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It would have been nice if they gave a range of price. I dislike it when they don't, as if they have something to hide.
 

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I don't find it ugly. Besides, it goes on top of the roof where it wouldn't be easily seen anyway.

It would be cool for those that have the bucks to spend to start the market for it, much like the Tesla and the Prius. Someday it will be commonplace and affordable, but it has to start somewhere. At least it gives something back for the investment, unlike many other options and accessories we all tend to go for.
 

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If you read the 'White Paper', You'll see that this is a varieant of the often discussed 'Plug-in' retrofits. It uses the solar cells to charge a separated 48 volt, 3kwh battery (a lead acid in their prototype, NiMh in their kit) and then an inverter to use this source to maintain the charge on the traction battery until their additional battery is discharged.

(Figure from their white paper)
Their aux battery is about the 1/2 the energy storage as the traction battery, but they push it harder so it will about double the EV driving range. Note that they claim 5-8 miles which is somewhat overstated.

The issues are:
  • Price (not given)
    Space taken up in the cargo area
    Added weight
    Expected auxilliary battery life and replacement cost
JeffD
 

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Discussion Starter #7
jdenenberg said:
Their aux battery is about the 1/2 the energy storage as the traction battery, but they push it harder so it will about double the EV driving range.
The existing traction battery in the Prius is only 1.3 kWh, but the computer only lets you have the state-of-charge (SOC) range from about 40% to 80% as an absolute maximum (0.5 kWh). Most often, people get to use from about 70% to 50% (0.25 kWh), as the computer doesn't like letting it cycle too high or too deep.

The added lead acid (3 kWh) is therefore very much bigger than the exisiting traction battery. It's essential as the daily 1 kWh from the solar cell would not fit in the original computer-limited Prius battery.
 

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Clet,

Sorry, I misread the capacity as kamp-hours (old and, weak eyes), but you do need to derate their bateery by the same factor of 2 if you don't want to have to replace the added batteries at regular intervals.

JeffD
 

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clett said:
It's a 225 watt panel, giving up to 1 kWh charge per day for free (5 miles per day free range).
My bet is the 1 kwh will be gone to cool the cabin down when we park under the burning sun, and we need more than 10 years to depreciate the fee.
My another bet is parking under the shade without any solar panel is the best.

[email protected]
 

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1 kwh will be gone to cool the cabin down when we park under the burning sun
If my car is too hot from sitting under the sun, I usually roll down the windows until it reaches outside temperature. It only takes a few seconds.

I don't know whether this add-on would pay for itself in 3 years or 10 but I would not fault anyone who did it. If we all waited until these things were proven to save us money they would never happen. What would happen if we put as much R&D into photovoltaics as we have into computers?
 

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Discussion Starter #11
This kind of thing is useful, because some people (more likely companies or institutions keen to show a 'green' image for PR purposes) will buy them, regardless of payback.

Their experience of this (and PHEV etc) will then filter down to Toyota etc who may one day take notice.

If the 2008/9 Prius emerges with a 3 kWh LiIon battery pack as some insiders expect, then it will be trivial to install an optional solar panel on the roof. Notably, both Toyota and Honda are investing in thin-film solar technologies and Honda have gone as far as to suggest one day putting it on cars. When PHEVs are mainstream, this kind of thing will be easy-peasy.
 

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I think the solar panel molded to the roof curves is pretty cool. Looks nice. Can't tell how they delt with the extra thickness along the edges in the photos though. That could take a lot away from the looks. There are "roll up" solar panels available. They can be glued to boat decks and walked on! They've been available for 5 years or so, so this companies claims are a bit overstated.

I have a small solar panel that I can use in a vehicle, just to maintain full charge of the 12V battery, of course. I just sit it on the dash (being sure to park facing south), and plug it in to my power tap. Well, by small I mean it's 14"x14". Puts out only 300 mA as it's amorphous silicone, not the high efficiency single crystal type. But it was free, so I'm not complaining. ;)
 
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