 Imagine a London where, instead of firing up your noisy diesel or petrol saloon and blasting a cloud of fumes into the air as you set off for work or the shops, your car glides silently, elegantly - fumelessly - along the road. Rather like rolling downhill, with the engine off.  Pipe-dream? Not if Mayor Boris Johnson's plans to make London the electric car capital of Europe come to fruition, and the good news is that our journey into this bright, clean future is already well under way.  a decade ago just 9,000 pure electric and electric hybrid vehicles were registered in the UK, but today more than 72,000 are in use according to the Driver and Vehicle Licensing agency. Now, experts are predicting, the number of "EVs" could rise to 85,000 by 2015, racing on to 600,000 by 2020.  Better news still is that the capital is at the forefront of this technological revolution, with 17,000 EVs registered in London - some 23.5 per cent of the nation's total.  Mr Johnson painted a compelling picture of London's green future transport network when he switched on the capital's new electric vehicle scheme - Source London - in May. The capital's first city-wide electric charge-point network and membership scheme, it makes it simpler for EV owners to charge up while on the move. Promising a total of at least 1,300 charge points by 2013, it will even outstrip the number of petrol stations in London.  "I want to rapidly accelerate the uptake of electric vehicles and make London the epicentre of electric driving in Europe," he pledged. "Increasing numbers of motorists are opting for cleaner, greener electric transport, delivering a host of benefits to the driver. This is set to deliver considerable environmental benefits to our city."  Simultaneously announcing a 100 per cent discount on the congestion charge for electric vehicles, Mr Johnson reminded motorists that there were further savings from the Government's ?5,000 consumer incentive grant available for electric cars, which also qualify for nil-rate vehicle excise duty. But are his targets realistic? One man who has made environmental motoring his speciality is Jay Nagley, managing director of automotive analysts Redspy automotive. "The target of 600,000 EVs, including hybrids, by 2020 is certainly achievable," he said.  "Every major manufacturer will make a plug-in hybrid, starting with a plug-in version of the Toyota Prius, a new plug-in Ford and VW Golf, in 2013. Plus the extended-range Vauxhall ampera hybrid will be on sale next year. all the car makers are following a similar script."  Society of Motor Manufacturers and Traders figures reveal steady growth in electric car registrations, with 289 put on the road last year compared to 450 so far this year.  already, of course, it is possible to buy or lease an impressive range of electric cars including Peugeot's iOn, Citroen's C-Zero, Mitsubishi's i-MiEV, Nissan's Leaf and Smart's fortwo EV, to name but a few.  But it couldn't have happened without support from the power industry and one of the breakthroughs was the installation by EDF Energy - a leading player in the development of electric vehicle technology and the UK's largest producer of low-carbon electricity - of around 100 public charging points across the UK, many of them in London. It has been working with Elektromotive, a leading provider of EV recharging infrastructure, since 2007.  "Britain is in the enviable position of leading the electric vehicle revolution in Europe and the considerable momentum we have built up will not be lost," promised Calvey Taylor-Haw, founder and managing director of Elektromotive. "Elektrobays in London are generating an extremely high level of round-the-clock usage, which provides a clear template for how the creation of a proven infrastructure is essential for electric cars to become widely accepted. Our journey into a clean future has well and truly begun."  ELECTRIC VEHICLES  What they cost - and where to charge them  INFRaSTRUCTURE  Will you be one of the 600,000 motorists whizzing around in an electric car in 2020? Very possibly, but according to research by EDF Energy and EV maker smart, your support is not unconditional.  a survey they conducted shows that two-thirds of Britons are willing to consider an EV, but only if the right infrastructure is created first.  Over three-quarters of 500 people surveyed also said that petrol/diesel emissions needed to be lowered, with 87 per cent calling on councils to invest more in away-from-home electric recharging points. Other findings were that 69 per cent believed that owning an EV would reduce their carbon footprint, while 61 per cent said it would cut their motoring costs.  In fact, the typical annual electricity cost for an EV, say EDF Energy and smart, would be ?236 based on three charges a week - a saving of well over ?850 a year compared to a conventionally powered car.  EDF Energy has been investing in low carbon electricity generation, while consulting with central and local government and car makers to ensure it is ready to meet the growing demand that the thirst for EVs will place on the infrastructure. It is investing to ensure that there is sufficient generation of electricity with its plans for four new nuclear plants, and it has been actively engaged in influencing the standardisation of EV recharging at UK and European levels, to maximise the carbon and cost-saving benefits of electric vehicles.  The energy firm is also working to ensure it can offer customers bespoke recharging solutions at home and in the workplace, where it believes 90 per cent of recharging will take place.  But could growing demand for electricity by 2020 swamp the system? EDF Energy says that at this take-up, the additional demand will be less than one per cent of total electricity demand, so it will not necessitate a proportionate increase in generation capacity. Longer term, it adds, demand will be managed through off-peak tariffs and smart meters, enabling EVs to maximise their carbon-saving potential.  RESEaRCH/RECHaRGING  Driving a silent, electric car will certainly cut your motoring costs if you decide to set out on your own "green" journey; energy costs for an EV are around 3p a mile, compared to 8p for the most economical diesel. But there is more at stake than that, with detailed research by EDF Energy with Peugeot UK and Citroen UK showing that the take-up of clean, electric transport, combined with low-carbon electricity, is crucial to Britain meeting its carbon reduction targets. Based on today's grid mix, "pure" electric cars deliver 30-40 per cent carbon savings compared to a petrol vehicle. But as the grid decarbonises further, these savings will also increase. Underlining its investment in low-carbon generation, EDF Energy was selected by the manufacturers of the Peugeot iOn and the Citroen C-Zero to offer new-car purchasers a "fully bundled" recharging package for ?799. Following a free home survey and the installation of a dedicated charging point, drivers can benefit from faster charging times of more than 35 per cent.  The EV point package ensures households cut costs by receiving 20 per cent cheaper electricity during evenings and weekends, so that charging an iOn or C-Zero from empty will cost ?1.93 - around three pence a mile. "We are encouraging millions of people and businesses to make changes that will contribute to a more sustainable Britain before the attention of the world turns to our shores for London 2012," said Bethan Carver, B2C Product Development manager at EDF Energy.  RaNGE/TRIaLS  Every new technology creates a language of its own, and the 