Despite the eco-benefits and lower running costs, electric vehicles haven’t quite taken off. So Toyota is betting on hydrogen fuel cell vehicles as the cars of the future, and its latest billboard ad is sparking up conversation around the issue of car emissions by purifying the surrounding air.

Despite being far better for the environment, sales of electric cars haven't picked up. But research suggests that by 2022, they could actually work out cheaper to buy and run than conventional vehicles. Could cutting the cost convince people to start saving the environment?

Though many auto manufacturers and analysts claim that electric vehicles are the future of the car industry, they account for just 0.1% of global sales at present, with low fuel prices causing a slowdown. Is the EV dream fading, or is this just a blip in an inevitable electric revolution?

Tesla didn’t set out just to challenge the automotive sector – it wants to change it. It ranks in the top five brands among motor enthusiasts, and celebrity fans of Tesla include Jay-Z, Ben Affleck and Jay Leno. But how has an electric car company become a cool cult brand?