Should Model S have a solar panel?

[JRP3]

High temperatures reduce panel efficiency and reliability. Solar cells age more rapidly when hot, roughly doubling the speed at which they age for every 18F so heat buildup is a major problem when integrating solar cells into a vehicle roof.

That may be the first legitimate issue anyone has brought up, though I'm not sure it's a major problem. Stationary panels are expected to operate for 30+ years, vehicles typically for half as long.

I'm hope Tesla and Solarcity will offer panels and home batteries to buffer daytime sun for nighttime charge?

Which will still do nothing for you when you are away from home or can't put solar on your apartment.

 

[Danal]

Avoiding long-term-vampire-when-parked syndrome is a quite nice use case for solar. If you already have a Pano roof, adding solar to the back half seems fairly easy. Google shows TONS of flex panels, ranging from pre-made kits (which would probably not work) to OEM stuff. Here is one of many examples: PowerFilm They may or may not have exactly what should go on a Tesla roof; there are plenty of others if they don't.

That leaves a couple of questions:

1) Is there enough area to actually gather enough solar to indefinitely offset vampire?

2) Exactly how should the power be injected back into the car? Directly at the battery? There are a ton of "solar panel>controller>12V Lead-Acid battery" available off the shelf. Any of them suitable?

 

[tga]

Wow, way to judge without knowing my situation whatsoever. I have no dedicated parking at home. Pray tell, how can I leave my car unattended on a street in Boston for 6 months when I would have to move my car every 2 weeks for street sweeping?
Also, your last sentence is absurd, as I park her outside every day of her life (again, I have no garage). She's doing fine.

Admittedly, "downright dumb" is a bit extreme, but even "economy" parking at Logan will run you ~$500/month. If you don't have to fly out right now and can plan ahead, you should be able to store the car, indoors, on a 120V maintenance charge, for a lot less.

I know people in the greater Boston area who store cars over the winter for a lot less. If you ever need to head out for that length of time, PM me and I'll try to put you in touch with some more reasonable storage options.

 

[Rheazombi]

Admittedly, "downright dumb" is a bit extreme, but even "economy" parking at Logan will run you ~$500/month. If you don't have to fly out right now and can plan ahead, you should be able to store the car, indoors, on a 120V maintenance charge, for a lot less.

I know people in the greater Boston area who store cars over the winter for a lot less. If you ever need to head out for that length of time, PM me and I'll try to put you in touch with some more reasonable storage options.

Some clarifications I would like to make regarding this scenario:
Thanks for the idea of using a storage facility, I'll have to look into that. How much cheaper would it actually be though? The Logan price sucked, but I was able to get them to cut it in half once I explained my scenario to the garage manager. It ended up being a drop in the bucket compared to the rent I paid on an empty Boston Back Bay apt for 6 months, not to mention the cost of the trip itself.

In my scenario, I DID have to fly out within 3 days and storing the car was the furthest thing from my mind. Was far more concerned with packing, setting up hotels, etc.

In my case I didn't know how long I would be gone. It was supposed to be 3 weeks but became 6 months. Again, storing the car would have been pointless for all I knew.

I used 6 months as an example because it had just happened to me and so I could relate a specific experience and give a real world example about how things aren't always so easy. But by no means would a solar roof only have helped MY weird situation. People park for 1-2 months all the time in long term parking at the airport. Storing their car in a facility miles out of town would be a needless hassle to them. These people would benefit greatly having a solar roof of some kind.

Not to mention, the vampire drain I dealt with this winter was bonkers. Even a little bit would have helped.

In any case, aaronw was being unnecessarily rude and condescending especially since he doesn't know me from Adam. In fact, there is way too many assumptions in this thread about people's lifestyles. Some people would find this feature incredibly useful and some would find it incredibly redundant.

Sorry if this post is slightly derailing.

 

[omgwtfbyobbq]

That may be the first legitimate issue anyone has brought up, though I'm not sure it's a major problem. Stationary panels are expected to operate for 30+ years, vehicles typically for half as long.

I don't think it's a huge issue, especially since the flexible CIGS panels seem to be in the ~$.50c-$.75c/W range. Even if they go kaput after ~15 years, that's still 2c/kWh, which is great for charging on the go. At the same time, stationary panels are usually warrantied for output at 30 years, not functionality. They'll produce power for decades after that, just at reduced levels. Granted, the advantage for smaller more efficient cars is better. Probably something like 10-miles of range per day for a Leaf/i/etc... But every little bit helps even for larger vehicles.

 

[Khatsalano]

I just wouldn't want one ... why would I ever park my Tesla outside, under the hot sun and in the elements, unless I had no other choice?

- K

 

[smilepak]

If a Prius and a Leaf can have solar power, why not on a Tesla....

 

[Beckler]

The more I think of this, I think it should be an option in the future. With solar city now claiming 22% efficiency and if we imagine the entire car covered (hood, roof, maybe even rear window option too - have a rear view camera only...is that legal? ), it's probably fairly useful to have a best-case rate of say 10 miles self-charging range per day. For very light drivers without garages they'd never even have to charge. It would just be a semi-useful option though (for some users probably really useful), just like premium sound or other ones you don't need. Would be like $5-10k depending on how much coverage you choose but a fun thing to have I think!

 

[aaronw]

Putting that much solar on a car will be hideously expensive since unlike rooftop panels the car is curved. Add to it the fact that it needs to stand up to hail and the elements. Additionally, car mounted solar is far from optimal. Rooftop solar is typically pointed towards the sun, i.e. south in the US. It has been estimated that the solar installed on the Fisker Karma cost around $5000 and that's just in the roof. It only provides around 100 watts of power. I read the ROI is around 500 years and it adds at most around 1/2 a mile of range per day. Adding it to the hood would be a problem since you don't want it to crack when hit by rocks and whatnot. I don't think it even charges the main battery. It just keeps the 12v battery topped off and helps cool the interior of the car.

For the amount of money it would cost to add it to the car you could buy quite a few panels and microinverters.

 

[Rocky_H]

With solar city now claiming 22% efficiency and if we imagine the entire car covered (hood, roof, maybe even rear window option too - have a rear view camera only...is that legal? ), it's probably fairly useful to have a best-case rate of say 10 miles self-charging range per day.

Apples and oranges. Solar panels are in two different categories: rigid flat silicon panels or thin film solar.

Flat panels: high energy efficiency, but heavy and not flexible, so limited installation conditions

Thin film: low energy efficiency, but thin and flexible, so mountable on many types of surfaces.

That 22% you’re quoting is for rigid rooftop panels. Thin film solar, like you would have to use on curved surfaces of a car, is nowhere near that efficient.

 

[JRP3]

Putting that much solar on a car will be hideously expensive since unlike rooftop panels the car is curved. Add to it the fact that it needs to stand up to hail and the elements.

You mean just like the pano roof?

It has been estimated that the solar installed on the Fisker Karma cost around $5000 and that's just in the roof. It only provides around 100 watts of power. I read the ROI is around 500 years and it adds at most around 1/2 a mile of range per day.

I wouldn't use anything done by Fisker as an example of what something might cost or how it would perform.

Adding it to the hood would be a problem since you don't want it to crack when hit by rocks and whatnot.

If you are encountering rocks and whatnot that could crack a solar panel those rocks would be denting your aluminum hood quite severely.

For the amount of money it would cost to add it to the car you could buy quite a few panels and microinverters.

And that helps the vampire drain when not plugged in how?

 

[brkaus]

Once the self parking/driving on private property is working... The car can realign itself to the sun through the day.

 

[MorrisonHiker]

Once the self parking/driving on private property is working... The car can realign itself to the sun through the day.

Perhaps the air suspension could be used to tilt the car towards the sun as well. :wink:

 

[aaronw]

Unless you're using the inefficient thin-film solar cells, normal solar cells are extremely brittle, unlike aluminum which will deform and return to its original shape (unless deformed too much). I've already had my windshield cracked by a rock and my replacement windshield required repair a year later (same drive to Reno). Replacing the hood would be far more expensive. The panoramic roof is far less likely to be damaged by rocks, but that also happens.

If you're frequently leaving your car unplugged for extended amounts of time then an EV is probably not the right car for you. The vampire drain has been reduced quite a bit and I'm sure there's plenty of room to further reduce it. If you're in an area that gets snow solar will be useless, especially since the batteries must be heated and solar will do little to help there, especially if covered by snow.

 

[Candleflame]

Regarding the effectiveness. My parents have got a few solar panels on their boat. One is 1m x 30cm (with some soft enclosure around it) and one of these panels produces about 180w when the sun shines. You could probably easily fit about 4 of those on the car roof, and maybe a few more on the car if its propery enclosed in the aluminium chassis. On the grand scheme of things thats not an aweful lot really...

One of those panels is about 200 euros or so.

 

[techmaven]

I think we should not talk about a solar panel option as actually charging the high voltage traction battery. That ends up being silly.

Instead, there is a very real problem with the load on the 12v battery. The BMS is running all the time. The infotainment stack with the cell stack is running, either some of time or all the time in order to communicate with Tesla and the smartphone apps. This amounts to about 40 watts. Given the relatively small 12v lead acid battery, this is a big drain and periodically, the car has to switch on the high voltage battery to charge the 12v battery. I think solar panel option would help this issue tremendously. Then "always connected" cell option + BMS might be say, 50 watts. That's easily doable. We already have a glass roof with the panoramic roof option - so the major expense of the glass is already done in that option. We just need about a 100-150 watt panel at STD which means it can realistically pull in 50 watts in all sorts of conditions.

 

[bxr140]

I think we should not talk about a solar panel option as actually charging the high voltage traction battery. That ends up being silly.

Silly depends on context. Current and near term technology certainly doesn't make sense, but with 1kw per square meter (more or less) of solar energy hitting the earth, at some point we'll end up with the ability to harvest several kWh a day through our cars. Especially as vehicle efficiencies increase, that could be enough to cover many peoples' daily commute.

 

[Discoducky]

Once the self parking/driving on private property is working... The car can realign itself to the sun through the day.

Hmm, that option has been removed from the site...

 

[roblab]

Interesting how this discussion never seems to go away. After years of rehashing, it always ends up: It won't work.

Any of you that want solar on your car, hey, go get a small panel at an RV shop and tape it to your roof (like they do on the Red Green Show) and wire it up. You'll figure it out pretty quick.

The reason you won't find one built that way by Tesla is because it's DUMB and Tesla doesn't do dumb.

 

[JRP3]

Tesla does do "dumb", like a car that will discharge itself into oblivion if left unplugged. A solar panel would prevent that. That's not dumb.