An enterprising and eco-friendly Canadian engineer has modified his Toyota Prius by adding solar panels onto its roof and an auxiliary battery system. Steve Lapp's prototype enables his Prius to run on electrical energy for longer, giving an overall fuel efficiency improvement of 10percent in tests so far. Lapp recognizes that the small solar panels which can fit onto a car roof have limited capacity and cannot power the car exclusively, but says that "for June and July in Kingston Ontario, about 6kWh of energy from the sun strikes each square metre of horizontal surface. If we install two square metres of photovoltaic (PV) panels on the car and we collect 10percent of the energy from the sun as electricity (well within present PV efficiency) we can theoretically go about 8km each day on just the sun's energy. If we drive 24km on a sunny day, that is enough to reduce our gasoline consumption by 33percent. This would take the Prius from 47mpg to 71.2mpg." Lapp's Prius cannot, however, charge up its batteries when the engine is switched off. He predicts his system can achieve fuel economy improvements of up to 20percent with further minor refinement, and his Prius is now returning an average of 59mpg - an improvement of well over 10percent from the 'real-life' economy figures usually reported.

Toyota, meanwhile, does not have its own plans to make a solar-boosted Prius, though it is considering manufacturing the model at the factory it shares with GM in Fremont, California. This would help meet the huge demand for the Prius in that state, according to the Wall Street Journal, though production alongside the hybrid Camry in Georgetown, Kentucky, is also under consideration. (www.greencarcongress.com)

hm.. more ppl mod their green cars interesting...



http://www.channel4.com/4car/news/ne...31&ref=archive