# Toyota Adds Solar Power To Hybrid

### from the what's-wrong-with-wind-power? dept

Toyota, already considered a leader in producing hybrid gas-electric vehicles is apparently preparing to make that hybrid a bit more hybrid: it's going to add solar panels to some models, using the solar energy to power air conditioning. It's not much, but it's a start. I've actually been fascinated with solar vehicles since the fifth grade (yikes) when I convinced some engineers at GM to send me some cheap solar panels to build a tiny solar-powered car (Chrysler ignored my letter, Ford sent a form letter in response). While GM had invested in some prototypes and took part in various solar powered car contests, the technology has never been good enough to do very much at a practical level. Now, how long will it be until Toyota figures out a way to use wind power as well?

Filed Under: hybrid cars, prius, solar power
Companies: toyota

1. Gelbstoff, 8 Jul 2008 @ 1:30pm

### Re: Enery Calculation provide Reality Check

Dear Joe J.
Check your numbers. I think that irradiance at the top of the atmosphere is about 1,370 W/m^2. At the surface, the global average is about 340 W/m^2, but lets call it ~200 W/m^2 to be on the pessimistic side. So, based on your calculation we get about 5.7E7 Joules. Now, lets use a more realistic 30% solar panel efficiency and we are down to 1.7E7 Joules. This case is worst than the one you presented. However, you cannot do an apples to apples comparison. As you probably know, you do not get a 100% transfer of energy to motion when you burn the fuel. I think that the theoretical limit for internal combustion engines is about 20%, so you are left with 26MJoules. From this you have to subtract the loses due to friction in the drive train, and then there is the drag, and do not forget the energy needed to move the fuel in the fuel tank. I am too lazy to do the numbers, but I suspect we are down in the 10's of MJoules. On the other hand, the solar panel is not intended to run the car, it will just be happily charging the batteries of the Prius (with loses only due to transmission over very short distances) at no extra cost to the environment and the consumer. Nothing wrong with that, and my pant are definitely wet with anticipation.

Subscribe to the Techdirt Daily newsletter

Comment Options:

• Use markdown for basic formatting. (HTML is not supported.)
• Remember name/email/url (set a cookie)

Techdirt Gear