Honestly it seems like a no-brainer to me to put a solar panel on the roof of electric cars to increase their action radius, so I figured there’s probably one or more good reasons why they don’t.
Also, I acknowledge that a quick google could answer the question, but with the current state of google I don’t want to read AI bullshit. I want an actual answer, and I bet there will be some engineers eager to explain the issues.
Doesn’t provide enough power for the cost of the cells, plus having to clean and upkeep them. And the more material you cover them with (to protect them; solar cells are INCREDIBLY fragile), the less efficient they are. I was on a solar car team in college and the cells are so fragile that to clean them, we had to use new microfiber cloths every time. Any dust would scratch and ruin them (which made it quite tough when I drove across the outback in the thing). We kept our cells completely uncovered because we needed maximum efficiency - but even with a super light carbon fiber solar car that’s got very minimal tire contact patches, specialized tires from Bridgestone, and a very aerodynamic shape (plus no amenities like A/C), I think our car could sustain something like 10-15 km/h on a perfectly sunny day in the middle of the outback. It just doesn’t add enough on a huge, heavy EV
And more weight means less range.
On the other hand: most cars are not moved 23h a day. They just stand around.
A lightweight solar panel could be a worthwhile range extender in at least some climates.
On the other hand: most cars are not moved 23h a day. They just stand around.
It doesn’t take much shade to have a signifigant reduction in the output of a solar panel.
Unless you are parking in an open field with no trees or tall buildings around, your power generation will be signifigantly reduced.
Not that the amount of power generated by a panel the size of a car roof is all that much, even under ideal conditions.
Exactly. And what’s worth remembering is that solar cars tend to be something like 2X longer then normal cars, and cover the entire surface except for windshield with panels. No rear windshield, either.
On the other hand: most trips are made to the exact same place, why move solar panels around when you could just leave them in place (especially if the car isn’t moving for 23hr)?
I’ve seen some prototype solar panels that roll up like a carpet for easy storage. Keep it in the trunk, lay it out when you’re gonna be parked somewhere for a while.
Now THIS is podracing
Having solar cells uncovered by glass is baffling
Yeah, it’s certainly a good thing it doesn’t hail in the outback lmao
So a solar golf cart might be doable?
A 9v battery powered skateboard is viable if you pick the right combination of weight, speed, and distance. Doesn’t mean it’s going to change the world.
The Dutch have been working on this for ages : https://lightyear.one/
For range it doesn’t add much in most cases. But it also depends on how long between journeys you have. If you’re traveling in a van and you are going to be stationary for a few weeks at a time then it can start to make sense, maybe with an extra fold out.
The same could be asked with smartphones.
Why don’t smartphones include solar panels on the back side of the phone?
We buy solar phone chargers for use in the backyard. They work ok. It would take a long time to fully charge, but it will keep you from going empty.
Do you usually use your phone in the sun or leave it exposed to direct sunlight?
Well, it lays on tables a lot, with the backside facing up.
The first generation Hyundai Ioniq 5 had solar roof (at least some models).
The first gen ioniq 5 also had a very low payload capacity, with stories of families who couldn’t legally be in the car at the same time without being over the capacity.
The reason, I’m told, is that supporting the solar roof reduced the payload capacity a lot.
Also, solar cells on a car doesn’t make much sense like others have already said.
Look at the Fisker Ocean, it adds almost no range or energy, and leaves horrible and distracting shadows on the passengers. Youat as well ask why you can’t charge a car with a D battery.
Once upon a time Audi had solar panels on the roofs of their car and it could only generate enough power to run the cabin fan to try to cool the car down while you were parked.
To give you an idea of the sheer amount of power that an EV requires to move its bulk, look at the sizes of their batteries vs home battery packs. An EV has battery packs of around 100kWH and that can get you a few hundred miles range at most. Now compare that to the requirements of a home battery. The average use for an entire home is about 30kWH per day, and most home batteries only recommend 10-15kWH.
Looking at that you start to see the massive difference in power usage required. To charge a small home battery like that you usually need multiple panels (10+). They just don’t have the space and power generation to offset the sheer amount of power EVs require.
Solar panels on the roof and hood of a car are dubiously useful. This car has panels on the sides of the doors? Those are going to get but a fraction of the light the roof ones will. This just looks like someone tried to shove as many on as possible with zero thought into the efficacy of the idea.
So, this concept is too expensive :
(…) In February 2023, the company announced it would cease developing the vehicle, citing a failure to crowdsource sufficient funds.
Assumption:
Someone crams a 300 watt solar panel onto the roof of their EV and manages to integrate it into the charging system so that it’s pretty efficient to use that power.
Numbers:
One hour of good sunshine on the 300 watt panel = 300 watt-hours (Wh).
Average EV energy usage : 200Wh per kilometre these days. Maybe a little more, maybe a little less, depends on how and where you’re driving.
Result:
One hour of perfect sunshine hitting the roof of your car equals 1.5 kilometres of extra range, or you can drive your car in a steady-state fashion at a 3-5 kilometres per hour because an EV is more efficient than the average usage at lower speeds.
Conclusion:
Probably better off increasing the storage capacity of the battery as a full day’s sunshine will get you about 10 kilometres of range.
Wouldn’t it better to just build more solars to power the chargers? It scales independently.
Solar cells on a car have no real use. You would have to leave the car out in the sun for weeks to months to charge it up just once.
Seems worth offering as an option. If you can get 10-20 kms out of the solar panel in decent time it might be enough of an emergency precaution to give people who live outside of cities less reason to poopoo EVs
There’s two problems with this:
Panels are not free. They cost money to install, weight to move around, and prevent you from a mega-sunroof that most EVs have.
Second, if you think one inconvenient charge per month will make people outside of cities and disparage (for whom EV already offer the most advantages) change their opinion, I think you will be disappointed. Most of them formed their opinion by “but I don’t wanna!”, not by any logical thinking.
This is the exact type of gimmick/bullshit they can utilize to convince people to get over irrational fears. Because people are often irrational when making decisions.
But its also tied directly into the fear of running out of juice in the middle of no where. It not only offers but actually gives people comfort and security. Even its really not meant to actually be used regularily or ever really.
I know one mechanic who has both a Model S and Leaf. He HATES that his model S slowly drains the battery when not used and his leaf does not. And he can explain the difference both why and how. If a company just used that fact to sell their car over any car that also loses charge sitting unused they will absolutely have an advantage for people. Imagine parking your car for weeks and it always being as charged as you left it or more instead of sometimes having to worry if you have a dead car waiting for you because you realized after the fact that you left it with a low charge
I absolutely do think it will change enough minds. I work in the industry from the repair side. But also with people who use their vehicle to pay their wage. I know this can work towards removing that part of the equation because there is a TON of people who dont want EVs to replace ICE and they stoke every dumb fear people have. Having the option, however poorly it performs has always been a net postive as long as it does perform the way its supposed to
Good sales people try to understand what is preventing people from making good choices. Bad ones just lie to you.
Additional costs are exactly what people expect to pay extra for ask in think that’s really a moot point beyond getting the amount in the right ballpark.
I appreciate the long form reasoning, but I disagree. People I’ve met that don’t like EVs, they don’t like EVs first, look for a reason later. There is of course a tiny, minuscule minority that do more than 300 miles of driving a day and cannot spare 15 minutes to charge, but that is well under 0.1% of drivers.
Never said it was people who drive high kms a day that has these concerns.
Seems to me we arent disagreeing on reasoning but about different situations. Such is the way of not speaking face to face though.
If it helps im not just making shit up, i deliver (ive moved up and am low level.operations now) autoparts to repair shops and have heard these complaints for over 10 years.
Its actually quite fascinating how often people drop the concern im trying to discuss once they start using an ev, or personally know someone who has one and they get encouraged by their persons lack of concern about losing a charge.
I think i wouldnt pay extra for the solar panel version if it was a significant extra cost but Maybr if it wasnt too much. (15k for full.self driving which doesnt even transfer to a new owner put the brakes on the failing enthudsiasm i had with tesla when model s was new)
More like 5-10km, and then only on a sunny day in the sun, which would make the car uninhabitable due to the heat.
Better put a few square meters on the roof and use those instead of the 2-3m² you can place on a car at suboptimal angles and with the requirement to park in the baking sun.
Thanks for posting the question! Whole point of the community.
I think we’ll see more of this in the future as they continue to make progress on inexpensive “solar paints” and the like. It’s not a bad idea, it’s just that the tech level doesn’t show much bang for the buck…yet.
This guy heard you:
While that might not be economically feasible, I’ve always wondered why plug-in electrics couldn’t send power back into the grid. No solar? Send energy onto the grid during the day from the car and recharge during the off-hours at night. Solar? Recharge during the day and send energy onto the grid at night. Just make sure to set a minimum charge that will get you to a charging station.
IIRC some car batteries can be used that way, but it wears out the battery.
For LFP batteries it’s irrelevant. They have a 3000 cycles to 80% cap, some of the new ones have 6000. That’s 10 or 20 years assuming full discharges an recharges everyday.
Or in terms of lifespan, assuming a realistic 400km range (250 miles), it’s between 1.2M and 2.4M km before the range reduces to 80% (750k and 1.5M miles). The car will be completely Theseus-ed at the point.
Some do, but to do this, the point of entry to the grid needs to be set up in such a way as to support this, with an automatic transfer switch for when the grid disconnects, and a meter that reads energy use as both incoming and outgoing, rather than the default of all incoming.
Source: am electrician who has installed batteries on peoples houses
on the roof doesn’t make much sense. What I did see the CSIRO testing was a portable solar array that you could roll up and store in the boot. IIRC they drove a Tesla across a large swath of Australia stopping and only charing on the portable array as needed
I had similar ideas using a VAWT, mount it on a speaker tripod, set it up to catch the evening and morning turn over. Maybe catch a trickle charge.
