TechnoidNash writes: Riversimple has been developing a hydrogen car with the support of a 2 million grant from the Welsh government. The result of their efforts? The Riversimple Rasa. A hydrogen car with a claimed fuel economy of 0.9L/100 km (250 mpg). The Rasa can reach up to 96 km/h (60 mph) and has a range of 483 km (300 miles) on a 1.5 kg tank of hydrogen.