The Ford Th!nk City

Cars undoubtedly make life easier, but nobody could ever claim that they're good for the environment. That's why an increasing effort is being made to develop alternative options to fossil fuel.

The Ford Th!nk car looked like one of the best green rivals to the internal combustion engine. It had a top speed of 50mph, a range of 53 miles, and cost just 45p to refuel from a household socket. Unfortunately, Ford abandoned the project in 2002 due to poor sales.

Instead, the car industry is embracing the idea of hybrids - cars that switch between petrol and electricity. Ferdinand Porsche engineered the first successful hybrid electric car in 1928. The Toyota Prius is the most popular current example, with over 200,000 already sold worldwide. In fact, Leonardo Di Caprio owns one and Tim Robbins and his wife, Susan Sarandon, turned up to the 2004 Oscars in their Prius, which cuts down on emissions by up to 75%.

Of course, it's still a long way short of solar-powered cars, which produce zero emissions. Built by Dutch University students, the Nuna II won the 2003 World Solar Challenge in Australia - a race for cars that are powered only by sunlight. The car travelled 3,000km across the Australian outback, from Darwin to Adelaide, at an average speed of 97kmph (60mph).