Thursday, March 19, 2009
The Underwhelming Solar Prius
The optional solar roof on Toyota's 2010 Prius may not provide a watt of mobility.
By Peter Fairley
| A solar roof will simply ventilate the 2010 Prius. |
The solar roof that Toyota is offering as an option on its next-generation Prius hybrid sedan may be even less useful than expected, according to a report in the specialty publication EVWorld. The solar panels, reports EVWorld, will add not a microwatt of charge to drive the Prius.
Last summer, Technology Review looked at the potential impact of adding a solar roof to the Prius when rumors of Toyota's plans first emerged. The clear conclusion of the experts was this: keep solar panels on rooftops, where they can be tilted toward the sun for maximum efficiency. A solar rooftop would be just a "marketing gimmick," said Andrew Frank, a plug-in hybrid pioneer at the University of California, Davis, and chief technology officer for UC-Davis hybrid-vehicle spinoff Efficient Drivetrains.
Toyota, it turns out, won't even bother plugging its solar rooftop panel into the 2010 Prius's nickel-metal-hydride battery. EVWorld editor Bill Moore, citing a conversation with Akihiko Otsuka, chief engineer for the Prius redesign, writes that
Toyota tried it and apparently discovered that for not-entirely-well-understood reasons, connecting the PV panels to the battery turns them into an "antenna" of sorts, which at the very least seems to disrupt the car's radio.
So Toyota left it at that. The solar roof will simply help keep the car cool when it's parked by running a fan to ventilate the car. For the average driver, that could be somewhat useful for, say, half the year.
I spoke with Otsuka while reporting from the Geneva Motor Show earlier this month, and learned that Toyota engineers are targeting a range of 20 kilometers in the EV mode for the plug-in version of the Prius. The lithium-battery-equipped vehicle is to be offered to Toyota's fleet customers by the end of this year.
That would mark a boost over the 10-to-15-kilometer range offered by the nickel-metal-hydride-powered plug-in Prius that Toyota has been testing. But it remains just a third of the 60-kilometer range that GM is promising for its Chevy Volt plug-in hybrid, which is due out next year. GM's design has already set off a debate over the cost effectiveness and efficiency of carrying the battery capacity that such range requires.
Massachusetts Institute of Technology
Comments
nekote
03/20/2009
Posts:139
Tysto
03/27/2009
Posts:26
Not just cars either, boats and planes too. While most solar cars are special vehicles and expensive or have few amenities, times are changing fast.
Solar cars race across America, Australia, and other countries every year, and they are not slow. Solar boats have crossed the Pacific and Atlantic. A solar airplane has flown across America. Practical? The University of Central Florida has a solar powered car they drive 20 miles a day, and it has doors and windows, and windshied wipers, and even air conditioning! There are over 1,000 solar powered boats and ferries operating around the world.
PV's on cars are not perfect for everyone, but they are getting better fast.
See a growing list at Self Powered Electric Vehicles
Luckenbach
03/21/2009
Posts:2
But I still want a PV cell on my car roof to cool or heat it to take the edge off the weather.
Tysto
04/06/2009
Posts:26
ganderc
04/07/2009
Posts:1
BrandonPaul
09/30/2009
Posts:2
my toyotadealer (botman toyota holland) doesn't understand anything about solar cells. The vent opening goes after 10 minutes with the motor off in the solar vent position and then the fan does pffft and stops. After that this will be repeated.
no cool interior for me. The garage has no clue and wants the car when the sun shines, they got the car in the winter on a bright sunny day.
al very frustrating how they handel it. When Toyota sells a car with a sun roof they must also have a test facilitie where they can test the system.
dzjon
03/12/2010
Posts:1