apart from the complexity, underscored by the overheating problems that have been encountered with laptops, Telsa’s is an expensive solution to the problem of providing enough power for a high performance electric car. Perhaps that doesn’t matter because the Tesla is also sensationally dear: $122,000 in America and £92,000 in the UK.

So only wealthy environmentally-committed enthusiasts will put their names down to buy a Tesla Roadster. More than 1,100 orders have been received in the US alone; by last month the first 16 had been delivered. For Europe, a launch edition of 250 cars will be available from next May. Sales in other parts of the world will follow.

If the Roadster looks familiar it is because it is. Tesla short-cut the blacksmith aspect of car making by adapting the Lotus Elise two-seater convertible. Lotus builds the aluminium chassis and fits the specially-designed composite body panels alongside the Elise in its plant in Norfolk, England. These ‘gliders’ are sent to California to be fitted with the 250 bhp electric motor, battery pack and electronic control system.

What emerges is a car with most of the character and agility of an Elise – even if it is 350kg heavier - and similarly Spartan accommodation. The surprising things are that it so quiet – there is none of the usual electric vehicle whine – and so quick.

With no more than a hard push on the accelerator, it will go from 0-100 km/h in 4.5 seconds and reach over 200 km/h. There is no gearchanging involved; the Tesla manages fine with just one ratio.

The regeneration system which feeds energy back to the battery pack when the car is braking or coasting provides the equivalent of engine braking when you come off the accelerator. The effect is so strong that, driving at moderate speeds in town traffic, you hardly need to use the brake pedal.

Tesla claims a range of up to 360 km, way further than any other electric car to date. The battery pack will take 16 hours to charge from a normal household mains but only three hours when plugged into an industrial 63-amp system.

Despite Bob Lutz’s comments, Tesla is convinced that its battery pack is reliable and durable. The battery cells are rated for 500 recharging cycles, equivalent to 150,000 km, and Tesla guarantees the whole vehicle for three years. If the battery pack has to be replaced after this time, a new one will cost a cool $22,000.

The next step for Tesla is to produce a second model, a four-door coupe designed from scratch but with a similar power system to the Roadster. Larger production, and year-by-year improvements in battery efficiency and cost, will bring the price down to $60,000. Starting in 2011, it plans to make 20,000 a year in a new factory in the San Francisco area.

By then Tesla will be in competition with the new generation electric cars from the major car manufacturers. But right now Tesla is out there alone with the only pure electric car that is more than an urban runabout. It has beaten the industry giants by nearly two years.

Significantly, the Tesla company whose chairman is Elon Musk, one of the founders of PayPal and a pioneer of space tourism, has started to recruit executives from the blacksmith motor industry. Mike Donoughe, engineering vice president, came from Chrysler, Chief Financial Officer Deepak Ahuja is from Ford and the design chief Franz von Holzhausen, was the director of Mazda’s US design studio.

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