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.
I don’t remember what car it was but an ex’s car had this. It was only really used for keeping the car from getting way too hot while it was off in the summer.
If the solar panels could be efficient enough to run the air conditioning, I’m sold lol
My Prius has this. It literally just runs a small fan in the summer to keep the interior/batteries cool.
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
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.
Ot 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 not 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
So a solar golf cart might be doable?
And more weight means less range.
Having solar cells uncovered by glass is baffling
TLDR solar panels have a lot of inefficiencies, which makes them more of a detriment to mounting on standard commuter cars when you take into account the effects of the added weight.
What I have seen previously is that the amount of energy you get from the solar cells that you could fit on the top of the car is really small compared to what it takes to charge the battery.
Since there is minimal benefit, and it’s costly to include them and wire them to the battery, it hasn’t been viewed as worthwhile.
For comparison, my rooftop solar array, with around 16 full-sized panels (~6kwp) produces just under 2 miles per hour in my electric car (around 3.3kwh/mi). Or in real life, takes about 2 fully sunny days to produce the power to charge the car.
What kind of ev are you driving? That’s insanely high energy usage.
My EV gets about 6km per kwh (around 4 miles)
You get 4 miles per kwh and they get 3.3 and you call that insanely high? The 2.5-4 mile to kwh is really standard for EVs. I don’t think the 3.3 is outside of the norm at all.
Fish reversed the numbers. It should have been miles per kWh
I don’t know anything about EV efficiency, but the rates are inverse, so they are drastically different.
Fish gets 3.3kwh/mile
Peacock gets 4 miles/kwh or 0.25kwh/mile
Oh I see that error now. I guess I just assumed from context his 6kwh panels generated 2 miles per hour. I get the confusion though
I’m still a little confused, wouldn’t 6kwh provide roughly 12 to 24 miles of driving range?
They mentioned their car uses 3.3 kwh per mile. With their solar setup they can generate around 6hwh per hour. Meaning they can generate roughly 2 miles every hour of sunlight.
Yeah this is what I’ve heard as well - aging wheels goes into it a bit in this review of a concept car, kinda neat - it has pedals like a bicycle but the energy they add is a tiny fraction of what the thing needs to move.
it has pedals like a bicycle
Are you taking about the Aptera from the video you linked?
If so, the Aptera doesn’t have pedals like a bicycle. It’s a fully electric vehicle (or it will be if it reaches production).
Ah crap, you’re right - that’s another video of his, apologies
Spot on.
Rough summary of when it is energy and effort efficient: https://xkcd.com/1924/
A few of them have. The core issue is it doesn’t add much range, while at the same time adding more cost, weight, and complexity. On a sunny summer day you can expect to get single digit kilometers added to the range, while on a cloudy winter day you won’t get even a full kilometer added.
They do make some sense on hybrids, as they are lighter so the range increase is a bit more and people are less likely to charge a hybrid. But, they still suffer from not adding much range, while adding cost, weight, and complexity.
Bear in mind also that the extra weight and possibly aerodynamic compromises actually reduce range. In some cases, particularly at night, in poor weather, and at high speed, the panels would be a net negative.
They would only be useful if your car sat around in the sun for long periods without access to a charger.
such as parked at work or in a summer traffic jam?
Parked at work it will probably have a building nearby that creates a shadow. In a traffic jam, assuming perfect sun conditions and no shade, a 100W panel will generate around about 500m (or yards) of range per hour. Meanwhile the AC will use about 700W to 1kW of power to prevent your face from melting.
Some tests on YouTube report a realistic addition of 1 mile per day using the car in a typical commute.
Depending on the car and the temperature, AC Is simply not an option (same for heat) in a traffic jam. I drove a 2019 Nissan Leaf (with 12/12 battery bars and normally 80-140 miles in range, depending on the season)for my 19 mile commute for a while, and had an awful time during subzero temperatures (~-20 Celsius) once. I went from fully charged on the work chargers to considering breaking out my reflective emergency blanket in three hour stop-and-go traffic so as not to kill my battery before home. I stopped to charge and it took much longer than usual, to the point that I just gave up and used my hand warmers and hoped on the way home.
I don’t blame the car for that, I was unprepared for the predictable consequences of cold temperatures on electric cars, but it was still super unpleasant.
Leafs have battery packs with no active heating or cooling, which significantly impacts their performance in bad weather and when fast charging. Coupled with very small packs in the early models, and you have a recipe for a bad experience.
Modern EVs such as Teslas have a high power consumption, much higher than some PV panels on the roof could deliver. Thus, it would only increase the weight of the car while not significantly increasing their range.
In addition to weight, there’s cost. They would have to be integrated into the design, not just normal, flat solar panels, so there’s a significant cost increase. It’s no problem on a delivery van, but anything curvy is probably prohibitively expensive to develop and produce.
It would be cool if they were built into the highway and could charge your car as you drive over it. That might make toll roads almost worth it.
The Fisker Ocean has solar panels on its roof. It can add 4 or 5 miles a day if fully exposed to the sun.
Not enough to matter. It’s a gimmick.
If you don’t have an EV, you may think that EV owners are worried about range, and they’d welcome any increase. I have not found this to be true.
It’s more like having a car that starts every day with a full tank. You’re never going to burn through that in a single day. Pretty soon you don’t care about range, efficiency, or pay much attention to the battery meter. It only matters if you’re on a road trip, which for me is a couple times a year.
I would not want to give up a nice full-roof sunroof for a few extra miles a day.
Right. Unless you live in US and have relatives you regularly visit in a different city in the same state only 400km away.
I mean I still don’t care about solar panels on my roof and I’m much happier with a moon roof on my PHEV. Nearly 80km of electric range means I’m driving an electric car 99% of the time and have convenience of 5 minute fill ups when I go further.
The newest revision of the prius has an option for rooftop solar. The break even point is relatively long, in the 5-8 year time frame iirc. The energy generation isn’t massive; at 185w it won’t substantially extend the range something like 5 miles per day.
For an extra miles a day… if you park in the full sun all day every day. Garage? 0. Driveway? Probably shadow half a day.
if i park in the shade, and therefore don’t have to turn on the ac as soon as I get in, I think that would be about the same, savings wise.
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.
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
Because it barely matters. Like putting an extra AA battery in the glove box.
Well now the question is why they don’t put an extra AA battery in the glove box.
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.
I think they should put windmills on the roof. If you’re going down the freeway that would charge the battery real quick! /s
Obligatory windmills do not work that way, also that’s exactly how an alternator works.
But… That’s exactly how a windmill works.
Windmills don’t generate electrical energy. For that you need a wind turbine.
Windmills don’t generate electrical energy
What if you used them to grind pizeoelectric materials like quartz? 😌
Nah physics is fake news
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.
The amount of power you could pull from a single square metre of solar on the roof wouldn’t increase your range meaningfully.
What it would do, is that you could possibly keep your starter-battery from going dead-flat if you left your car alone for a 1/2 month, in the summer ( snow would cover it, obviously ), & since bringing a lead-acid battery to dead-flat permanently-damages it, this would prevent costly problems for the car-owners.
( this happened to a friend with a Prius: had to replace the battery, and the damned thing was inside the rear wheel-well??? in a little compartment.
Origami-engineering’s … simultaneously incredible & stupidly-frustrating )
I’ve held for years that they should be doing it to keep the starter-battery trickle-charging, but … why make the customers have fewer costly/frustrating problems?
