The R&D departments of the world’s carmakers have put considerable effort into building solar-powered models for over twenty years now. The solar option could well be the shape of things to come for cars, to the same extent as electric power, compressed air or biomass. Not only is it the world’s most plentiful renewable energy source, it also produces zero CO2 emissions, does not pollute and is completely free. Every day the sun produces energy equivalent to ten times the world’s annual crude oil consumption. With around a billion cars in use worldwide, designing vehicles that run on renewable energies is a major technological challenge with lucrative economic prospects.

 

However, no solar models are currently available on the market. In the past two years, both Fiat and Toyota announced the launch of solar-powered models. Back in 2008, the Italian manufacturer promised that its Phylla model (pictured above) would be ready for rollout in Italy in 2010. In the end, the three-metre-long city car, powered by dozens of small solar panels with a range of 200km, was shelved. Despite its many features, including a top speed of 130 km/h and running costs of €1 per 100km, the Phylla will never leave the confines of Turin Airport for the open road, Fiat has disclosed.

 

 

“The Phylla won’t be going on sale to the general public. It was never Fiat’s intention to produce the vehicle industrially; the point was to show people what we can do. Especially since the market has been on course for a fully or semi-electric car for over two years now,” Fiat confesses.

 

Toyota, on the other hand, is said to have been working secretly on a solar model for the last year. The Japanese manufacturer is reportedly looking at working round the problem to some extent, with mixed solar-energy sources, using panels on the car itself and on the garage roof.

 

Whilst electric cars are now raring to go, solar vehicles are dragging their wheels. According to Gabriel Plassat, an engineer at the Transport and Mobility Department of the French Environment and Energy Management Agency (Ademe), the obstacle to selling solar-powered vehicles is easy to explain, on account of “the energy required to run a car. Even if we covered the entire available surface area of the car with solar panels, this wouldn’t be enough to get it running. Solar vehicles’ requirements are too great. Having people believe that such solutions exist is both misleading and dangerous, for it implies that there are solutions for everything and that we’ll be able to carry on driving around as before.”

 

Though unsuitable for cars, fully solar-powered systems could be more compatible with lorries, “whose surface area is far greater,” Plassat says. “But in the end, the most promising alternative is still the solar-electric hybrid.” In this case, the energy produced by the solar panels would be used to power up the battery, air conditioning, electrical circuits and the radio. Luxury car manufacturer Venturi has already tested this “more realistic” scenario. The French marque, now based in Monaco, has come up with the Eclectic, a solar-electric car. At €15,000 excluding VAT (batteries supplied), the three-seater hybrid, due to launch in 2011, may well win over drivers who primarily make short journeys. With a range of 50km, the Eclectic is proof of the problems facing manufacturers in their efforts to improve the performance of “solar only” cars.

 

“It isn’t possible to produce a solar-only car at the moment, for technical reasons. The most proficient solar panels have a yield of just 20%, which isn’t enough to cover the car’s energy requirements,” says Christophe Sauné, marketing assistant at Venturi. Carmakers also put the blame on solar-power storage problems. They criticize the energy losses, which can be as high as 80% depending on battery type.

 

If panel efficiency and storage capacity are not improved, driving a solar-powered car will remain a pipe dream. The far more efficient “all electric” car clearly leads the way. And if proof were needed, this year’s International Motor Show, which has just opened in Geneva, features over ten electric models. At the front of the queue, Bolloré has confirmed the pending launch of its Blue Car in 2010. The newcomer will combine solar and electric drive, thanks to panels fitted to the roof.