This one is spreading around the "sustainable blogosphere" faster than Avian Flu -- Green Car Congress has a report on the efforts of a Canadian engineer to add photovoltaic panels to his Prius. The goal isn't to make the Prius entirely self-sufficient, but to boost its overall efficiency: the engineer, one Steve Lapp, reports a better than 10% boost in mileage using a rough, non-optimized version of the system, from ~52 miles per gallon to ~59 mpg. The "PV Prius" is very much a proof-of-concept demo -- I'd imagine that Toyota's designers will be appalled at how the big solar panel breaks up the smooth lines of the car -- but it's a good example of how the integration of local generation has the potential to enhance overall energy efficiency.
There's still much work to do in order to figure out right number of panels, energy flow to batteries, and myriad other technical details. There's also the larger question of the overall efficiency of the photovoltaics, and whether future adoption of cheaper, low-efficiency polymer PV or expensive, higher-efficiency nano PV would have a better payoff. Still, expect some day to see "Sun-In Hybrids" shoulder-to-shoulder with "Plug-In Hybrids."
If I were wealthy id have a few panels on my hydrid suv simply to ensure no matter what I can always limp home or power the onstar system so I can call for help.
Surprising that the solar panels don't cause drag. Maybe they do and that's why the increase is small.
Every little bit helps. Planning/cooridinating errands, turning off lights when you leave a room, turning the thermostat down in the winter and up in the summer, tune ups, tire air pressure, simply keeping your cars exterior clean has a small effect. I like to call small little things we can do, intelligent conservation. We don't have go out and chain ourselves to a tree. But if we can increase our mileage by 10 + % ? Sure; Do it when you get your tax refund, or maybe when you've got some overtime pay coming.
Lots of people doing small little things can have a huge effect. We all do things locally, and they have an effect globally, we just can't see an immediate effect.
The Prius is a great piece of enginnering. Just take it a bit farther. The Prius + plugin concept is a good start. Adding solar panels helps. Making the car E85 capable seems to make sense too.
I have a 04 prius and am geting 59 mpg imperial or 4.6/per 100kms all the time, and dont see the need for solar panels.