Solar generator on PV roof?

Not practical. There is not enough surface area to generate the current you would need.

 

Yep. The optional solar roof on current Priuses only generates ~60 watts (IIRC) at best. 1 horsepower = 746 watts

 

you might charge your cell phone tho...

 

With a solar panel and a small charger you can keep the 12V battery in a good condition when not driven for a longer period.

 

John From Australia has flexible PV panels on his bonnet and roof, gets ~300 watts of power. parked all day at work he gets ~2.4kwh of charge, around 9 miles of EV range.

 

i 've seen some solar cars where a large footprint of panels is mounted above the car. but i'd be happy with 9 miles of solar charge!

 

That's australia, but still that's really pretty good, no joke.

 

Yeah, it's completely not worth it (from a cost point of view) since you're displacing wall-power, and that's not very expensive. As electricity gets more expensive as we all start using more of it, solar setups will hopefully become both more common and more efficient.

 

Um, that's a theoretical high, under absolute perfect conditions. Call me a doubting Thomas, but since it's not always sunny, and since hot weather degrades efficiency, or, since the sun is only perfectly perpendicular in the sky for a few minutes a day, or since flex panels never face the same direction, and since there's a percentage of line loss, the true wattage will likely be less than 60% of the illusory perfect condition, at any given time, averaged ... and may be even greater (losses). That's speaking as a 2 1/2 years PV user. A super high efficiency panel (appx 9 or 10 square feet @ 20% efficiency) may generate 300 watts in those perfect conditions ... but all the long term production contracts for those are typically held by european countries that grasp their value. Flexible film is nowhere near that level of efficiency. You're usually looking at about 10% efficiency with flex film.

 

Yes this is the best option i have ever seen....

 

I looked into solar roof and to just get enough cells to cover the roof with converter runs over 4000 dollars. As much as I would like to add this feature to my Phev it is in no way cost effective.John in Australia stated on enginer forum that if when asked how many years it would take to recoup his initial cost on system his answer was it would take until his granddaughter started to drive

 

Wow! I'm very interested! Have you got further details and/or pictures?

 

I have attached my project sheet for my Solar Prius. It is designed to be used with an Enginer Kit so unless you have a Enginer Kit it would not be of much use to you.

 

The PV panel name (TSM-30) ... I see these "Thin-Film" panels are manufactured in China? Your spread sheet states the panels are 20.80% efficient? How can that be? I have NEVER seen thin film spec's claiming efficiency higher than 12% and most of the best are less than that:
Are Thin-Film Solar Efficiency Standards Unfair? — Cleantech News and Analysis

Even so, kudos for all the hard work!

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People often ask me why my Nissan Leaf doesn't have solar panels, and I explain the same thing - that it just doesn't make enough power to make a difference. However, in the case of the Prius PHV I think it may make sense. Even the regular solar-roof probably could produce 1 KW per day on a sunny day. Thats enough to go 3 or 4 miles. Now that doesn't sound like a lot for a Nissan Leaf, but when the Prius PHV only does 13 miles to begin with, that is a big improvement. If the panel were made twice as large, then it could do maybe 8 miles. So imagine this, you leave your home with 13 miles range. You get to work and gain an additional 8 miles before you go home. That is pretty significant.

 

First, you probably mean 1kWh ?? The Prius PV panel is only rated for 60 ish watts under perfect conditions ... otherwise you're lucky to get 50 ish watts out of it - so no, it's unlikely you'd get any where near 1kWh. More likely you'd be lucky to get 40% of 1kWh ... or ONE 400 watt hour.

 

You are correct, I meant to say 1 Kwh. Okay, so the current solar roof can deliver maybe 0.5 Kwh per day. But if they doubled the size (eliminating the sun roof) and maybe added some more on the hood, I think it is reasonable that you could generate somewhere between 1 to 2 Kwh per day. That would still give you several miles.

I wouldn't be surprised to see this as a feature on some EV or PHEV within the next few years.

 

This is faulty logic. The percentage contribution is not relevant. By this logic putting PV panels on an F150 would be even better, since it goes zero miles on electricity.

Tom