[Vo]:Upcoming Prius with PV cells in roof

[Jed Rothwell]

There are reports that an upcoming top-of-the-line version of the 
Prius will have an array of PV cells in the roof. There is a 
photograph circulating. I hope it will also be a plug-in hybrid.

The reports say that the PV array will be used "to run the air 
conditioning." Note that Prius air conditioning uses electric power, 
not scavenged mechanical power.

At first glance, putting the PV array on an electric car seems like a 
nutty idea. As we have discussed here, the gap between PV output and 
the energy needed to power the car is so great that this seems like a 
waste of PV and an unnecessary complication that will cause problems. 
However, this idea makes sense in the Japanese climate.

Small PV arrays are widely used in Japan, especially with older cars. 
They are mounted on the dashboard. Actually, just tossed on the dash, 
for two purposes:

1. To trickle charge the battery. They plug into the cigarette lighter.

2. To run those fans that fit in the top of the window. You leave the 
fan running while the car is parked. They keep the rain out and the 
car ventilated. (Actually, I think foil reflectors are better but I 
have not seen many of them in Japan.)

My guess is that the purpose of the PV array in the Prius will be to 
run the air conditioner while the car is parked. That would be a nice 
feature in southern Japan, and in Georgia, too!

Also, when the Prius makes a long stop at a traffic light with the 
air conditioner running full blast, sometimes the motor does not cut 
off the way it normally does. It stays on to power the air 
conditioner. When this happens I usually turn oft the air 
conditioning to silence the motor.

The PV arrays appear to be fairly large, so I suppose they will also 
recharge the batteries with a significant amount of energy if the 
cars left for eight hours in bright sunlight. (Assuming the AC is not running.)

- Jed