Speak EV - Electric Car Forums banner

1 - 20 of 28 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi,

Does anyone know a company that installs solar panels on electric cars? The solar panels should charge the battery (obviously). I've seen a DIY guy on YouTube do this, but I'm wondering if anyone does it professionally. I think the guy on YT planned on starting a company to do this.


Thanks,
Ben
 

·
Registered
Joined
·
1,087 Posts
It really isn't worth it for the power you'd get from a practical sized panel. And it would be very hard to get a panel contoured to match the car. You could stick a flat panel on a roofrack but the aerodynamic losses would most likely offset any power it produced
 

·
Registered
Joined
·
219 Posts
Sorry, I don't know the answer to the question. For aftermarket retrofit, it seems very impactical to me. I think it would be very hard to fit to the car and would cost a fortune or a fair amount of time and expertise to do it well.

I do like the idea of solar panels on electric cars though. I just think it needs to be built into the car in the first place for economies and scale and design, and marketed honestly, i.e. it will only realistically provide a small proportion of the car's energy unless you use it very occassionally.

I see that Sono Motors "up to" 34 kilometres refers to a fully sun day in June.
They estimate 3km from the solar panel for a cloudy day in December.

One thing that would be nice about a solar panel on a car is that if you ever ran out of juice and couldn't make it back to your house you could just park it and come back and get it a while later. Having that as a backup option might actually be a little extra peace of mind. In some cases, it would make more sense to do that than get it towed.

I wonder how much it would cost to build a solar panel into a car if done at OEM level with economies of scale. I think the actual solar cells are going to be worth a couple of hundred dollars, and then you have got to factor in other components in the system and what is means to the engineering process. Maybe $300-$1000 per car?

However, the car does need to be parked in the sun most of the time it's parked for it to be worth it. The energy gained while driving will never pay off the cost of the panel, and the avoided grid electricity used when driving may not even cover the carbon emissions in the panel's construction.

And so it only works if both you and others using the car including passengers are happy to leave it parked in the sun and come back to a hot car. If it's mostly going to be parked in an underground car park or a garage it's not going to work.
 

·
Registered
Joined
·
4,095 Posts
As above.

The area available on a typical car is around 4m^2 which would give at most 800W on a sunny day at around 80 volts DC. The minimum charge that most EVs will take is 1.4kW and that is normally AC at 110 volts. If you invert the DC to give the voltage needed then you'll probably not get sufficient power to charge directly. You could add an intermediate battery to store the energy at a slower rate and then transfer it in bursts at a higher rate but the trip losses are getting very significant, although there are various firms that do this with adapted solar lighting trailers in your country.

EV Station - Mobile EV Charger

131659
 

·
Registered
Joined
·
1,533 Posts
As per other comments above, only Sion have a solution in the making and nearly the whole car is Covered in solar cells. As for retrofitting solar to current cars, it’s only really practical to charge the 12V battery and there are plenty of reasons that this should be mandatory on all EV’s. Endless threads about low volts on the 12V battery pre and post Covid19.
 
  • Like
Reactions: Neilew

·
Premium Member
Joined
·
3,891 Posts
I can see the sense in sticking some panels on the roof of your narrow boat to keep a 12v battery bank charged, but for a car and its energy needs it seems pointless.

Besides, then we’d get threads on here saying they’d left their car parked outside all week and were worried it was going to charge to 117%, and will the battery melt or something...
 

·
Registered
2018 e-Golf
Joined
·
704 Posts
There was a post of someone doing this on the "VW egolf owners group uk" facebook group with a picture of a flexable panel applied to the roof of an egolf. That was back in July 2019 and apparently he was still sorting the software side of it. Heard nothing since
 

·
Registered
Joined
·
474 Posts
I'm all in favour of charging cars on solar energy. The best way of doing this is to put the solar panels on the ground where they won't need to be transported, can be placed optimally at all times to capture sunlight and to allow multiple cars to use it as a shared resource. Panels fitted to your car will be heavy to lug around, not optimally placed most of the time and will spend much of their time doing nothing.
 

·
Registered
Joined
·
137 Posts
I guess its basically the same company as Scion, but Toyota offered solar panels on their first gen prius and then on their later plugin prius.

It worked like above charging a different battery used for consumers within the car rather than the traction battery. I guess it doesnt matter which battery it charges as its all the same pot anyways if the AC and stereo are running as the car is driving it will be the traction battery powering the DC/DC converter to topup the 12v. It was however a few thousand for it the last time i looked.
 

·
Registered
MG ZS EV Exclusive
Joined
·
343 Posts
you will never get enough from car-mounted solar panels to make any difference to the traction battery's state of charge. At best it will just keep the 12v battery charged.
 

·
Registered
Joined
·
156 Posts
As others have stated, PV panels don't produce enough power to worry about when it comes to charging an EV. Scion had them on their prototype, but they may never mass-produce a car. The cost:gain ratio is also against the idea. Forget it until a super-efficient PV panel is available. This may never happen...
 

·
Registered
Joined
·
3,763 Posts
As per other comments above, only Sion have a solution in the making and nearly the whole car is Covered in solar cells. As for retrofitting solar to current cars, it’s only really practical to charge the 12V battery and there are plenty of reasons that this should be mandatory on all EV’s. Endless threads about low volts on the 12V battery pre and post Covid19.
Would that also be mandated for cars sold in northern climates where there is hardly any solar generation for 5 months of the year?
 

·
Registered
Joined
·
436 Posts
Edited
 

·
Registered
Joined
·
3,483 Posts
There's a lot to be said for something like a solar-panel powered fan to circulate cool air through the car when it's sitting baking in the sun. People will pay over-the-top for luxury, and if a lovely cool car to get into after a scorching day out isn't pure luxury, then I don't know what is! If there's enough power to operate something like a Peltier-effect cooler, it might be worth a try.
 

·
Registered
Joined
·
483 Posts
Audi trialled it on a couple of their cars - having solar panels on the roof to power the AC so that the car stayed cool.

To make sure you could get a meaningful charge on an average day, I once calculated that you'd need panels the size of 2 tennis courts. The technology may have moved on a bit since...
 

·
Registered
Joined
·
4 Posts
Discussion Starter #18
I live in an apartment without a charging station. I was thinking I could leave it on top of the parking garage to charge somewhat, and reduce the frequency of trips to my local public charging station.

Why do you want it Ben ? Because you wont be charging your car with it enough to make a difference.
 

·
Registered
Joined
·
3,483 Posts
Sure, lots of clever stuff can be done. There's a company in USA converting VW campervans, they have I think 3 sets of panels stacked like 3 trays on top of each other, mounted above the roof. When you park up these slide out of each side & give you a really useful solar capture area. But all folding/collapsing mechanisms on cars take up space, add weight & complexity, so you have to question if it's worth it. Think convertible cars, anything folding out to capture the sun is going to have to be robust enough to withstand a sudden mistral arriving, etc etc. Easier just to have a bigger battery to begin with, and put the panels somewhere safe & sensible, like roof of house. Where they spring into efficient action the instant there's any sun, no folding gadgetry needed. Even with these the ROI is marginal; panels on a car cannot be used every time the sun's out, so ROI has to be really doubtful.
 
1 - 20 of 28 Posts
Top