Photovoltaic solar-panel rear spoiler

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I am considering the SV Leaf since I want to have the WINGS option available, but I'm curious to know the actual benefit that the Photovoltaic solar-panel rear spoiler provides on the SL model. I read that it's purpose is to power the car's accessories and not the car battery.

Does anyone know if the Photovoltaic solar-panel rear spoiler provides any benefit to the range of the car?

I personally like to listen to the radio while driving and having the AC turned up all the way in the summer and the heat in the winter (I live in TX).
 
The rear spoiler PVC panel will keep the 12V battery topped off if you leave the car parked in the sun. Apart from that - at least for our 2011 - I am not aware of any other contribution.
 
...but of course, by leaving your LEAF in the sun to trickle-charge the battery (especially in the summer), you're probably doing much more damage to your (much more expensive) traction battery. Better to park in the shade and forego the solar panel, since the traction battery automatically "tops up" the 12v accessory battery when necessary.

In short, the solar panel is "marketing fluff". :roll:

Full disclosure: I have one on my 2011 SL model... :lol:
 
I've always wondered if the solar panel isn't really nice because of how poorly the Leaf does keeping the 12v battery charged up.
 
You can blame me for the the solar panel :D More on that later.

If you watch the CAN bus while driving, you can see occasionally see the DC-to-DC converter running to charge the 12V system. This pulls a bit of energy out of the traction pack and charges the AUX battery. If you have the solar panel, this would happen less often, so you could get an extra bit of range. How far? Here is a quick napkin sketch:
Assuming the panel makes 100Wh on a given day (this is optimistic) and that completely offsets 100Wh from the traction pack, you'd have that much more for driving. Assuming 250Wh per mile, that will get you 0.4 miles.

If your car is kept under covered parking during the day, it would be even less. So the solar panel is a token, albeit an important one I would argue.

I got to meet with Mark Perry and Nissan execs from Japan in 2008 and I told them the story about whenever I had my electric truck at an EV event someone would suggest putting a solar panel on there with a statement like "This runs on electricity, solar panels make electricity. You should put one on there and just drive all day long." I would explain solar related things like available surface area, angle, and efficiency details. Often during this explanation their eyes would glaze over. So eventually, I changed to just saying "Well, I have solar on my house. It works better there since I never park my house in the shade."

I told the Nissan folks that they could avoid a deluge of email in their inbox from well intentioned, uninformed people by adding a solar panel; even if it is just a single small panel that is only offered as an overpriced accessory. It does not need to add any range it just needs a token function such as running a cooling fan. This gesture would make some customers happy.

I also suggested the range rings on map and asked for 3G charging station location updates since the infrastructure would be growing quickly during this time and I would not want to schedule dealer appointments for map updates each month. I was happy to see that Nissan did all of these. I wrote about all the things I suggested here.
 
patrick0101 said:
I wrote about all the things I suggested here.
So you're the one to blame for the weak regen!!! :p

From that blog post in the section with braking spelled wrong:
My recommendation to Nissan was to keep the regen light until the brake pedal is actually touched. This makes it much easier to hypermile coast and extend the range.
Gaaahhh! You are the bane of existence of nearly all LEAF owners here! We could have had full-off-pedal regen had you suggested it instead of the opposite!
 
Why not for say...1K add an option where the entire roof is a PV panel which feeds the main battery. Even if net effect is small (say 1 mile of range with 10 hours of direct sun light), city dwellers with street parking would get a minimal range increase, and need to seek 3rd party charging a little less often.
 
DougWantsALeaf said:
Why not for say...1K add an option where the entire roof is a PV panel which feeds the main battery. Even if net effect is small (say 1 mile of range with 10 hours of direct sun light), city dwellers with street parking would get a minimal range increase, and need to seek 3rd party charging a little less often.


Was talking to a guy with a Fisker Karma this weekend, and noticed his entire roof (fairly big roof) appeared to be all solar cells.

Anybody know anything about that?
 
DougWantsALeaf said:
Why not for say...1K add an option where the entire roof is a PV panel which feeds the main battery. Even if net effect is small (say 1 mile of range with 10 hours of direct sun light), city dwellers with street parking would get a minimal range increase, and need to seek 3rd party charging a little less often.
You realize that "10 hours of direct sunlight" is like 3 or 4 days right? You don't get 10 hours of direct sunlight in one day anywhere.

The fisker karma roof charges the aux battery as far as I know (read or heard that somewhere don't remember where...).
 
drees said:
patrick0101 said:
I wrote about all the things I suggested here.
So you're the one to blame for the weak regen!!! :p

From that blog post in the section with braking spelled wrong:
My recommendation to Nissan was to keep the regen light until the brake pedal is actually touched. This makes it much easier to hypermile coast and extend the range.
Gaaahhh! You are the bane of existence of nearly all LEAF owners here! We could have had full-off-pedal regen had you suggested it instead of the opposite!

I doubt that most Leaf drivers (including me, and I have EV experience with full regen, having ridden an Oxygen Lepton for a decade) would enjoy the car with only full regen available. Normal (aka "Sport") mode makes the car vastly more fun to drive in most situations, and with a light foot you use little more energy than in Eco mode, assuming the climate control is off. I'd like to thank Patrick (?) and Nissan for giving the car a "Pleasure to Drive" mode. The only tweak I'd suggest is to make the climate control level independent of mode, and have a separate "Hi/Lo" switch for that. This would allow us to drive in 'Sport' with less energy drain from the CC as desired.
 
DougWantsALeaf said:
Why not for say...1K add an option where the entire roof is a PV panel which feeds the main battery. Even if net effect is small (say 1 mile of range with 10 hours of direct sun light), city dwellers with street parking would get a minimal range increase, and need to seek 3rd party charging a little less often.
It has been said before: the best place for that solar panel is on a house roof, or similar location, where it can produce a lot more electricity than when on the roof of a car.

The downsides of a PV car roof:
• Weight.
• Manufacturing complexity and attendant costs ($1k is likely to be way low)
• Possible reduction in aerodynamics of the car.
• The car roof is rarely pointed in the optimal direction for solar electricity production.
• Fragility. Most types of PV and attendant wiring are not designed for shocks and vibration over an extended time.

Can it be done? Yes, of course. Should it be done? No, the costs outweigh the benefits by a wide margin. Put the panels on a house or carport instead.
 
One of the reasons I did NOT get an SL was the solar panel. It didn't feed the traction battery and I felt I could get a better 12v battery down the road if I really wanted it (and I did--see my sig); I also figured it would be more trouble than it's worth if it was ever cracked or damaged. The other reason was I didn't want QC (at that time you had to get an SL to get QC).
 
drees said:
Gaaahhh! You are the bane of existence of nearly all LEAF owners here! We could have had full-off-pedal regen had you suggested it instead of the opposite!
I have changed my tune on regen since I talked to them & wrote that. After driving a Tesla Roadster for even a short time it is easy to get used to "single pedal driving". And to be fair, I was just one voice. I am sure they wanted the car to feel familiar and that is why the regen is the way it is.
 
We've had discussion on larger solar panels on the roof of a Leaf and their benefit (or rather, lack of) at http://www.mynissanleaf.com/viewtopic.php?f=27&t=6316" onclick="window.open(this.href);return false;.

Re: light regen while off the go pedal and not on the brakes, the Prius does that too. I don't recall on my mom's Altima Hybrid, but I think it also has that behavior.
 
KillaWhat said:
Was talking to a guy with a Fisker Karma this weekend, and noticed his entire roof (fairly big roof) appeared to be all solar cells.

Anybody know anything about that?
JeremyW said:
The fisker karma roof charges the aux battery as far as I know (read or heard that somewhere don't remember where...).
mwalsh said:
The primary function of the Fisker's roof was to run the climate control. But it did put power into the battery pack, giving a theoretical 1 mile of range for every day in full sun.
Yes, I discussed the PV on the roof of a Karma with an owner also on Saturday, as well. Here is what I learned:

- The PV array on the top of the Karma looks really cool (like everything else on that car!).
- I counted the cells. There are 80. If they are all in series, that would give a peak power voltage (Vpp) of about 50V. As such, to run the 12V systems, there would either need to be a buck converter in place or this is one inefficient PV system which would massively overcharge the battery when full.
- As mwalsh said, owner said many believed it was to run the climate control system on hot days to cool the interior.
- Owner said he has never seen the climate control come on and he did not know how to enable it.

Regarding the LEAF PV array: IIRC, we have at least one report of a LEAF SL 12V battery going dead while it was parked outside.
 
[youtube]http://www.youtube.com/watch?v=5WsIHEb9F80[/youtube]

[youtube]http://www.youtube.com/watch?v=DSChzJ327Rg[/youtube]

[youtube]http://www.youtube.com/watch?v=IcJhv_OQC2o[/youtube]


Fisker Karma solar roof production to begin courtesy of Quantum
solarmnl


The Karma includes as standard a solar paneled roof manufactured by Asola Advanced and Automotive Solar Systems GmbH, a Quantum Technologies affiliate, to aid the cabin climate control system. The solar roof is capable of generating a half kilowatt-hour a day and was estimated to provide up to 4 to 5 miles (6.4–8.0 km) of additional range a week assuming continuously sunny days; however, the solar panels as delivered only recharge the 12-volt lead-acid accessory battery. Additionally, Fisker will offer a set of solar panels for the garage/house which may charge the Karma without the benefit of conventional electrical sources (e.g. 'off the grid').
 
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