People seem to do the math and get maybe 5-10 miles of range per day. I’d say that actually quite useful. Especially if you only drive around town or leave your car for days at a time.
Or imagine running out of battery in the middle of nowhere with no phone reception. Just wait a day and keep driving to a better spot. That’s really useful.
Finally this ignores the idea of having panels that fold out when you park. You could easily 4x your solar collecting area and get some real range.
Does it often happen that the typical driver of a car is somewhere in the middle of nowhere, with no cell reception? If not, it seems of limited usefulness.
Bad value versus what? If you invest the same money in a stationary PV grid at home, it is a much better value, that is the point of the article. As I have a PV grid at home I mostly agree with that.
From an economic and environmental perspective home PV make sense (but the investment takes many years to recover), on cars not at this point, maybe in the future.
The article describes options less than 1 KW, at home you put 5-20KW, it's a very different kind of beast.
Yes, and people don't understand that EVs actually use quite a lot of power relative to a freestanding home.
If your home uses gas/oil for heat & hot water, you might only use, say 20kWh/day in winter and 35kWh/day in summer. This matches pretty well with the amount of solar generation you can put on your roof! The cool thing too is that you get more sun in summer, when it is hotter.. and you use more electricity because of the AC.. so it matches pretty well!
Now that same 20KwH in winter is enough to fill 20-30% of your battery of your EV to drive 60-80mi. Your little car roof will generate minuscule amounts of power by comparison to your entire homes roof, while also being at the wrong angle, sometimes parked indoors or in shade, or in motion & not charging during daylight hours.
You've just added a motor, a wear&tear item, another $1000 in cost to the panels by adding the folding mechanism. Don't forget some sensors to ensure the car can't be put into drive while panels are folded out.
How much charging time gets consumed back by the panel fold in/out movement?
Does the car now need an interface to allow the user to select when to fold out (long planned parking only?).
Yeah, 5 miles a day would cover 99% of my driving lately.
When the Aptera announcement came out, I analyzed my fuel receipts, and concluded that I would plug the car in 2-3x a year (occasionally I find myself in Chicago or other day-trips), but the rest of the time solar would more than cover my usage. And that's assuming some hefty derating for latitude, cloudy weather, etc. I just don't drive that much, but when I do, it's places and times that aren't well served by transit so I very much need a car.
If I go back to working at the office and solar only covers a portion of my driving, that would still likely mean plugging in once a month instead of once a week without the solar, which is still pretty cool.
I think this article is "it's not a 100% solution so therefore it's a 0% solution", which is a pretty tired tactic at this point.
Agreed, the vast majority of US population travels more than 5 miles/day.
Once we are down to the subset like the person I responded to who claims to need a car AND to only travel 5mi/day or less.. maybe! Or I mean, isn't this why we have uber?
If one was to drive only 5mi/day at 30mph, that means the car is not in use 99.31% of the time. Only driven 1,825 miles/year. What percentage of Americans drive less than 2,000mi/year? The average is closer to 15,000mi/year.
Dealing with costs&time for car, insurance, regular maintenance, registration, emissions inspections, etc... for something you don't really use? A lot of these are fairly fixed costs regardless of mileage. Probably end up spending like $3/mile TCO at such low mileage rates.
The unfortunate reality is that 2.5 miles each way is a 50 minute commute walking and 7 minutes driving so in practice you get about 12 days worth of waking hours back a year before everything else you use it for.
And it’s more comfortable — you can do it when you’re tired, sore, or sick, in the rain snow, and heat.
There is nothing that is going to usurp personal vehicles anywhere but the very densest cities without changes that are infeasibly expensive and trample on people’s property rights. The new hotness is walkable areas surrounded by parking so you only need the car when you leave.
Because the math doesn't make sense. The added weight, build cost, and complexity make it less value than plugging in.
Your "running out of battery in the middle of nowhere" scenario doesn't make sense. If you're that close to help you can walk there in less time than it'd take to charge the car.
This stranded scenario is a such solution in search of a problem. The charge rate is slower than walking speed, and 5-10 miles is an easy walk (likely preferable to spending whole day roasting in a car without A/C).
Besides, EVs don't suddenly run out of battery like you imagine. Batteries display state of charge very accurately, so you'd know way ahead of time if you shouldn't be heading towards middle-of-nowhere. But even then, EVs don't run out of battery suddenly, but gradually lose power and get slower. To get stranded, you'd have to be a fool ignoring all predictions, satnav, and then stubbornly drive slower and slower for 20+ miles while all the warnings are beeping at you.
RVs are by their nature stationary for long periods of time, and the RV are using the solar to power appliances & creature comforts inside.. which is rounding error next to moving a multi-ton vehicle.
What is your point? Article says that it "makes no sense", I provided two counter examples.
ICE cars also have batteries, if that gets flat, car is not going anywhere. Solar panels can be quite essential, if vehicle is parked for extended periods. It is not just some rounding error!
Again! Trickle charge from solar panel extends battery life of internal (part of ICE) lead battery. This battery slowly discharges from internal resistance, other electronics (car alarm), GPS spyware...
That means less batteries, less lead in nature, more green stuff, happy Gaia...
And even EVs like Tesla has slow discharge. It makes sense to put small solar panels on top, so they can do firmware updates.
It makes sense on EV for the same reason as ICE. There are any number of devices in a car that are always sucking down some small amount of power. Alarm/security/camera systems for example. Clocks and chips that store settings. If you're gone for a week you'd rather not have your battery go down.
There’s a device for that called the Norelco Genius 2D. It is suitable for permanent installation in your car on the premise you have access to an outlet. It costs $50.
If you have street parking only it is questionable whether you will be able to leave a car a whole week without incurring the wrath or a municipal agency. If you have parking lot parking only in an outside lot at an apartment complex of some sort, you might prefer a panel, though I more that you can get a kind that you leave on the dashboard that plugs into the lighter socket for a similar price —without the convenience of an integrated form factor admittedly but still.
RV and sailing boats have a relatively large area that can be used for panels. Small installations (less than a couple of kW) have a low efficiency, the inverter and storage losses benefit of scale are lost.
We use solar panels to run the microwave, not move an 11,000 lb. vehicle. As I said in another comment on this very page, the math isn’t hard. Most HN readers can probably do the calculations in their head. And yet half the comments are evidence that some folks can’t be bothered to do even that simple exercise.
It's astonishing really the confident stubbornness.
There's a reason that every company that has tried this has gone bankrupt or soon will.
The path to mass market EVs is having good charging accessibility and low prices. Adding more cost and telling owners to remember to park in the sun is not it.
> Solar panels make great sense on ICE vehicles. Trickle charge from small solar panel may preserve internal battery much better.
Hmm. I just bought a new 36 month battery for $110. Never in the last three years did I have any issues with the battery not being "preserved." $2000 of solar for no measurable impact on the usability of my ICE? This doesn't make sense. $2000 buys me 50 years worth of 36 month batteries. The only time you would need trickle charge is if the car is parked for long periods of time with no plug-in available for trickle charging. That's a niche need. Plug-in trickle charge for the life of the car would cost a lot less than $2000.
RV? When parked with no plug-in power available, sure it would be nice to have some electricity without having to run the motor. Other than that, the tiny bit of solar you could put on the roof is completely insignificant with respect to the power needed to move the extremely heavy RV.
Last nearly two years I have used my ICE in worst possible way. Nearly completely short city driving from cold start during winter included. Never has it failed to start due to battery being low.
For RV and boats I think solar panels make most sense. But it is not for moving the vehicle, but to charge a alternate battery that is mainly used for electronics, tv, computers and maybe, maybe a fridge...
This article is thin on content and wrong on many many points.
1° the Lightyear Zero is actually in production. There is no reason to think the cars built won't be sold soon...
2° the lightyear 0 has a sophisticated series of controllers for its solar cell that can activate solar cells independantly, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade.
3° dust doesn't reduce solar output that much. Washing the panels once a year is generally enough, and most people wash their cars more often than that.
I love back-of-envelope calculations to check for lies, but they shouldn't preclude making your minimal homework first...
> sophisticated series of controllers for its solar cell that can activate solar cells independently, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade
Aka just putting a single bypass diode on every cell, it's not complicated.
Aptera is also close to production. Several other, manufacturers are adding solar to their vehicles. Also, there are a few electrical campers with some solar panels. So, basically these things are coming to market.
And why not, it makes a lot of sense. Most cars don't drive most of the time. And if they are catching any light, you basically top up the battery a little bit for free.
Or put differently, that's energy you don't have to pay for. Yes, it adds some cost. And it saves you money. Kind of balances things out pretty quickly. And it adds some convenience for day to day use where you add enough power that you don't have to go to a charger so often. Especially for short commutes, this makes a lot of sense.
Dust is not a big deal. Indeed nothing a good old car wash can deal with. Or a bit of rain. Panel degradation happens very slowly otherwise. I don't think that's a huge concern.
Aptera is far more likely to go out of business than to be the next Tesla.
Right now in terms of likely to survive five years in EV land, you can rank Tesla>Rivian>Lucid>Fisker>Aptera>Lightyear .. and there's probably some other clowns I am forgetting. Like Lordstown, Nikola, Canoo, Faraday, Bollinger and Vinfast!
Vinfast has a higher chance of being alive in 5 years than Aptera. At least they've made a bunch of (pretty bad) cars.
Of the above list, if 3 of them beyond Tesla are still around on the other side of whatever recession is pending, and actually shipping cars in the 10k/year++ range, I'd be shocked.
Rivian is dropping money like there is no tomorrow and they survive because they razed unimaginable amounts of money.
Tesla isn't even in that league anymore, they are more profitable then all other car companies (outside of Toyota). Its more likely some of those will bust (or merge) before Tesla will go bust.
Take it as a free win - and although I'm not dyslexic autocorrect works to portray me in a similar light, which of course I usually only notice after the edit window has closed.
I have a reservation on a Canoo. It’s the most interesting EV out there, I hope the Army, Walmart, and NASA contracts keep them afloat long enough to launch the lifestyle vehicle.
Consider carefully if you are rich enough to consider it like an "extra car", such that even if they survive due to those contracts.. you are willing to be a guineau pig for a car which may not have a service center within 200mi of your home for 2+ years, go out of business before your warranty expires, etc.
Good ideas always start out small. Pennies are cheap and some of these ideas actually work out.
That happens. But you see a lot of good ideas being copied. I think there are already several bigger manufactures that have announced solar panels as an option. A bit gimmicky for some of them of course. But its an easy up-sell and they love up-selling.
Solar panels are widely used, widely understood to work, and the economics are trending to the point that you can slap them on just about everything. Like cars. Kind of obvious when you put it like that. Which is why that is a thing that is starting to happen in the car world right now. The couple of square meters of roof and hood provide a tempting target. You get maybe 2-3 kwh out of that on a nice day. That's 10-15 miles in an efficient EV. For most commuters, that would be very tempting and it might even be close to all they need on a daily basis. Meaning they'd be able to stretch their battery over weeks or months of use in between charging. Add grazing some free kwh at the supermarket or other places and it's perfect for people without the ability to charge at home.
> you basically top up the battery a little bit for free.
This is undeniably true. The catch is how very little that "little bit" actually is.
I have both a boat and a travel trailer powered with solar (I occasionally plug in the travel trailer but the boat is 100% solar-only). And I've been planning on adding solar to a truck camper. So I'm a big believer in power independence through solar and I'm fairly familiar with the pros (free electricity off the grid) and cons (so very little power). For my use cases it just about works, by being very frugal with consumption. But these are use cases where the typical consumption is in the tens of watts.
An EV uses tens of kilowatts to move itself. Three orders of magnitude more. Trying to run that off its own rooftop solar is akin to pouring a cup of water into Lake Mead to bring up the water level.
Bad news - LY0 is already out of production, after an astounding production rate of 1 car per week. This just is a niche of a niche of a niche idea, high cost, low return.
Wiki:
he company announced in December 2022 that production had begun, at a rate of one car per week. Availability is currently limited to customers in the EU, Switzerland, Norway and the UK.[4] However, in January 2023 it announced that production of Lightyear 0 has been suspended to redirect their efforts towards production of Lightyear 2
Following to source article:
Helmond based Atlas Technologies which is responsible for production of the Lightyear 0 solar powered car, was declared bankrupt on Thursday, with the loss of 620 jobs. Parent company Lightyear had asked for court protection from creditors for the unit earlier this week, after announcing that production of the 0 model would stop.
Read more at DutchNews.nl:
Their design is based on a hyper efficient car, with a smaller, and thus cheaper battery. The solar panel is a small benefit, but would overall provide the car with more range per kg and $.
But to become affordable it needs major investments for reaching mass production, which nobody wants to do.
They still have the holding that owns the IP, so I suspect they will try to sell parts of their design to other car makers. Especially their in-wheel motors are very efficient.
I think a lot of these startups would have been better served as trying to be specialist OEMs for the one or two things they really innovated on and not tried to make a whole car.
Imagine if they were selling the old school car makers their highly efficient motors being built out of a single factory with no support network or retail stores needed. Instead of trying to take on the behemoths in an extremely low margin business.
I think the EV startup and SPAC IPO craze is really the final blow out top of the ZIRP bubble.
Look at mobileye for example. Instead of trying to mine gold, sell shovels.
The problem with that is, they can't raise money on that and the OEMs take 5-10 years before adopting new tech. That is why they mostly buy from established people like Borg. Being a small tech company that gets bought up into on of the large suppliers like Borg is a possible path but not all that likely.
I think in a traditional market, "hey we have this great tech we'd like to raise capital to operate as a B2B biz" would probably be fine.
In the crazy tech/EV/ZIRP VC-funded bubble, especially the final SPAC-it-rubes IPO cash-out phase... everyone was incentivized to raise way too much money as long as they pretended they'd be able to target and user market of billions. Sort of mutually agreed delusion.
I don't think in-wheel motors actually make that much sense. There is a reason almost nobody is perusing it. Its mostly pushed by start-ups who want to have some 'unique selling' points.
Their IP wont be worth all that much.
Honestly, it was pretty clear from the beginning they wouldn't make it. Starting a car company is insanely difficult. And they arrived right in the Wild West of free money and EV scams with a car that would be incredibly hard and incredibly expensive produce.
Without some absurd raises in money like Rivian or Lucid (Saudi money) you are simply not gone do it.
Yes.
This pops up on EV forums/reddit regularly "hey why don't we just put the solar panels on the car". It's a bearish indicator when any EV startup pumps a new prototype where this is a key feature.
Short version: adds weight and maybe $2000 manufacturing cost to the car. Best case current tech it maybe adds $50/year of electricity to your car, requiring you to park outdoors, in good FULL sun, in parts of the world that get a lot of sun-hours-per-year. Further solar roof of a car is not at the idea angle that a home roof is.
Remember while you are parking your car in said parking spots you are also baking the insides so in weather above say 55F, it will get quite hot and probably need to turn on the HVAC systems to cool the cabin and/or battery periodically.. wiping out some of your solar charging gains.
Aesthetically, tt replaces the lovely glass roof many EVs have and so makes the experience worse.
If you have a garage charger or charger at work, this is rounding error and irrelevant.
If you don't and need to fast charge regularly, the fact that your car adds LESS THAN 1kWh/day from solar charging will save you.. 24 seconds of fast charging, per day of solar charging.. lol.
If the extra cost is $2000 and a solar equipped car will recoup at best $50/year as OP stated then $2000/$50/year is 40 years to best case time recoup the cost of the panels.
Also you don't seem to be aware of this but $2000 is a lot of money to some people -- It's more than they spend on personal transportation.
* The attitude "$2000 is a blip" is why electric cars are expensive.
* People without home electricity (or who live in dense urban areas without parking) are not the market for the car at this time. There is no reason to make everyone else suffer out of theoretical concern for people who don't even own cars now.
$2000 of electricity would take these cars 40 years to generate.
Their warranty will be up in 4 years, and they will be in the scrap yard by 15 years, at best.
Two grand in electricity from a couple square meters of panel will take an incredibly long time. Like an idiotically long time. This is a scam marketing ploy and nothing more.
Even level 1 charging off an extension cord on 110V charges 4x faster than these solar panel ideas would, adds no weight, works in any light conditions.. therefore overnight, and works with the included wall adapter all EVs come with.
$2k on a target $35k mass market EV is not insignificant.
I still stand by the idea that the Venn diagram overlap of "people who can't charge in their own home or work, even on L1" and "people who live somewhere rural/suburban enough to have completely open to the sun parking" is quite small.
L2 charging at a the grocery for 30-45min while you shop will get you as much charge as these solar roof pipe dreams would get you in an entire work week parked in a sunny field of dreams.
They say you get 2.5 miles a day or so in full sun. Lots of people drive only a few miles a day. I don't know if it actually matters, but for marketing purposes the ability to drive without the grid might be a good promo, especially when they can probably still bring the costs down a lot.
Hard to imagine a blackout so long that this would make a difference, that still involved having places to go inside the city, but in theory it could be useful.
Plus it's not from fossil fuel, which you probably care about if you bought an EV.
$2000 is a blip in the price of a car and will be recouped.
Probably won’t be recouped while you own it. It’ll be many years down the road. TFA covered this, perhaps a rereading is in order. Because what I’m hearing is “every little bit helps”, when in fact that’s not practically true.
The parent comment had good analysis. Your “short version” is wrong.
> $2000 is a blip in the price of a car and will be recouped.
If a $2000 price increase saves $50/year (approximate numbers) then it would take 40 years to pay back. But solar panels degrade over timeframes that long.
It also introduces complexity, so the average cost of ownership goes up as owners must repair broken panels, deal with water intrusion from a solar panel roof having more failure points than a solid roof, pay more expensive collision repair costs and so on. The mere existence of a solar roof would increase cost of ownership significantly.
Solar panels to charge EVs just doesn’t make engineering sense.
I can make $73/yr from $2k invested in 30-year Treasuries. The $50/yr from solar panels will literally never pay off against a risk-free, weight-free, maintenance-free, depreciation-free, liquid investment that’s 50% better financially.
I don't bring a $200 solar panel camping with me because I think it will save on my monthly electricity bill compared to getting those joules from the household outlet. I bring it with me because the household outlet is not available at my camp site. Similarly, in this case, I think "saving $50/year" is the wrong comparison. Its value comes from adding charge to the battery in locations where you probably don't have the option to pay the meter price.
It would make more sense to sell an optional add-on that's just a foldable set of panels that fits perfectly in the boot or frunk, one that you can then extend to way beyond the car's surface area, align to the right angle and plug in. They even make those light flexible ones now.
The main use case for this would be something like driving an EV across a desert or some backcountry well outside civilization I guess, otherwise it's probably easier to just find an electric socket somewhere.
It’s such an impractical option, starting with incredibly long charge times, that even for backcountry there would be better and more reliable options. For one, it won’t work in the woods because no sun. So the market consists of those crossing a remote desert. Those six people won’t even cover the cost of tooling.
I mean, the math isn’t hard. 200W out of a panel (at best), multiple by 5 hours to get a kilowatt hour. How many of those do you need to get back to civilization? Our Leaf gets 4 miles per kWh. The hypothetical desert overland vehicle probably gets half that.
You’re better off bring extra water and walking back for help if it comes to it.
Where are you getting that 200W from when cheap 450W solar panels are common?
Assuming say 60% of a 2m * 4m vehicle + some side panels @ 22% efficiency. You might get 6 hours * 220w/m2 * 2 * 4 * 60% = 6.3kWh that’s 25 miles at highway speeds and a fair bit more when your doing the equivalent of hypermiling.
I don’t see anyone trying to overland an EV but people do occasionally mess up and run out of gas on roads in the middle of nowhere.
It is my estimate of what will fit on a passenger car. I could only squeeze 410W on the roof of a 26’ RV. I doubt your 450W panel is going to fit even on something like a Land Cruiser.
And “side panels”? Ignoring the impracticality and inefficiency, no one with taste will be driving that. :-)
Besides, if you run out of juice, and if AAA will come get me in the Yukon 180 miles from Whitehorse (flat tire on the bike I couldn't fix), meaning 180 miles from anywhere, then they'll come charge your car anywhere in Wyoming. A AAA card is lot cheaper and more practical silly solar panels.
That must have looked tiny on your RV. I know people with a 3kw system (edit: 2940W) on a 28’ RV and they had an AC unit blocking some space. Now they don’t actually see that much power because the roof is a flat surface, but it’s enough he never carried through installing solar on the side panels like the initial plan was.
Of note, flexible panels are easy to install but have worse power output per square meter.
Toyota offered a solar roof option on the Prius for a short time. The intent was to provide power to run the AC for a car that wasn’t parked in the shade. I’ve worked at several offices where there was zero/limited covered parking and I would have grabbed this option for my Prius if it had been available.
It tells us that in the last 10 years or so, a component has had its price decrease and its efficiency increase. It also tells us that solar panels on a vehicle, even if they don't lead to huge benefit, make for great marketing.
There may be a use-case for a small amount of solar panels just to pump air throught the car to keep the interior a little cooler. These won't have to integrate with the cars charging or storage system--they'd just have to power some small fans
We had a Prius with a solar roof. Wasn't by choice, just happened to come with it since the car had all the other options we wanted.
From what I remember it would periodically turn on the vents to circulate air when in full sun. Also had a button on the remote to startup the AC, which only worked within remote range.
Both features did make the cabin relatively cooler after being in the sun for a few hours. This was moderately useful in Southern California.
At the time reading about why it wouldn't trickle charge the battery had something to do with radio interference, which I feel was just an excuse to avoid hooking up a proper charging system. Doubt it would have made much of a difference anyway.
Features like this are a huge boon for in-vehicle air quality.
Stepping into a new car that’s been sitting in the sun can’t be healthy.
I just wish parked vehicles could automatically crack the windows open, but shut them if it’s raining/snowing.
Maybe some geo-fencing so it only does it in relatively “safe” locations.
Would also be beneficial in cold weather climates: it’s colder at night, so it would be warmer when I enter in the morning if it let the warmer morning air in.
EVs can do this without significantly depleting the battery. Every Tesla keeps the cabin temperature below 105°F as long as the battery is above 20% charge.[1] You can also turn on the climate control from your phone, making the car a comfortable temperature before you get in it.
Our Leaf has a small solar panel, but it's for maintaining the 12v battery. It's much too small (it might be a 1/2 square foot IIRC) to the generate significant amounts of voltage and power needed to charge the main battery.
You can get a lot more than 1kWh per day from solar charging. It’s really popular on motor homes and narrow boats etc because you can actually get significant amounts of power.
Parking in full sun in an area with significant solar power isn’t something Everyone does, but for those who do a solar car could average 5kWh per day at 20+c/kWh for electricity and more for fast charging that’s ~1$/ day of electricity and 3600$ over 10 years. However EV’s can have significant discharge when parked, being able to trickle charge enough to offset this is worth vastly more than the value of the electricity you are supplying.
A solar powered EV isn’t a great investment, but with cars lasting 25 years the economics can work out. Especially if the car can directly use solar power and thus reduce the number of charge/discharge cycles.
PS: National average is currently 16c/kWh some states are much higher than this. Again people who have cheap electricity aren’t the target audience.
A standard perfectly installed 400W solar panel gets around 1.8 kWh a day [1]. Avg US electricity costs are 16c/kWh [2]. I think you vastly overstated the above.
So some may get better, but ~half of people will get worse. So I'd guess this is actually under $0.30/day.
>1$/ day of electricity and 3600$ over 10 years.
... i.e., if you park in perfect sun all day, every day, and there's no weather or seasonal changes, i.e., this is not possible. Picking a daily perfect value and assuming that value scales to all days is not a good estimate. Maybe, if someone is quite diligent and lucky, they will get 1/2 of the perfect value over time.
So I'm at $0.30 per day at best, avg maybe $0.15 per day over 10 years, i.e., under $550 for 10 years. And of course now your solar panels are slightly degreaded, slightly less power generated, and, if you're lucky, you might get another 10 years out of them (they're on a car after all).
So for a price of $2000, up front, for 20 years, you get $1k return. Of course, if you invested that $2K at 5% over 20 years you have $5300.
Justify why you think you can only stick a single 400W panel on a car. Cars are large 3D objects, you aren’t going to get nearly as much power from side panels or the dashboard as the roof, but solar panels are cheap.
Also, Mount Signal Solar had a 29.7%(average 2015–2017) capacity factor from it’s solar panels. That’s averaging 2.85kWh per day across multiple years from a single 400W panel.
https://en.wikipedia.org/wiki/Mount_Signal_Solar
Obviously most cars would never approach that but buyers are going to self select for better areas. How effective this would be in Alaska is irrelevant if nobody buys it in Alaska. California has both lots of sun, high electricity prices, and many people parking outside of shade. Hawaii doesn’t get quite as much sun, but is paying 45.4c/kWh right now.
>Justify why you think you can only stick a single 400W panel on a car.
Because a 400W solar panel is basically the size of a car (~1mX2m). And under IDEAL CONDITIONS, you're looking at a 150 to 250 hour charge [1] ... and you're not going to get ideal conditions most of the time.
Maybe you can stick 5 of those panels on a trailer and have the EV haul that around, and now you've improved your charging time from 250 hours to 50 hours (still, under ideal conditions) ... congrats, you still made negligible difference in extending EV range or making it practical.
>Cars are large 3D objects, you aren’t going to get nearly as much power from side panels or the dashboard as the roof ...
You're guaranteed to get 0 power from the sides that aren't facing the sun. So now you're horribly complicating the manufacturing process and increasing the EV price, all for an approach that would provide, at best, miniscule improvement to range.
>How effective this would be in Alaska is irrelevant if nobody buys it in Alaska.
It won't work in California either.
But let's try something else ... with EV manufacturers being obsessed with squeezing out every km of range, why do you think approximately 0 of them are actually building an EV with built-in solar panels? What do you know, that they don't?
[1] Assuming a 60kWh-100kWh battery and dividing by 400W = 150h to 250h
Ha, nobody's camper has 2kw solar on the roof. You've got a huge installation if you've got half that. Your roof has ACs, skylights, vents, ect to work around. I've got a 35' travel trailer I live in 4 months a year (and that's close to as bit as they get) and I think I could get 1,200w up there if I really squeezed. I took some measurements because I'm planning to.
RVs are often parked in full sun at least, but even then. I think I'd be lucky to get more than 5kwhh a day. Which is great for me as long as I'm not running the ACs. But that would not even remotely account for the extra drag it put on an EV to trailer it ten miles.
There've been attempts to make "solar paint" for cars, which would be lovely if possible, but even then I think the economic argument will essentially never work out when you factor in time value of money. As the original article said, the economics will likely always be much better for putting the solar panels on your house and charging at home.
It’s true many RV’s have a lot of random junk on their roofs but this discussion is about what happens if you optimize the vehicle for solar at the design phase rather than trying to slap whatever you can after market.
Did you watch that video? The solar panels are not even able to fully handle their appliances and AC, and they still use a generator to supplement. They aren't used for charging a car battery at all.
>but this discussion is about what happens if you optimize the vehicle for solar at the design phase
It still doesn't change the equation because you're not looking at a order of magnitude difference. In the case of RVs and the YouTube videos you posted, you don't need to worry about what happens if you 'optimize' a vehicle for solar during a design phase - just do a back-of-the-napkin calculation by doubling the output and ... nothing changes. The challenges are the same. The use-cases are still the same (namely, hope for sunny days to generate power to run some appliances). You're still not making any meaningful progress towards extending EV range - and that's assuming double output (and you're not going to get double in the real world).
That’s moving the goalposts you just said, “nobody's camper has 2kw solar on the roof” and yet here’s several people who do.
Clearly a camper that people live in has different demands for things like AC and a microwave than a car that’s just sitting around empty most of the day. A 15.5 foot long car is half the length and nearly the same with so downscaling a 3kW system to ~1kW seems perfectly reasonable.
Toyota built a demo by sticking solar panels on a stock Prius and says it added roughly 25 miles per day of range. That would cover the majority of what the average American drives per year. Yes most people would still need to charge their cars, but suddenly using a normal outlet at home rather than paying for a level 2 charger looks reasonable. So not only are you saving on electricity but also instillation costs.
>That’s moving the goalposts you just said, “nobody's camper has 2kw solar on the roof” and yet here’s several people who do.
I'm not sure where I've said that because I'm not against solar panels on campers or solar panels in general. Solar panels make a lot of sense in a lot situations. For example, I don't think it's a bad idea for an RV that is frequently off-grid to have them built-in to provide whatever power they can - after all, some power is better than no power. Solar panels on outside parking lots, that makes a ton of sense to me.
Solar panels for EV range extension does not make any sense.
>Toyota built a demo by sticking solar panels on a stock Prius and says it added roughly 25 miles per day of range.
Again, this is under ideal conditions, and it wasn't meant for range extension[0] (i.e. to charge the car while it's moving). But let's go with that for argument's sake .. so you're looking at a day of charging for 25 miles of range. 25 miles is approximately a 30 mins charge connected to the grid. That makes no sense. If you really want to use solar to power your EV just get regular rooftop solar and charge your car from your mains.
I said it and I didn’t mean “nobody” literally but it is very uncommon, even amongst people who do expensive solar installations.
And as the original article points out, when Toyota says they add 25 miles per day, they are doing so under nothing even remotely like real world conditions. They’re surely counting on full sun, flat driving with no air conditioning running, etc. An actual user likely wouldn’t even get half of that.
Actual cars much larger than 1x2m. The Tesla Model 3 a fairly small car and even that’s 4.7 m X 2.09m. Of course cars have a smaller roof if you ignore the hood, trunk, and the ability to have panels on the dashboard, rear deck, and side panels.
Also, you can approximate aerodynamic curves with multiple flat segments, current cars with a solar roof have then installed in a survey body segment.
>The Tesla Model 3 a fairly small car and even that’s 4.7 m X 2.09m.
Uh huh. Do you want to put some numbers behind your assumptions. How much do you actually think you can generate that would make a difference to a Tesla 60kWh-100kWh battery? How much extra range do you think solar panels would provide?
And finally, what aren't EV manufacturers seeing that you are seeing? It's not like solar panels on an EV are such a novel idea. In fact, it's the very first (naive) idea that everyone has as a potential solution to EV range and charging.
Currently there are 200W systems on real world cars that don’t cover that much of the car, but Toyota just made a Prius demo without changing the underlying design or using panels on the sides or dashboard which they say adds 25miles of range per day. https://global.toyota/en/newsroom/corporate/28787347.html
So, assuming 4miles per kWh that Prius was expected to hit over 6kWh per day. That might not look like much vs a 100kWh battery pack but it’s 9,000 miles per year when the majority of Americans are only driving 13,000 or less.
Their design doesn’t look practical, but 5kW/day in sunny areas seem to be a reasonable real world goal.
> So, assuming 4miles per kWh that Prius was expected to hit over 6kWh per day. That might not look like much vs a 100kWh battery pack but it’s 9,000 miles per year when the majority of Americans are only driving 13,000 or less.
I checked your link after reading your math, above. Coming from the RV solar world I found these numbers surprising. I think your comment about the 100 kWh battery pack is what threw me off. The normal battery in a Prius is 8.8 kWh with a 25 mile all-electric range [0].
Toyota is saying that the panels they used generate approximately 860 watts of power. The normal rule of thumb in the RV world (which I am familiar with) is to multiply panel wattage by 5 for watt-hours per day in good sun, so I would assume 5 kWh total per day for 860 watts of panels, in real life. So their numbers look optimistic to me, but aren't crazy - I would have said 15 miles under ideal conditions (5 kWh of their 8.8 kWh 25 mile battery), they said 44.5 km. They used 34% efficient panels to get that many watts from the limited space available on a car, something normally only available to the likes of NASA at this time (normal panels are around 20%).
Only people in places like Arizona and Texas would get most of that power output, others not so much. I don't think people realize how much impact clouds, shade and optimal panel angle towards the sun have on solar power output. Even partial shade, like form a sign post, greatly diminishes power generation, unless you want to wire the panels differently and loose early/late/cloudy power capacity.
For example, in 2021 Germany had 58728 MW of solar panels generating 49011 GW of power per year [1], which is 134.2 GW per day, which is only 2.3 times their panel capacity, and this is due to clouds. Based on this math that solar prius car in Germany may only get 5.6 miles per day of extra solar powered range with 860 watts of panels (860 watts times 2.3 is 2 kWh, or 22.5% of a 8.8 kWh 25 mile battery), or about 2050 miles per year, and perhaps a good bit less because the car panels are not oriented towards the sun like fixed panel installations usually are, and people park in shade under trees, or partial shade near telephone poles, or next to buildings sometimes, or winter when it's below freezing and cloudy the battery needs to warm itself to safely be charged, etc.
The only other thing I would add to this discussion is that panels fixed to the surface of a car may have problems with heat. Normal rigid solar panels are in frames and elevated, allowing air to flow under the panels and cool them. Panels loose efficiency with heat. Flexible solar panels, which don't need a frame and can be attached to curved surfaces, typically fail in a year or three, they are nowhere near as reliable as rigid panels. There's a lot of discussion about this in the RV and boating communities.
If the numbers work out on this idea, then that's great. Reliability would be my biggest concern, these panels need to last to pay for themselves.
>or dashboard which they say adds 25miles of range per day.
They made a prototype. They didn't say how much extra cost it would add to the car (and how it affects reliability, maintenance and safety). The cost of those panels has to be balanced by the fact that 25 miles is 30-60 min charge from your mains vs a day of charging from solar?
They also made a point to state this wasn't for range extension - i.e. when you're driving, that solar panel isn't contributing meaningfully to your range.
>Their design doesn’t look practical, but 5kW/day in sunny areas seem to be a reasonable real world goal.
You and I have different definition of 'reasonable'. Like I said, there's a cost to putting these panels on the car and the benefit is so effin small (even sunny areas have cloudy days and/or your car is frequently parked in the shade or indoors) that it's much more reasonable just to plug the darn thing into your mains and charge that way.
>Justify why you think you can only stick a single 400W panel on a car.
Did you bother looking up panel sizes? One large panel (5.4'x3.25') is most of usable car area. Sure, maybe you can put 2 or 3 - at vastly lower return due to being tilted towards the sun.
Do you really think that you can get more power over the entire surface of a car, when most of it will be tilted to the sun, as you can get from an entire panel optimally placed?
Go ahead and demonstrate.
>Mount Signal Solar had a 29.7%(average 2015–2017)....
Did you bother to check any of the math?
For example, the single 400W panel is a First Solar Series 6 440W, 80"x49", that and they use trackers to make them align to perfectly to the sun. Want to estimate what you'd expect from a car? I don't think you're putting an 80
x49" large flat surface on it, unless you want to drag losses to vastly outweigh anything else. Other panels in later phases are even worse when you think they apply to cars.
I'll never understand how people think the most ideal, large scale installation at ideal location, with moving trackers, will yield the same on a car with nearly zero surface at ideal angles.
>buyers are going to self select for better areas
How well are these solar cars selling in these best places? That might give you more insight.
If you cover a curved surface with solar panels you can approximate solar tracking in terms of power per given footprint. It’s less efficient use of solar panels but in a solar car panels are cheap relative to the value of energy produced.
Solar options on EV’s will always be niche. Probably less than 20% of people would see significant benefits. However, as the percentage of EV owners increases that ratio should stay the same. 5% of EV buyers (themselves 5% of car buyers) the market isn’t very many people. However if EV’s made up 75% of new cars then 5% of that is a more significant market segment.
For now I suspect cars with an extreme focus on solar will flop. But, a base model with modest styling compromises and 2 levels of solar options roof vs every surface could be quite popular. In the short term a solar on a van seems to be the obvious option with the smallest compromise. It’s stick with large nearly flat surfaces to maximize internal volume, so why not toss in solar.
> If you cover a curved surface with solar panels you can approximate solar tracking in terms of power per given footprint.
????
By approximate you mean lose signifcant energy?
A car is a closed manifold. Take the area it casts a shadow on - that is the area a solar tracker would get ~100% of the sun's flux. A general closed manifold (which is prefect for a car since the car and sun will move) will get ~50% of that energy. That's pretty massive.
A simple way to compute exactly 50% loss is for the area of a shadow from a sphere - a tracking disk with that area would get pi * r^2 of the energy. A sphere with the same shadow would get 50% of that (set up, integrate).
Do you even check these claims?
Of course you'll fixate on a sphere vs a car, but make any closed manifold, let the sun move throughout the day, and you will end up with pretty much the same result (via theorems on total curvatures on closed manifolds stuff).
I invent crap like this for a living for decades, with degrees in math, physics, and computer science, with grad work in all three, with a PhD. I'm pretty comfortable with my numbers.
So go ahead and demonstrate my lack of reality. Post your panel stats and math. I did.
Sorry - I read your comment as one lower and replied as if you claimed my numbers were nonsense :) I agree poster one up is not making reasonable estimates
> Justify why you think you can only stick a single 400W panel on a car.
Have you looked at the size of solar panels per watt and the flat area available on a car?
I have solar panels on a boat and the area is approximately (don't have measurements here with me) about the size of the roof of a regular sedan. All I could fit there was 110W worth of panels. If you have a long, wide SUV you can do more but only so much more.
In practice, those 110W worth of panels really only deliver 40W-50W to the batteries on a good sunny afternoon in California. The angle isn't perfect just like it won't be on a car which reduces output quite a bit.
It's worth it on a boat because I'm only charging the batteries to power the electronics so it's borderline enough. On an EV which uses tens of kW to move, it would be a microscopic contribution.
If installing on cars then we should assume the higher cost extra efficient cells that cost a lot more money.
On a car or small truck there just isn't enough sunlight to make a difference even at 100% efficiency (last I heard labs were getting in the low 40% range using tricks that probably don't apply in the real world). However for large motor homes (and possibly semi trucks) there is enough roof space to make a difference. Motorhomes often stop for a few days at a time so can get some useful range (or at least not use the batteries running the stuff inside).
In no case though is anyone thinking about saving money with solor on a moving vehicle. The large ones can possibly get enough range to be worth the extra costs even though it's costs more money.
Picking a daily perfect value and assuming that value scales to all days is not a good estimate.
What I'm seeing on this topic is a lot of folks that I can only assume have never spec'ed out and actually used a solar installation. Go throw some panels on the roof of your house and RV, and then we can talk about how "all we have to do" is put panels on a passenger car. Not one of the "all ya have to do" crowd has mentioned how efficient their solar installation is, how the math works. Nope, it assumes a spherical cow, yada, yada, yada, and the sun is always pointing at a direct 90 degree angle to the panel.
The 410W on our RV, for example, is good for recharging the house battery after running the microwave to make breakfast. If it's cloudy, you won't get to run the microwave for supper, but at least the lights can stay on. The most I've ever seen come out of that installation was 390W. I've not looked that hard at the charts, but I'd assume on average maybe 200W. A cloudy Seattle day? That's when we're glad we bought the bigger house battery.
I can't get you really good numbers without some work, but what I did do was look back when I knew it was not covered, and when we were actively using it regularly, and when the Seattle sun was at it's best: June and July. In other words, give the most charitable number possible. For reference, the panels sit flat on the roof and I do not adjust them during the day.
With some quick-and-dirty visual estimates from the charts, I'm coming up with about .85kWh/day. Yeah, I know, but I looked at it twice. I went back and looked at some other time periods as a sanity check. And <1kWh/day is what we get. In the summer. Right now the RV is sitting in the drive with the panels uncovered, and the driveway is sloped and slightly angling the panels to that sad little January-in-Seattle sun. Yesterday the panels cranked out a massive 0.1kWh. That's right: enough to run a 100W light bulb for an hour.
Despite all that, it's enough to run the microwave a couple of times a day (which is really the only large draw the RV has), watch some TV, run the lights at night. And if the panels can't keep up, that's what the giant-ass 300ah lithium house battery is for.
Well, yeah, it's just a "Library of Congress" measurement that is probably long past its expiration date. The entire vehicle's interior lighting is LED; on the monster house battery it has, you could probably keep it well-lit for weeks.
Motor homes and boats have a lot more surface area than a car roof. The 1kWh/day is based on the two actual cars with a solar roof, which have a ~200W capacity. Even a paper optimistic about solar cars estimates that doubling that to 2kWh/day needs 800W of solar panels installed on every available surface of a car, i.e. also on the hood and doors. [1]
> There is no way the extra weight won't offset that.
Solar is surprisingly lightweight the 1kW per day Hyundi solar roof was installed in a 60 lb panel. That’s slightly heavier than a steel roof, but not by that much especially compared to a 4,414 lbs. car.
Their next designs looks to be adding a solar front trunk and easily doubling output.
It’s really popular on motor homes and narrow boats etc because you can actually get significant amounts of power.
It's really popular because it's solar or nothing in a lot of cases. That, and those large, flat surfaces make for convenient mounting on a surface that otherwise isn't getting used. But it most certainly is not because it generates "significant amounts of power". I have to wonder how many RV and boat owners you've actually spoken with to come to that conclusion.
but for those who do a solar car could average 5kWh per day
I'm not even going to bother with doing the math to refute that, as that is laughable fantasy.
> A solar powered EV isn’t a great investment, but with cars lasting 25 years the economics can work out. Especially if the car can directly use solar power and thus reduce the number of charge/discharge cycles.
I'm not going to retain my EV for 25 years, simply because I'm expecting more innovation to happen in the EV space. But I'll be damned if I'm not buying my motor home or boat to last for at least 2 decades. That's the key difference.
> It’s really popular on motor homes and narrow boats etc because you can actually get significant amounts of power.
Depends what you mean by significant I suppose, but unless you have tons of square footage for panels (like the whole roof of a house), you're not getting a lot of power from solar.
Have you done solar installations and tried to live off the power they generate? It all sounds great until you do the math and realize how little power you have.
I have both a boat and a travel trailer and spend occasional time living off the grid on both. You quickly learn to be very frugal on power.
> a solar car could average 5kWh per day
How much roof surface area you'd need for that? Is there a car large enough?
> Remember while you are parking your car in said parking spots you are also baking the insides so in weather above say 55F, it will get quite hot and probably need to turn on the HVAC systems to cool the cabin and/or battery periodically.. wiping out some of your solar charging gains.
Only if you are choosing to park in the sun instead of parking in covered parking. That's almost never a choice your can actually make.
The real utility of solar panels would be for driving in areas that don't have utilities (places to charge) near enough to charge from. Though, in that case, it still makes more sense to carry separate panels folded in storage than to integrate them into the roof.
Tldr if you do everything wrong, like we say you will, then it will not work on some edge cases that we state they are very important for all people at all times.
> You can build a small installation for your house
* 30% of Europeans rent. 50% for Germany.
* 46% of Europeans live in apartments. 63% for South Korea.
It reminds me of the whole "just install a charger at home" argument. It simply isn't an option for a large percentage of the world and alternatives will be needed. Solar cars may have some impractical elements but at least it's workable.
If you live in an urban dense environment like South Korea or Western European city, what wide-open, unobstructed, no-shadow&shade parking lots are you parking your car in?
It's like sure, in Manhattan no one has a charger at home and most people live in rentals.. but also the cars are all parked underground or street parked on shaded side streets, so....
I assume you haven't actually been to these cities.
Because it's not like the entire city is a massive Shinjuku with ultra-high density and no sunlit spaces. It is mostly open places e.g. parks, regular housing, office zones etc with concentrations of apartments in select areas.
And it doesn't address the point that 1/3 of Europe rents and can't just add solar panels.
I have been to many of these cities, and I am thinking in percentage of consumers not percentage of land. Given the density of the dense areas, a quite large percentage of people live in these areas.
Beyond that..
Yes Tokyo is a big sprawling city with lots of low-rise neighborhoods. However it's not like Tokyo really has street parking there either. Most of these cars are going to be underground. You need a permit in many areas of Japan certifying you have off-street parking for any car you purchase. So again, Tokyo is not like NYC where people just street park cars all over the place. That's why people complain about the urban character of US vs W Europe/Japan/etc.. most of those places don't have the "car culture" of America.
You don't even need to add solar panels. Just being within 50ft of a 110V outlet one night a week is going to get you as much charge as these solar roof pipe dreams.
There's a reason basically none of these have gone to market and the startups proposing them are either bankrupt or on the verge of it..
Western Europe city resident for more than 30 years. Medium sized capital. "Sunny" is what they call this place.
A very large part of the parking space in the city is underground. Almost all housing with parking space have it built under the building. Here "regular housing" is apartment buildings and there are only a few smaller areas with single-family houses.
Most recent shopping malls have underground parking too. Only a handful have open surface level parking and that's the ones outside the city. Not just shopping malls, the trend for smaller supermarkets currently being built is having inside parking. As for parks... most just don't have any parking space. The two or three that do, it is indeed open surface level parking. But most parks in the city just don't have parking space. You walk there or take public transport.
There is, sure, parking in the street. And this is generally a sunny city, as I said. And yet, a large part of street parking space available is under tree shade and/or under a building's shade for most of the day. A street where you can park and that is wide enough to get more sun will very likely have trees planted.
So... yes, there is a lot of sun here, there's no discussing that. But the city is just not built to let parked cars get those sun rays.
----
On the other hand, yes, it's not feasible for a large part of the population to put solar panels up at home. That is undeniable. Some companies are trying to come at this from a different angle: they are promoting installing solar panels as a shared resource for the whole building. The downside is that usually you don't use it, but just sell it back to the network. But it does produce an extra source which, at the end of the day, is what counts. It may not be the best solution, but it's what you can do.
The Netherlands has a lot of parking next to the curb. So you can't install a private charger. Houses are often low enough that there will be sun on the car for quite a big part of the day.
The 46% and 63% you mentioned probably live in a city with many apartment buildings, so it would be really hard to find a spot where a car could get significant sunlight. When I read the first half of your comment, I thought it was against solar panels on cars. Certainly this will not help you if you want an alternative to not installing a home charger.
I am part of the 46% of Europeans who live in apartments and my house already barely get any sunlight during the day living at the second floor, the lights are on during the day if I want to see something that is not on a monitor. Cars are not lucky enough to be several meters above the ground to get more sunlight like my house, here in Milan the few places that are not covered by buildings are covered by trees.
If they live in an apartment in a dense city then EVs aren't the solution anyways: e-bikes and public transport are, not clogging the city with electric SUVs transporting mostly one person at a time.
If you live in an European city you are probably already using the public transportation, plus cities are now full of e-bikes and e-scooters, this was not true until a few years ago, so yes, it is already happening, particularly for the 46% of Europeans you mentioned earlier.
I report my experiences in living in a European city, if you don't believe that most people already use public transportation or that cities are not full of e-bikes and e-scooters you can always visit one.
The statement was not 'market for cars is zero'. The statememt was " public transport and bikes will do most of heavy lifting".
its expressed in passenger-miles, not $$$. Looking at $$$ does not consider efficiency.
If you wanted to look at $$, what is the size of public transport budgets, markets for tickets and bikes?
It is irrelevant who uses public transport, bikes or not.
Because the European car market (which is larger than the US) needs EV options. And those options will need to factor in the conditions in those countries namely that there is a comparatively higher number of people renting and in apartments.
Car markers clearly understand the problem and the opportunities here.
On EV - Newer buildings tend to have underground parking(s) with possible charging stations. But that's it - personally I'd consider a solar panel on the roof of a car a total waste of resources.
Even if I've got a house, the car will be parked in a garage or under the roof, no (solar) charging there. Solar panels on the house roof are a whole different story.
In most of the EU larger cities is next to impossible to go work by car. If the office is outside the city and it has a large parking area - yes, but that's quite unlikely.
Factually untrue, I live in a very large German city and going to office by car is completely normal. Where are you even getting this obviously false information from? Are you frequenting r/de on reddit or what?
However, if we simply reduce the hyperbole "next to impossible" to something like "uneconomic" or "inconvenient" then we are getting closer to the truth. The only exception which MIGHT be somewhat close to impossible is Freiburg which is comparatively restrictive towards cars. Its population consists largely of economically weak students though, so it fits the crowd.
Taking the car to commute to the very center of cities is an economically senseless thing to do in large urban areas in Germany unless your commute is from the outside of the city. Public transport and bike infrastrucutre is mostly good enough for most people despite large room for improvement, especially when looking at Netherlands or Denmark for comparison.
This is also something that is VASTLY different from American ways of providing mobility, the situation is not comparable at all due to the average commute distances involved which are orders of magnitude higher in the US.
I am tempted to reply to that - zero idea where reddit (esp. /r/de) has come from. My experience with Germany, it's one of the most decentralized countries in Europe, going by train is pretty normal (parking near various train stations, outside the city is quite standard as well).
"Next to impossible" comes from the traffic and how expensive (along how lacking) the parking in city centers is. I have lived in 4 different European counties and visited almost all of them. Germany wise (not lived) - I'd not consider Frankfurt, Berlin, Stuttgart or Munich a place I'd like to drive to work every day. Dusseldorf was better, but still. Many EU capitals are pretty much hell just to drive through - I am hard pressed to say, "yay this one was ok".
Most of the larger cities are just not designed to the amount of cars there are - the roads are relatively narrow too. (Also the parallels to the US are funny - I have lived all my life in Europe, visited the USA but that's all)
There's the benefit of figuring out mass market car integration. It may be we have to rethink what a car is - competitions like the American Solar Challenge show you can run minimal cars for thousands of miles on solar: https://www.americansolarchallenge.org/ - which is great, but they will never address mass market industrial engineering.
Wind powered cars are possible and pretty cool. Turbines could use the apparent wind to generate just the same way it’s used by sailboats to go faster than the wind.
They are an electrocution hazard, the voltage on a string of panels is several hundred Volts, enough to die. One can build a fool-proof system, but the current devices and connectors are meant for static configurations handled by a qualified installer. You can DIY, but most people cannot do that safely.
Also a 500W panel is ~ 20 KG (~45 pounds) and an MPPT can exceed that weight. For a car with a battery that is tens of KW, any portable system that is less than a few KW is not very useful, charging the car 5% per day is not feasible for most.
Why portable? Are you going to tow it around? With what, the car you are trying to charge super slowly.. but have no increased its driving consumption rate by 100%?
You can simply get a ground based solar install at your home if you can't install on your roof. But really $1000-4000 does not buy nearly as much solar as you are assuming. Go google "off grid solar kits".
You are better off hooking that up to your home than your car, as the hours it is generating power your car may not be home. If you add a battery to try and solve that problem, the battery will consume 90% of your budget. Don't forget there are fixed costs like the charge controller, and any electrical work to tie the solar array to your home. So your fixed costs alone are in the $1000-3000 range.
One way to approach the engineering question of how to make solar cars for the mass market is to push the car body design to be extremely efficient. Aptera's three wheel, two seat, design seems more likely to deliver the type of daily range extension that will make solar cars a contender in the market.
Depends. There are venture capitalists who are looking at the interest rate shift and claiming they are shifting away from low capex lottery tickets to taking another look at high capex, especially if there are fanatical buyers on the market.
That said: 1. VCs say a lot of things, and don't always put their money where they say they do. 2. It's troubling that aptera is going for even more equity crowdfunding, and that they are throwing a lot of their fanatical (first mover) supporters under the bus by preference exclusively to crowdfund investors, it's a sign of desperation.
VCs were pushing "let's build things" puff pieces about infra/physical production/goods/supply chains, at the same time they were going full degen in crypto/de-fi/web3 so.. haha.
The problem is that bringing a car to production is incredibly hard and incredibly expensive. Even in the best of times where the market shoves free money into you, its incredibly hard to get a mass production vehicle to market.
Lots of EV companies were high on cash and most still couldn't get a car into production.
Trying to do it now where it is way, way harder to raise massive amounts of cash is incredibly hard. And this start-up has already gone bust once, and are trying to bring a vehicle to market that is quite complex and has limited appeal.
I would not imagine range is the issue for a two seater, 3 wheel car. That sounds like it would be used for short trips and would lack the luggage space I want on a long trip. Also, I'm not interested in driving a tiny car on high speed trunk roads.
you are mistaken. its combination of aerodynamics and composite bodyweight give it particularly excellent range. also as a byproduct of the teardrop aerodynamic design it actually has a somewhat absurd amount of luggage space. third it is not particularly tiny, no more so than any other compact. fourth its design tradeoff (the bodystyle) is specifically most relevant at higher speeds when drag is the predominant energy factor, its made for high speed trunk roads.
The aerodynamics and lightweight of the Aptera means it can get 1000 miles on only a 100 kWh battery, 10 miles per kilowatt, twice as efficient as the Tesla Model 3. It is so efficient that in California sun, its solar panels can generate 40 miles each day. It is also available with smaller batteries with only 500 or 250 miles per day. People who don't drive more than 40 miles per day might never need to charge their Aptera. Overview: https://www.youtube.com/watch?v=mpiH-Y-HOvE
That's kind of funny because I considered buying an Aptera specifically for long trips. A 1000 mile battery and a 40 minute recharge time at only 40kw makes it ideal for long trips. Especially with very few 100kw chargers on your route. The cargo space is large because it lacks a back seat and on our Fit we always fold down the back anyways.
If you have kids, or a ton of stuff you need to carry I would recommend a Prius Prime instead.
Except a Maybach from the 2000s has a PV panel on it for powering the Aircon and built in champagne cooler
https://www.autoblog.com/2007/10/19/its-friday-300-000-car-w...?
Sure, solar panels on low end EV cars are unnecessary but if I'm paying six figures for a sporty golf cart I want a solar panel to keep the inside cool. Theres a segment of the automobile buying public who will purchase a car with one integrated over others that don't.
YES.
The benefit of solar canopy over L3 charging station is almost more in the protection from sun & elements than it is the actual electrical generation.
A single car parking spot worth of canopy could maybe generate 20kWh per day being very very optimistic... meanwhile L3 charging users pull down 20Kwh in about 8 minutes of charging.
I agree that it’s generally not enough, but it feels really well-aligned.
It offers shelter, prevents the car from overheating, distributes resiliency where people need it, reduces the dependency on electricity transport infrastructure, answers the annoying question about the fossil-fuel-dependent grid, etc.
But I agree: you don’t want just the loading section, but every parking lot to be entirely covered, resting area, play pen and access road too. Mainly because those are available areas that could use the shelter and, if anything, for more marketing: brand the panels to make the fast chargers in the corner of the parking lot that much more apparent.
I actually would rather have a (slow) charger at every spot in that lot, to tell all car users: if you had an electric car, you could fill up while you shop. No need for the big fast one.
More so: even then, you are still right that we need more. Have agri-voltaic near the fast chargers to show people how those work, or non-polluting industry that need large amount of electricity: Hydrogen generation maybe? It would reduce the dependency on infrastructure. It would be striking to have people take a break from the road near modern installations that demonstrate that we can have less polluting options.
Hell, solar panels on houses make no sense either - unless you can store/use the power locally(which many houses cannot) and don't have land to put them on the ground.
Better to put all of them in a big field. Easier, safer, and cheaper to install and maintain.
Right, solar on building roofs is fine and good, it's not nothing, but it's not a serious way to grow renewable energy. It's thinking far too small-scale.
If the grid is fully modernized and using 99% renewables, there are very few reasons to want photovoltaic panels on cars. So you focus on what's cheap and scalable.
I note that among the costs for the inefficient car+solar combination, that the CO2 emissions just to make the panels, the inverters, the controls, and the assembly are not mentioned. The article does compare the install on a residential roof -- indicating far greater efficiencies are obtained, without the cost of using extra electrons to carry the extra weight of the aforesaid 'extras'.
Aptera, has been suggesting this and going bankrupt at least once, while 'trying' to get to mass production. Their delays make Tesla look positively lightning fast (see, Cybertruck).
Some of these companies going nearly bankrupt before they've even started production is telling. When you are just designing the thing, your costs are basically staff. Now trying to scale production you have all sorts of capital expenses and then operational costs that don't get recouped until you have scaled production enough.
Designing a car is not a hurdle.
Building a prototype is not a hurdle.
Having 20k pre-sales is not a hurdle.
Actual serial production in an operational factory able to ship 10k+ year is your first hurdle.
Doing the above while selling the cars for enough money to not go bankrupt, while opening some sort of service network for the cars .. is a big hurdle.
Getting closer to 100K/year, is the next real hurdle.
And being a real big boy automaker in the 1M/year range is
That Aptera that went bankrupt was actually a diesel-electric hybrid, supposed to achieve 300mpg. They had to close shop when they didn't get the funding they needed.
The founders went on to other things for a few years. Now they seem to be making pretty solid progress. I don't think putting "trying" in scare quotes is justified; launching a car company isn't an easy task.
The german company Sion [0] is close to launching a reasonably priced, solar covered car. For me, their open approach is more important than the solar panels.
They have a strong commitment to the community and are transparent and publish regular reports and insights to their progress. They also take a open-source aproach to maintenance, basically releasing everything you (or your local repair shop) need to fix things, and they try to choose readily available parts when possible.
Yeah, I know and this was what I most feared would happen as I kept an eye on this project over the years. It was always going to be a long shot, but one worth giving a go.
The article doesn't consider that in a lot of European cities curb-side parking is very common. People have no garage and usually drive very few kilometers.
Of course solar panels cannot provide enough power to drive a car for any significant distance, but that doesn't make them useless.
I know, because I put solar panels on an ICE car's roof several years ago. They charged a recreation battery in the boot, which I used to charge my phone, headlamp, camp lights, laptop, radio, smaller power bricks...
Fantastic for camping, and it lets you jump-start your own car.
The article's prices are for first-party solutions; I paid $2/W and it's been zero maintenance over highways, bumpy tracks, heat, car washes, and frost. Using amorphous cells instead of monocrystalline can net you a bit of energy on cloud/rainy days too, even if they are less efficient in bright sunlight.
If you have roof rails or a pickup canopy, give it a try. The hardest part is finding a way to get the wires into the interior. Don't forget some soft cushioning washers in the mounting nuts and bolts.
I have two 100W panels on top of the Jeep I drove around Africa for three years. They charge a secondary battery and run the fridge, the water pump and UV Filter, camping / interior lights, all my chargers and laptop charging. [1]
I also had a 100W Panel on the vehicle I just drove around Australia for 18 months.
Those articles miss that there are many vehicles, not just individual cars. Some use cases combine well with a vehicle being outside, slow, and not going far. Aptera is an excellent example of a fun vehicle that leverages its aero-dynamism.
I’m not sure why the boxer van market isn’t the most obvious candidate, both for delivery companies (extending an otherwise relatively short radius and lowering the cost of battery seem well aligned) and camper-van, where the autonomy sounds worth the cost. Big rigs also feel like the perfect candidate, assuming someone can figure out how to attach panels when the load is detachable.
Trains are fantastic options, although not as perfect as having panels along the rails. Airplanes, even more so — although, yes, integrating into the structure isn’t a done deal.
Rickshaws are another obvious example: they can run without pedaling if the whole roof is a solar panel. There’s also a more accessible version of a bike for road trips that could leverage the bicycle-with-a-roof format well.
Boats are surprisingly appropriate candidates. Leisure boats, in particular, are mainly used when it's sunny. The water offers extensive cooling available. There are electric waterboards that might not have a roof but still have enough surface to be promising—although I think a new format, akin to a wind- or kite-surf, might make more sense.
Too much of the logic starts with assuming people are driving a sedan or an SUV. That’s a terrible idea. It already kills millions every year. We can’t let that lack of imagination also kill electrification.
FWIW: on the other hand covering a EV charger spot with solar in a clear environment can almost pay for the net charging done as long as you have a battery local that can buffer.
Solar panels on cars are fine. The problem is marketing it as some revolutionary feature that differentiates from the rest of EVs, when it should just be a bullet point next to weatherproof floor mats.
Perform studies, get real numbers, otherwise, you're just going to get a bunch of disappointed customers.
Having to think about where to park my car to maximize my range is only going to add to EV range anxiety (not lessen it) if you don't have a reliable place to charge.
Panels are installed in locations and at angles to avoid shading as much as possible, but when you have the panel on your car, you have none of that luxury
That sounds like a shortcoming of implementation, not proof that the concept is bad. Yes, I'm suggesting that cars with solar panels should have tilting, sun-tracking roofs.
Not that it matters. The reason cars do or do not come from the factory with solar roofs is sales. If the market pays for it, it stays. If they don't, then it goes.
I've seen countless people pay thousands of dollars for "ground effects" which are nothing but painted plastic glued and/or screwed to the car body, chrome packages, blackout packages, and 'leather' seats that are actually vinyl and less comfortable than cloth. A significant portion of the automotive market is driven by aesthetics, misinformation (e.g. 'leather' seats), and consumer fantasy. How many dudes driving huge diesel trucks do you see actually towing heavy loads or picking up shipments at a loading dock? This is just the green version of the same fantasy marketing.
Incidentally, I would love a solar roof if only to power a fan to keep air circulating when I have to park in the sun, and to trickle-charge the battery when I'm away on vacation. Not everything has to be an ideal solution to powering transportation.
Tesla should offer that. They have so much electronics powered up when the vehicle is off that it runs down the battery.[1]
Having a solar panel won't save much money, but at least you can drive a bit every few days during a major power outage. Something that's becoming more of an issue as infrastructure becomes less reliable.
This seems like way too much concern over a minor luxury feature. The only borderline alarming claim is that this sub-optimal use of solar panels will take away from the limited supply of materials, but on this scale that sounds highly unlikely, and no data is provided to cause concern, just speculation.
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[ 3.5 ms ] story [ 235 ms ] threadPeople seem to do the math and get maybe 5-10 miles of range per day. I’d say that actually quite useful. Especially if you only drive around town or leave your car for days at a time.
Or imagine running out of battery in the middle of nowhere with no phone reception. Just wait a day and keep driving to a better spot. That’s really useful.
Finally this ignores the idea of having panels that fold out when you park. You could easily 4x your solar collecting area and get some real range.
And beyond that it’s harder to call for a charge up than for a can of gas. So options might also be limited.
Not bad value add.
The article describes options less than 1 KW, at home you put 5-20KW, it's a very different kind of beast.
If your home uses gas/oil for heat & hot water, you might only use, say 20kWh/day in winter and 35kWh/day in summer. This matches pretty well with the amount of solar generation you can put on your roof! The cool thing too is that you get more sun in summer, when it is hotter.. and you use more electricity because of the AC.. so it matches pretty well!
Now that same 20KwH in winter is enough to fill 20-30% of your battery of your EV to drive 60-80mi. Your little car roof will generate minuscule amounts of power by comparison to your entire homes roof, while also being at the wrong angle, sometimes parked indoors or in shade, or in motion & not charging during daylight hours.
How much charging time gets consumed back by the panel fold in/out movement?
Does the car now need an interface to allow the user to select when to fold out (long planned parking only?).
This is not set-it-and-forget-it convenience.
When the Aptera announcement came out, I analyzed my fuel receipts, and concluded that I would plug the car in 2-3x a year (occasionally I find myself in Chicago or other day-trips), but the rest of the time solar would more than cover my usage. And that's assuming some hefty derating for latitude, cloudy weather, etc. I just don't drive that much, but when I do, it's places and times that aren't well served by transit so I very much need a car.
If I go back to working at the office and solar only covers a portion of my driving, that would still likely mean plugging in once a month instead of once a week without the solar, which is still pretty cool.
I think this article is "it's not a 100% solution so therefore it's a 0% solution", which is a pretty tired tactic at this point.
Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway..
This comes up every time, and it's simply not an option for the vast majority of the US population.
Once we are down to the subset like the person I responded to who claims to need a car AND to only travel 5mi/day or less.. maybe! Or I mean, isn't this why we have uber?
If one was to drive only 5mi/day at 30mph, that means the car is not in use 99.31% of the time. Only driven 1,825 miles/year. What percentage of Americans drive less than 2,000mi/year? The average is closer to 15,000mi/year.
Dealing with costs&time for car, insurance, regular maintenance, registration, emissions inspections, etc... for something you don't really use? A lot of these are fairly fixed costs regardless of mileage. Probably end up spending like $3/mile TCO at such low mileage rates.
This kind of car is great for me.
And it’s more comfortable — you can do it when you’re tired, sore, or sick, in the rain snow, and heat.
There is nothing that is going to usurp personal vehicles anywhere but the very densest cities without changes that are infeasibly expensive and trample on people’s property rights. The new hotness is walkable areas surrounded by parking so you only need the car when you leave.
Your "running out of battery in the middle of nowhere" scenario doesn't make sense. If you're that close to help you can walk there in less time than it'd take to charge the car.
Besides, EVs don't suddenly run out of battery like you imagine. Batteries display state of charge very accurately, so you'd know way ahead of time if you shouldn't be heading towards middle-of-nowhere. But even then, EVs don't run out of battery suddenly, but gradually lose power and get slower. To get stranded, you'd have to be a fool ignoring all predictions, satnav, and then stubbornly drive slower and slower for 20+ miles while all the warnings are beeping at you.
And there are RVs. Some people use solar panels on cars as their only source of electricity!
ICE cars also have batteries, if that gets flat, car is not going anywhere. Solar panels can be quite essential, if vehicle is parked for extended periods. It is not just some rounding error!
Why doesn't my sedan? Tesla needs to release a Model S with a microwave, fridge, spare tire and bed!
That means less batteries, less lead in nature, more green stuff, happy Gaia...
And even EVs like Tesla has slow discharge. It makes sense to put small solar panels on top, so they can do firmware updates.
https://hackaday.com/2020/03/10/solar-panel-keeps-car-batter...
If you have street parking only it is questionable whether you will be able to leave a car a whole week without incurring the wrath or a municipal agency. If you have parking lot parking only in an outside lot at an apartment complex of some sort, you might prefer a panel, though I more that you can get a kind that you leave on the dashboard that plugs into the lighter socket for a similar price —without the convenience of an integrated form factor admittedly but still.
The path to mass market EVs is having good charging accessibility and low prices. Adding more cost and telling owners to remember to park in the sun is not it.
Not everyone cares about EVs.
Hmm. I just bought a new 36 month battery for $110. Never in the last three years did I have any issues with the battery not being "preserved." $2000 of solar for no measurable impact on the usability of my ICE? This doesn't make sense. $2000 buys me 50 years worth of 36 month batteries. The only time you would need trickle charge is if the car is parked for long periods of time with no plug-in available for trickle charging. That's a niche need. Plug-in trickle charge for the life of the car would cost a lot less than $2000.
RV? When parked with no plug-in power available, sure it would be nice to have some electricity without having to run the motor. Other than that, the tiny bit of solar you could put on the roof is completely insignificant with respect to the power needed to move the extremely heavy RV.
For RV and boats I think solar panels make most sense. But it is not for moving the vehicle, but to charge a alternate battery that is mainly used for electronics, tv, computers and maybe, maybe a fridge...
1° the Lightyear Zero is actually in production. There is no reason to think the cars built won't be sold soon...
2° the lightyear 0 has a sophisticated series of controllers for its solar cell that can activate solar cells independantly, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade.
3° dust doesn't reduce solar output that much. Washing the panels once a year is generally enough, and most people wash their cars more often than that.
I love back-of-envelope calculations to check for lies, but they shouldn't preclude making your minimal homework first...
Aka just putting a single bypass diode on every cell, it's not complicated.
And it seems like the whole company might be bankrupt.
It was an extra $50 to get a controller for our RV solar that has that same functionality. MPPT solar chargers are hardly “sophisticated“ anymore.
Speaking of chiding others for doing homework, the Lightyear is no longer in production:
https://techcrunch.com/2023/01/23/lightyear-stops-production...
And why not, it makes a lot of sense. Most cars don't drive most of the time. And if they are catching any light, you basically top up the battery a little bit for free.
Or put differently, that's energy you don't have to pay for. Yes, it adds some cost. And it saves you money. Kind of balances things out pretty quickly. And it adds some convenience for day to day use where you add enough power that you don't have to go to a charger so often. Especially for short commutes, this makes a lot of sense.
Dust is not a big deal. Indeed nothing a good old car wash can deal with. Or a bit of rain. Panel degradation happens very slowly otherwise. I don't think that's a huge concern.
Right now in terms of likely to survive five years in EV land, you can rank Tesla>Rivian>Lucid>Fisker>Aptera>Lightyear .. and there's probably some other clowns I am forgetting. Like Lordstown, Nikola, Canoo, Faraday, Bollinger and Vinfast!
Vinfast has a higher chance of being alive in 5 years than Aptera. At least they've made a bunch of (pretty bad) cars.
Of the above list, if 3 of them beyond Tesla are still around on the other side of whatever recession is pending, and actually shipping cars in the 10k/year++ range, I'd be shocked.
Rivian is dropping money like there is no tomorrow and they survive because they razed unimaginable amounts of money.
Tesla isn't even in that league anymore, they are more profitable then all other car companies (outside of Toyota). Its more likely some of those will bust (or merge) before Tesla will go bust.
If I had a penny for every time one of the EV startups claimed this.
They go into production and then 1 year later they have like 20 produced and the year after that 100.
And then the often go bust.
That happens. But you see a lot of good ideas being copied. I think there are already several bigger manufactures that have announced solar panels as an option. A bit gimmicky for some of them of course. But its an easy up-sell and they love up-selling.
Solar panels are widely used, widely understood to work, and the economics are trending to the point that you can slap them on just about everything. Like cars. Kind of obvious when you put it like that. Which is why that is a thing that is starting to happen in the car world right now. The couple of square meters of roof and hood provide a tempting target. You get maybe 2-3 kwh out of that on a nice day. That's 10-15 miles in an efficient EV. For most commuters, that would be very tempting and it might even be close to all they need on a daily basis. Meaning they'd be able to stretch their battery over weeks or months of use in between charging. Add grazing some free kwh at the supermarket or other places and it's perfect for people without the ability to charge at home.
This is undeniably true. The catch is how very little that "little bit" actually is.
I have both a boat and a travel trailer powered with solar (I occasionally plug in the travel trailer but the boat is 100% solar-only). And I've been planning on adding solar to a truck camper. So I'm a big believer in power independence through solar and I'm fairly familiar with the pros (free electricity off the grid) and cons (so very little power). For my use cases it just about works, by being very frugal with consumption. But these are use cases where the typical consumption is in the tens of watts.
An EV uses tens of kilowatts to move itself. Three orders of magnitude more. Trying to run that off its own rooftop solar is akin to pouring a cup of water into Lake Mead to bring up the water level.
Wiki: he company announced in December 2022 that production had begun, at a rate of one car per week. Availability is currently limited to customers in the EU, Switzerland, Norway and the UK.[4] However, in January 2023 it announced that production of Lightyear 0 has been suspended to redirect their efforts towards production of Lightyear 2
Following to source article: Helmond based Atlas Technologies which is responsible for production of the Lightyear 0 solar powered car, was declared bankrupt on Thursday, with the loss of 620 jobs. Parent company Lightyear had asked for court protection from creditors for the unit earlier this week, after announcing that production of the 0 model would stop. Read more at DutchNews.nl:
Their design is based on a hyper efficient car, with a smaller, and thus cheaper battery. The solar panel is a small benefit, but would overall provide the car with more range per kg and $.
But to become affordable it needs major investments for reaching mass production, which nobody wants to do.
They still have the holding that owns the IP, so I suspect they will try to sell parts of their design to other car makers. Especially their in-wheel motors are very efficient.
I think the EV startup and SPAC IPO craze is really the final blow out top of the ZIRP bubble.
Look at mobileye for example. Instead of trying to mine gold, sell shovels.
In the crazy tech/EV/ZIRP VC-funded bubble, especially the final SPAC-it-rubes IPO cash-out phase... everyone was incentivized to raise way too much money as long as they pretended they'd be able to target and user market of billions. Sort of mutually agreed delusion.
Their IP wont be worth all that much.
Honestly, it was pretty clear from the beginning they wouldn't make it. Starting a car company is insanely difficult. And they arrived right in the Wild West of free money and EV scams with a car that would be incredibly hard and incredibly expensive produce.
Without some absurd raises in money like Rivian or Lucid (Saudi money) you are simply not gone do it.
Short version: adds weight and maybe $2000 manufacturing cost to the car. Best case current tech it maybe adds $50/year of electricity to your car, requiring you to park outdoors, in good FULL sun, in parts of the world that get a lot of sun-hours-per-year. Further solar roof of a car is not at the idea angle that a home roof is.
Remember while you are parking your car in said parking spots you are also baking the insides so in weather above say 55F, it will get quite hot and probably need to turn on the HVAC systems to cool the cabin and/or battery periodically.. wiping out some of your solar charging gains.
Aesthetically, tt replaces the lovely glass roof many EVs have and so makes the experience worse.
If you have a garage charger or charger at work, this is rounding error and irrelevant. If you don't and need to fast charge regularly, the fact that your car adds LESS THAN 1kWh/day from solar charging will save you.. 24 seconds of fast charging, per day of solar charging.. lol.
* EVs are already ridiculous heavy.
* $2000 is a blip in the price of a car and will be recouped.
* You often don't have a choice whether to park in sun or shade. At least a solar roof gives you some benefits.
* Large percentage of the world don't get to decide to have chargers at home/work.
Also you don't seem to be aware of this but $2000 is a lot of money to some people -- It's more than they spend on personal transportation.
* The attitude "$2000 is a blip" is why electric cars are expensive.
* People without home electricity (or who live in dense urban areas without parking) are not the market for the car at this time. There is no reason to make everyone else suffer out of theoretical concern for people who don't even own cars now.
* People without home electricity are exactly the market for this car.
* Who is suffering exactly by offering this as an option ?
$2k on a target $35k mass market EV is not insignificant.
I still stand by the idea that the Venn diagram overlap of "people who can't charge in their own home or work, even on L1" and "people who live somewhere rural/suburban enough to have completely open to the sun parking" is quite small.
L2 charging at a the grocery for 30-45min while you shop will get you as much charge as these solar roof pipe dreams would get you in an entire work week parked in a sunny field of dreams.
Hard to imagine a blackout so long that this would make a difference, that still involved having places to go inside the city, but in theory it could be useful.
Plus it's not from fossil fuel, which you probably care about if you bought an EV.
Probably won’t be recouped while you own it. It’ll be many years down the road. TFA covered this, perhaps a rereading is in order. Because what I’m hearing is “every little bit helps”, when in fact that’s not practically true.
> $2000 is a blip in the price of a car and will be recouped.
If a $2000 price increase saves $50/year (approximate numbers) then it would take 40 years to pay back. But solar panels degrade over timeframes that long.
It also introduces complexity, so the average cost of ownership goes up as owners must repair broken panels, deal with water intrusion from a solar panel roof having more failure points than a solid roof, pay more expensive collision repair costs and so on. The mere existence of a solar roof would increase cost of ownership significantly.
Solar panels to charge EVs just doesn’t make engineering sense.
Not to mention the rest of the car.
The main use case for this would be something like driving an EV across a desert or some backcountry well outside civilization I guess, otherwise it's probably easier to just find an electric socket somewhere.
I mean, the math isn’t hard. 200W out of a panel (at best), multiple by 5 hours to get a kilowatt hour. How many of those do you need to get back to civilization? Our Leaf gets 4 miles per kWh. The hypothetical desert overland vehicle probably gets half that.
You’re better off bring extra water and walking back for help if it comes to it.
Assuming say 60% of a 2m * 4m vehicle + some side panels @ 22% efficiency. You might get 6 hours * 220w/m2 * 2 * 4 * 60% = 6.3kWh that’s 25 miles at highway speeds and a fair bit more when your doing the equivalent of hypermiling.
I don’t see anyone trying to overland an EV but people do occasionally mess up and run out of gas on roads in the middle of nowhere.
It is my estimate of what will fit on a passenger car. I could only squeeze 410W on the roof of a 26’ RV. I doubt your 450W panel is going to fit even on something like a Land Cruiser.
And “side panels”? Ignoring the impracticality and inefficiency, no one with taste will be driving that. :-)
Besides, if you run out of juice, and if AAA will come get me in the Yukon 180 miles from Whitehorse (flat tire on the bike I couldn't fix), meaning 180 miles from anywhere, then they'll come charge your car anywhere in Wyoming. A AAA card is lot cheaper and more practical silly solar panels.
Of note, flexible panels are easy to install but have worse power output per square meter.
For 8m2 that's 911 kWh. So at an average 2.5 kWh per day.
I guess 6.3 kWh a summer day is not unrealistic.
(I thought your number was way too high but it seems to check out ...)
0. https://www.roadandtrack.com/news/a41978716/2023-toyota-priu...
From what I remember it would periodically turn on the vents to circulate air when in full sun. Also had a button on the remote to startup the AC, which only worked within remote range.
Both features did make the cabin relatively cooler after being in the sun for a few hours. This was moderately useful in Southern California.
At the time reading about why it wouldn't trickle charge the battery had something to do with radio interference, which I feel was just an excuse to avoid hooking up a proper charging system. Doubt it would have made much of a difference anyway.
Stepping into a new car that’s been sitting in the sun can’t be healthy.
I just wish parked vehicles could automatically crack the windows open, but shut them if it’s raining/snowing.
Maybe some geo-fencing so it only does it in relatively “safe” locations.
Would also be beneficial in cold weather climates: it’s colder at night, so it would be warmer when I enter in the morning if it let the warmer morning air in.
1. https://www.tesla.com/ownersmanual/model3/en_us/GUID-4F3599A...
It seems to have been dropped in the model refresh, I can't see it in any of the exterior photos and it's not mentioned in the 2022 owner's manual.
Parking in full sun in an area with significant solar power isn’t something Everyone does, but for those who do a solar car could average 5kWh per day at 20+c/kWh for electricity and more for fast charging that’s ~1$/ day of electricity and 3600$ over 10 years. However EV’s can have significant discharge when parked, being able to trickle charge enough to offset this is worth vastly more than the value of the electricity you are supplying.
A solar powered EV isn’t a great investment, but with cars lasting 25 years the economics can work out. Especially if the car can directly use solar power and thus reduce the number of charge/discharge cycles.
PS: National average is currently 16c/kWh some states are much higher than this. Again people who have cheap electricity aren’t the target audience.
A standard perfectly installed 400W solar panel gets around 1.8 kWh a day [1]. Avg US electricity costs are 16c/kWh [2]. I think you vastly overstated the above.
So some may get better, but ~half of people will get worse. So I'd guess this is actually under $0.30/day.
>1$/ day of electricity and 3600$ over 10 years.
... i.e., if you park in perfect sun all day, every day, and there's no weather or seasonal changes, i.e., this is not possible. Picking a daily perfect value and assuming that value scales to all days is not a good estimate. Maybe, if someone is quite diligent and lucky, they will get 1/2 of the perfect value over time.
So I'm at $0.30 per day at best, avg maybe $0.15 per day over 10 years, i.e., under $550 for 10 years. And of course now your solar panels are slightly degreaded, slightly less power generated, and, if you're lucky, you might get another 10 years out of them (they're on a car after all).
So for a price of $2000, up front, for 20 years, you get $1k return. Of course, if you invested that $2K at 5% over 20 years you have $5300.
So, not even close to being a good value.
[1] https://www.solar.com/learn/how-much-energy-does-a-solar-pan... [2] https://www.bls.gov/regions/midwest/data/averageenergyprices...
Also, Mount Signal Solar had a 29.7%(average 2015–2017) capacity factor from it’s solar panels. That’s averaging 2.85kWh per day across multiple years from a single 400W panel. https://en.wikipedia.org/wiki/Mount_Signal_Solar
Obviously most cars would never approach that but buyers are going to self select for better areas. How effective this would be in Alaska is irrelevant if nobody buys it in Alaska. California has both lots of sun, high electricity prices, and many people parking outside of shade. Hawaii doesn’t get quite as much sun, but is paying 45.4c/kWh right now.
Because a 400W solar panel is basically the size of a car (~1mX2m). And under IDEAL CONDITIONS, you're looking at a 150 to 250 hour charge [1] ... and you're not going to get ideal conditions most of the time.
Maybe you can stick 5 of those panels on a trailer and have the EV haul that around, and now you've improved your charging time from 250 hours to 50 hours (still, under ideal conditions) ... congrats, you still made negligible difference in extending EV range or making it practical.
>Cars are large 3D objects, you aren’t going to get nearly as much power from side panels or the dashboard as the roof ...
You're guaranteed to get 0 power from the sides that aren't facing the sun. So now you're horribly complicating the manufacturing process and increasing the EV price, all for an approach that would provide, at best, miniscule improvement to range.
>How effective this would be in Alaska is irrelevant if nobody buys it in Alaska.
It won't work in California either.
But let's try something else ... with EV manufacturers being obsessed with squeezing out every km of range, why do you think approximately 0 of them are actually building an EV with built-in solar panels? What do you know, that they don't?
[1] Assuming a 60kWh-100kWh battery and dividing by 400W = 150h to 250h
RVs are often parked in full sun at least, but even then. I think I'd be lucky to get more than 5kwhh a day. Which is great for me as long as I'm not running the ACs. But that would not even remotely account for the extra drag it put on an EV to trailer it ten miles.
There've been attempts to make "solar paint" for cars, which would be lovely if possible, but even then I think the economic argument will essentially never work out when you factor in time value of money. As the original article said, the economics will likely always be much better for putting the solar panels on your house and charging at home.
Here’s a random 2.6 kW example which still has a great deal of wasted space. https://youtu.be/Ekoh_QhiJJI
5th wheel with 3kW and still a significant amount of wasted space. https://youtu.be/BPTfkocNEu4
Did you watch that video? The solar panels are not even able to fully handle their appliances and AC, and they still use a generator to supplement. They aren't used for charging a car battery at all.
>but this discussion is about what happens if you optimize the vehicle for solar at the design phase
It still doesn't change the equation because you're not looking at a order of magnitude difference. In the case of RVs and the YouTube videos you posted, you don't need to worry about what happens if you 'optimize' a vehicle for solar during a design phase - just do a back-of-the-napkin calculation by doubling the output and ... nothing changes. The challenges are the same. The use-cases are still the same (namely, hope for sunny days to generate power to run some appliances). You're still not making any meaningful progress towards extending EV range - and that's assuming double output (and you're not going to get double in the real world).
Clearly a camper that people live in has different demands for things like AC and a microwave than a car that’s just sitting around empty most of the day. A 15.5 foot long car is half the length and nearly the same with so downscaling a 3kW system to ~1kW seems perfectly reasonable.
Toyota built a demo by sticking solar panels on a stock Prius and says it added roughly 25 miles per day of range. That would cover the majority of what the average American drives per year. Yes most people would still need to charge their cars, but suddenly using a normal outlet at home rather than paying for a level 2 charger looks reasonable. So not only are you saving on electricity but also instillation costs.
I'm not sure where I've said that because I'm not against solar panels on campers or solar panels in general. Solar panels make a lot of sense in a lot situations. For example, I don't think it's a bad idea for an RV that is frequently off-grid to have them built-in to provide whatever power they can - after all, some power is better than no power. Solar panels on outside parking lots, that makes a ton of sense to me.
Solar panels for EV range extension does not make any sense.
>Toyota built a demo by sticking solar panels on a stock Prius and says it added roughly 25 miles per day of range.
Again, this is under ideal conditions, and it wasn't meant for range extension[0] (i.e. to charge the car while it's moving). But let's go with that for argument's sake .. so you're looking at a day of charging for 25 miles of range. 25 miles is approximately a 30 mins charge connected to the grid. That makes no sense. If you really want to use solar to power your EV just get regular rooftop solar and charge your car from your mains.
[0]https://www.torquenews.com/8113/toyota-prius-solar-game-chan...
And as the original article points out, when Toyota says they add 25 miles per day, they are doing so under nothing even remotely like real world conditions. They’re surely counting on full sun, flat driving with no air conditioning running, etc. An actual user likely wouldn’t even get half of that.
Also, you can approximate aerodynamic curves with multiple flat segments, current cars with a solar roof have then installed in a survey body segment.
Uh huh. Do you want to put some numbers behind your assumptions. How much do you actually think you can generate that would make a difference to a Tesla 60kWh-100kWh battery? How much extra range do you think solar panels would provide?
And finally, what aren't EV manufacturers seeing that you are seeing? It's not like solar panels on an EV are such a novel idea. In fact, it's the very first (naive) idea that everyone has as a potential solution to EV range and charging.
So, assuming 4miles per kWh that Prius was expected to hit over 6kWh per day. That might not look like much vs a 100kWh battery pack but it’s 9,000 miles per year when the majority of Americans are only driving 13,000 or less.
Their design doesn’t look practical, but 5kW/day in sunny areas seem to be a reasonable real world goal.
I checked your link after reading your math, above. Coming from the RV solar world I found these numbers surprising. I think your comment about the 100 kWh battery pack is what threw me off. The normal battery in a Prius is 8.8 kWh with a 25 mile all-electric range [0].
Toyota is saying that the panels they used generate approximately 860 watts of power. The normal rule of thumb in the RV world (which I am familiar with) is to multiply panel wattage by 5 for watt-hours per day in good sun, so I would assume 5 kWh total per day for 860 watts of panels, in real life. So their numbers look optimistic to me, but aren't crazy - I would have said 15 miles under ideal conditions (5 kWh of their 8.8 kWh 25 mile battery), they said 44.5 km. They used 34% efficient panels to get that many watts from the limited space available on a car, something normally only available to the likes of NASA at this time (normal panels are around 20%).
Only people in places like Arizona and Texas would get most of that power output, others not so much. I don't think people realize how much impact clouds, shade and optimal panel angle towards the sun have on solar power output. Even partial shade, like form a sign post, greatly diminishes power generation, unless you want to wire the panels differently and loose early/late/cloudy power capacity.
For example, in 2021 Germany had 58728 MW of solar panels generating 49011 GW of power per year [1], which is 134.2 GW per day, which is only 2.3 times their panel capacity, and this is due to clouds. Based on this math that solar prius car in Germany may only get 5.6 miles per day of extra solar powered range with 860 watts of panels (860 watts times 2.3 is 2 kWh, or 22.5% of a 8.8 kWh 25 mile battery), or about 2050 miles per year, and perhaps a good bit less because the car panels are not oriented towards the sun like fixed panel installations usually are, and people park in shade under trees, or partial shade near telephone poles, or next to buildings sometimes, or winter when it's below freezing and cloudy the battery needs to warm itself to safely be charged, etc.
The only other thing I would add to this discussion is that panels fixed to the surface of a car may have problems with heat. Normal rigid solar panels are in frames and elevated, allowing air to flow under the panels and cool them. Panels loose efficiency with heat. Flexible solar panels, which don't need a frame and can be attached to curved surfaces, typically fail in a year or three, they are nowhere near as reliable as rigid panels. There's a lot of discussion about this in the RV and boating communities.
If the numbers work out on this idea, then that's great. Reliability would be my biggest concern, these panels need to last to pay for themselves.
[0] https://getjerry.com/car-repair/toyota-prius-plug-in-hybrid-...
[1] https://en.wikipedia.org/wiki/Solar_power_in_Germany#Generat...
You mean in 2019.
>or dashboard which they say adds 25miles of range per day.
They made a prototype. They didn't say how much extra cost it would add to the car (and how it affects reliability, maintenance and safety). The cost of those panels has to be balanced by the fact that 25 miles is 30-60 min charge from your mains vs a day of charging from solar?
They also made a point to state this wasn't for range extension - i.e. when you're driving, that solar panel isn't contributing meaningfully to your range.
>Their design doesn’t look practical, but 5kW/day in sunny areas seem to be a reasonable real world goal.
You and I have different definition of 'reasonable'. Like I said, there's a cost to putting these panels on the car and the benefit is so effin small (even sunny areas have cloudy days and/or your car is frequently parked in the shade or indoors) that it's much more reasonable just to plug the darn thing into your mains and charge that way.
Did you bother looking up panel sizes? One large panel (5.4'x3.25') is most of usable car area. Sure, maybe you can put 2 or 3 - at vastly lower return due to being tilted towards the sun.
Do you really think that you can get more power over the entire surface of a car, when most of it will be tilted to the sun, as you can get from an entire panel optimally placed?
Go ahead and demonstrate.
>Mount Signal Solar had a 29.7%(average 2015–2017)....
Did you bother to check any of the math?
For example, the single 400W panel is a First Solar Series 6 440W, 80"x49", that and they use trackers to make them align to perfectly to the sun. Want to estimate what you'd expect from a car? I don't think you're putting an 80 x49" large flat surface on it, unless you want to drag losses to vastly outweigh anything else. Other panels in later phases are even worse when you think they apply to cars.
I'll never understand how people think the most ideal, large scale installation at ideal location, with moving trackers, will yield the same on a car with nearly zero surface at ideal angles.
>buyers are going to self select for better areas
How well are these solar cars selling in these best places? That might give you more insight.
Solar options on EV’s will always be niche. Probably less than 20% of people would see significant benefits. However, as the percentage of EV owners increases that ratio should stay the same. 5% of EV buyers (themselves 5% of car buyers) the market isn’t very many people. However if EV’s made up 75% of new cars then 5% of that is a more significant market segment.
For now I suspect cars with an extreme focus on solar will flop. But, a base model with modest styling compromises and 2 levels of solar options roof vs every surface could be quite popular. In the short term a solar on a van seems to be the obvious option with the smallest compromise. It’s stick with large nearly flat surfaces to maximize internal volume, so why not toss in solar.
????
By approximate you mean lose signifcant energy?
A car is a closed manifold. Take the area it casts a shadow on - that is the area a solar tracker would get ~100% of the sun's flux. A general closed manifold (which is prefect for a car since the car and sun will move) will get ~50% of that energy. That's pretty massive.
A simple way to compute exactly 50% loss is for the area of a shadow from a sphere - a tracking disk with that area would get pi * r^2 of the energy. A sphere with the same shadow would get 50% of that (set up, integrate).
Do you even check these claims?
Of course you'll fixate on a sphere vs a car, but make any closed manifold, let the sun move throughout the day, and you will end up with pretty much the same result (via theorems on total curvatures on closed manifolds stuff).
I recommend sketching this out for yourself.
So go ahead and demonstrate my lack of reality. Post your panel stats and math. I did.
Have you looked at the size of solar panels per watt and the flat area available on a car?
I have solar panels on a boat and the area is approximately (don't have measurements here with me) about the size of the roof of a regular sedan. All I could fit there was 110W worth of panels. If you have a long, wide SUV you can do more but only so much more.
In practice, those 110W worth of panels really only deliver 40W-50W to the batteries on a good sunny afternoon in California. The angle isn't perfect just like it won't be on a car which reduces output quite a bit.
It's worth it on a boat because I'm only charging the batteries to power the electronics so it's borderline enough. On an EV which uses tens of kW to move, it would be a microscopic contribution.
On a car or small truck there just isn't enough sunlight to make a difference even at 100% efficiency (last I heard labs were getting in the low 40% range using tricks that probably don't apply in the real world). However for large motor homes (and possibly semi trucks) there is enough roof space to make a difference. Motorhomes often stop for a few days at a time so can get some useful range (or at least not use the batteries running the stuff inside).
In no case though is anyone thinking about saving money with solor on a moving vehicle. The large ones can possibly get enough range to be worth the extra costs even though it's costs more money.
What I'm seeing on this topic is a lot of folks that I can only assume have never spec'ed out and actually used a solar installation. Go throw some panels on the roof of your house and RV, and then we can talk about how "all we have to do" is put panels on a passenger car. Not one of the "all ya have to do" crowd has mentioned how efficient their solar installation is, how the math works. Nope, it assumes a spherical cow, yada, yada, yada, and the sun is always pointing at a direct 90 degree angle to the panel.
The 410W on our RV, for example, is good for recharging the house battery after running the microwave to make breakfast. If it's cloudy, you won't get to run the microwave for supper, but at least the lights can stay on. The most I've ever seen come out of that installation was 390W. I've not looked that hard at the charts, but I'd assume on average maybe 200W. A cloudy Seattle day? That's when we're glad we bought the bigger house battery.
With some quick-and-dirty visual estimates from the charts, I'm coming up with about .85kWh/day. Yeah, I know, but I looked at it twice. I went back and looked at some other time periods as a sanity check. And <1kWh/day is what we get. In the summer. Right now the RV is sitting in the drive with the panels uncovered, and the driveway is sloped and slightly angling the panels to that sad little January-in-Seattle sun. Yesterday the panels cranked out a massive 0.1kWh. That's right: enough to run a 100W light bulb for an hour.
Despite all that, it's enough to run the microwave a couple of times a day (which is really the only large draw the RV has), watch some TV, run the lights at night. And if the panels can't keep up, that's what the giant-ass 300ah lithium house battery is for.
[1] https://www.researchgate.net/publication/349656294_Future_Op...
> Especially if the car can directly use solar power and thus reduce the number of charge/discharge cycles.
There is no way the extra weight won't offset that.
Perpetual solar EVs look more like bikes than cars.
Solar is surprisingly lightweight the 1kW per day Hyundi solar roof was installed in a 60 lb panel. That’s slightly heavier than a steel roof, but not by that much especially compared to a 4,414 lbs. car.
Their next designs looks to be adding a solar front trunk and easily doubling output.
It's really popular because it's solar or nothing in a lot of cases. That, and those large, flat surfaces make for convenient mounting on a surface that otherwise isn't getting used. But it most certainly is not because it generates "significant amounts of power". I have to wonder how many RV and boat owners you've actually spoken with to come to that conclusion.
but for those who do a solar car could average 5kWh per day
I'm not even going to bother with doing the math to refute that, as that is laughable fantasy.
I'm not going to retain my EV for 25 years, simply because I'm expecting more innovation to happen in the EV space. But I'll be damned if I'm not buying my motor home or boat to last for at least 2 decades. That's the key difference.
Depends what you mean by significant I suppose, but unless you have tons of square footage for panels (like the whole roof of a house), you're not getting a lot of power from solar.
Have you done solar installations and tried to live off the power they generate? It all sounds great until you do the math and realize how little power you have.
I have both a boat and a travel trailer and spend occasional time living off the grid on both. You quickly learn to be very frugal on power.
> a solar car could average 5kWh per day
How much roof surface area you'd need for that? Is there a car large enough?
Only if you are choosing to park in the sun instead of parking in covered parking. That's almost never a choice your can actually make.
The real utility of solar panels would be for driving in areas that don't have utilities (places to charge) near enough to charge from. Though, in that case, it still makes more sense to carry separate panels folded in storage than to integrate them into the roof.
I wonder if the added weight of detachable panels would cancel out any benefit, though.
Biz idea: parking spot with panels as roof. You can recharge for some coins and keep the car cool.
* 30% of Europeans rent. 50% for Germany.
* 46% of Europeans live in apartments. 63% for South Korea.
It reminds me of the whole "just install a charger at home" argument. It simply isn't an option for a large percentage of the world and alternatives will be needed. Solar cars may have some impractical elements but at least it's workable.
It's like sure, in Manhattan no one has a charger at home and most people live in rentals.. but also the cars are all parked underground or street parked on shaded side streets, so....
Because it's not like the entire city is a massive Shinjuku with ultra-high density and no sunlit spaces. It is mostly open places e.g. parks, regular housing, office zones etc with concentrations of apartments in select areas.
And it doesn't address the point that 1/3 of Europe rents and can't just add solar panels.
Beyond that.. Yes Tokyo is a big sprawling city with lots of low-rise neighborhoods. However it's not like Tokyo really has street parking there either. Most of these cars are going to be underground. You need a permit in many areas of Japan certifying you have off-street parking for any car you purchase. So again, Tokyo is not like NYC where people just street park cars all over the place. That's why people complain about the urban character of US vs W Europe/Japan/etc.. most of those places don't have the "car culture" of America.
You don't even need to add solar panels. Just being within 50ft of a 110V outlet one night a week is going to get you as much charge as these solar roof pipe dreams.
There's a reason basically none of these have gone to market and the startups proposing them are either bankrupt or on the verge of it..
A very large part of the parking space in the city is underground. Almost all housing with parking space have it built under the building. Here "regular housing" is apartment buildings and there are only a few smaller areas with single-family houses.
Most recent shopping malls have underground parking too. Only a handful have open surface level parking and that's the ones outside the city. Not just shopping malls, the trend for smaller supermarkets currently being built is having inside parking. As for parks... most just don't have any parking space. The two or three that do, it is indeed open surface level parking. But most parks in the city just don't have parking space. You walk there or take public transport.
There is, sure, parking in the street. And this is generally a sunny city, as I said. And yet, a large part of street parking space available is under tree shade and/or under a building's shade for most of the day. A street where you can park and that is wide enough to get more sun will very likely have trees planted.
So... yes, there is a lot of sun here, there's no discussing that. But the city is just not built to let parked cars get those sun rays.
----
On the other hand, yes, it's not feasible for a large part of the population to put solar panels up at home. That is undeniable. Some companies are trying to come at this from a different angle: they are promoting installing solar panels as a shared resource for the whole building. The downside is that usually you don't use it, but just sell it back to the network. But it does produce an extra source which, at the end of the day, is what counts. It may not be the best solution, but it's what you can do.
I assume you have a specific city in mind where this is the case.
It must be a fascinating place given most of the public is living in perpetual shade.
And this hasn't happened already because ..
I am going to take an educated guess that your views do not align with the majority of Europeans.
[1] https://www.statista.com/outlook/mmo/passenger-cars/europe
The statement was not 'market for cars is zero'. The statememt was " public transport and bikes will do most of heavy lifting". its expressed in passenger-miles, not $$$. Looking at $$$ does not consider efficiency.
If you wanted to look at $$, what is the size of public transport budgets, markets for tickets and bikes?
Because the European car market (which is larger than the US) needs EV options. And those options will need to factor in the conditions in those countries namely that there is a comparatively higher number of people renting and in apartments.
Car markers clearly understand the problem and the opportunities here.
Even if I've got a house, the car will be parked in a garage or under the roof, no (solar) charging there. Solar panels on the house roof are a whole different story.
However, if we simply reduce the hyperbole "next to impossible" to something like "uneconomic" or "inconvenient" then we are getting closer to the truth. The only exception which MIGHT be somewhat close to impossible is Freiburg which is comparatively restrictive towards cars. Its population consists largely of economically weak students though, so it fits the crowd.
Taking the car to commute to the very center of cities is an economically senseless thing to do in large urban areas in Germany unless your commute is from the outside of the city. Public transport and bike infrastrucutre is mostly good enough for most people despite large room for improvement, especially when looking at Netherlands or Denmark for comparison.
This is also something that is VASTLY different from American ways of providing mobility, the situation is not comparable at all due to the average commute distances involved which are orders of magnitude higher in the US.
"Next to impossible" comes from the traffic and how expensive (along how lacking) the parking in city centers is. I have lived in 4 different European counties and visited almost all of them. Germany wise (not lived) - I'd not consider Frankfurt, Berlin, Stuttgart or Munich a place I'd like to drive to work every day. Dusseldorf was better, but still. Many EU capitals are pretty much hell just to drive through - I am hard pressed to say, "yay this one was ok".
Most of the larger cities are just not designed to the amount of cars there are - the roads are relatively narrow too. (Also the parallels to the US are funny - I have lived all my life in Europe, visited the USA but that's all)
It's less of an opportunity to make money, so its not talked about as much.
Hyper ~ money mwking opportunity. if it improves your life, but isn't a money opportunity, thete is no hype.
It’s strange there’s nothing in between roof top solar for your whole house and a dinky panel built into your car roof.
Also what about if we also put solar panels in front of the the headlights so we can charge the car in the dark? /s
https://m.youtube.com/watch?v=jyQwgBAaBag
Also a 500W panel is ~ 20 KG (~45 pounds) and an MPPT can exceed that weight. For a car with a battery that is tens of KW, any portable system that is less than a few KW is not very useful, charging the car 5% per day is not feasible for most.
You can simply get a ground based solar install at your home if you can't install on your roof. But really $1000-4000 does not buy nearly as much solar as you are assuming. Go google "off grid solar kits".
You are better off hooking that up to your home than your car, as the hours it is generating power your car may not be home. If you add a battery to try and solve that problem, the battery will consume 90% of your budget. Don't forget there are fixed costs like the charge controller, and any electrical work to tie the solar array to your home. So your fixed costs alone are in the $1000-3000 range.
Not everyone has reliable access to charging.
This could be added to a plug in hybrid (mine only gets 20 miles electric, which covers my summer commute).
Should solar panels be added to every electric car? No.
Could this be an option for some people to reduce dependency on gas who are otherwise unable? Maybe.
https://aptera.us/vehicle/
Pointing to Aptera as an example of why this is feasible is like pointing go some screen grabs of Duke Nukem Forever in 1999.
Solar roof cars are like the Google Glass of EVs.
Higher interest rates makes a highly efficient and modestly sized two seater more attractive not less.
But higher interest rates are bad for startups with no revenue, who rely on venture capital to avoid bankruptcy.
That said: 1. VCs say a lot of things, and don't always put their money where they say they do. 2. It's troubling that aptera is going for even more equity crowdfunding, and that they are throwing a lot of their fanatical (first mover) supporters under the bus by preference exclusively to crowdfund investors, it's a sign of desperation.
Lots of EV companies were high on cash and most still couldn't get a car into production.
Trying to do it now where it is way, way harder to raise massive amounts of cash is incredibly hard. And this start-up has already gone bust once, and are trying to bring a vehicle to market that is quite complex and has limited appeal.
First it actually costs money to scale production as you point out.
On the consumer side it now actually costs money to buy a car. No more 8 year loans at 2.5%. Consumers are price sensitive again.
If you have kids, or a ton of stuff you need to carry I would recommend a Prius Prime instead.
A single car parking spot worth of canopy could maybe generate 20kWh per day being very very optimistic... meanwhile L3 charging users pull down 20Kwh in about 8 minutes of charging.
It offers shelter, prevents the car from overheating, distributes resiliency where people need it, reduces the dependency on electricity transport infrastructure, answers the annoying question about the fossil-fuel-dependent grid, etc.
But I agree: you don’t want just the loading section, but every parking lot to be entirely covered, resting area, play pen and access road too. Mainly because those are available areas that could use the shelter and, if anything, for more marketing: brand the panels to make the fast chargers in the corner of the parking lot that much more apparent.
I actually would rather have a (slow) charger at every spot in that lot, to tell all car users: if you had an electric car, you could fill up while you shop. No need for the big fast one.
More so: even then, you are still right that we need more. Have agri-voltaic near the fast chargers to show people how those work, or non-polluting industry that need large amount of electricity: Hydrogen generation maybe? It would reduce the dependency on infrastructure. It would be striking to have people take a break from the road near modern installations that demonstrate that we can have less polluting options.
Better to put all of them in a big field. Easier, safer, and cheaper to install and maintain.
If the grid is fully modernized and using 99% renewables, there are very few reasons to want photovoltaic panels on cars. So you focus on what's cheap and scalable.
Keep the inside cool if left in the sun without draining the battery.
Designing a car is not a hurdle.
Building a prototype is not a hurdle.
Having 20k pre-sales is not a hurdle.
Actual serial production in an operational factory able to ship 10k+ year is your first hurdle.
Doing the above while selling the cars for enough money to not go bankrupt, while opening some sort of service network for the cars .. is a big hurdle.
Getting closer to 100K/year, is the next real hurdle.
And being a real big boy automaker in the 1M/year range is
The founders went on to other things for a few years. Now they seem to be making pretty solid progress. I don't think putting "trying" in scare quotes is justified; launching a car company isn't an easy task.
They have a strong commitment to the community and are transparent and publish regular reports and insights to their progress. They also take a open-source aproach to maintenance, basically releasing everything you (or your local repair shop) need to fix things, and they try to choose readily available parts when possible.
[0] https://sonomotors.com/
I know, because I put solar panels on an ICE car's roof several years ago. They charged a recreation battery in the boot, which I used to charge my phone, headlamp, camp lights, laptop, radio, smaller power bricks...
Fantastic for camping, and it lets you jump-start your own car.
The article's prices are for first-party solutions; I paid $2/W and it's been zero maintenance over highways, bumpy tracks, heat, car washes, and frost. Using amorphous cells instead of monocrystalline can net you a bit of energy on cloud/rainy days too, even if they are less efficient in bright sunlight.
If you have roof rails or a pickup canopy, give it a try. The hardest part is finding a way to get the wires into the interior. Don't forget some soft cushioning washers in the mounting nuts and bolts.
I also had a 100W Panel on the vehicle I just drove around Australia for 18 months.
In both cases, I'd say they were essential
[1] theroadchoseme.com/the-jeep
I’m not sure why the boxer van market isn’t the most obvious candidate, both for delivery companies (extending an otherwise relatively short radius and lowering the cost of battery seem well aligned) and camper-van, where the autonomy sounds worth the cost. Big rigs also feel like the perfect candidate, assuming someone can figure out how to attach panels when the load is detachable.
Trains are fantastic options, although not as perfect as having panels along the rails. Airplanes, even more so — although, yes, integrating into the structure isn’t a done deal.
Rickshaws are another obvious example: they can run without pedaling if the whole roof is a solar panel. There’s also a more accessible version of a bike for road trips that could leverage the bicycle-with-a-roof format well.
Boats are surprisingly appropriate candidates. Leisure boats, in particular, are mainly used when it's sunny. The water offers extensive cooling available. There are electric waterboards that might not have a roof but still have enough surface to be promising—although I think a new format, akin to a wind- or kite-surf, might make more sense.
Too much of the logic starts with assuming people are driving a sedan or an SUV. That’s a terrible idea. It already kills millions every year. We can’t let that lack of imagination also kill electrification.
Perform studies, get real numbers, otherwise, you're just going to get a bunch of disappointed customers.
Having to think about where to park my car to maximize my range is only going to add to EV range anxiety (not lessen it) if you don't have a reliable place to charge.
That sounds like a shortcoming of implementation, not proof that the concept is bad. Yes, I'm suggesting that cars with solar panels should have tilting, sun-tracking roofs.
Not that it matters. The reason cars do or do not come from the factory with solar roofs is sales. If the market pays for it, it stays. If they don't, then it goes.
I've seen countless people pay thousands of dollars for "ground effects" which are nothing but painted plastic glued and/or screwed to the car body, chrome packages, blackout packages, and 'leather' seats that are actually vinyl and less comfortable than cloth. A significant portion of the automotive market is driven by aesthetics, misinformation (e.g. 'leather' seats), and consumer fantasy. How many dudes driving huge diesel trucks do you see actually towing heavy loads or picking up shipments at a loading dock? This is just the green version of the same fantasy marketing.
Incidentally, I would love a solar roof if only to power a fan to keep air circulating when I have to park in the sun, and to trickle-charge the battery when I'm away on vacation. Not everything has to be an ideal solution to powering transportation.
Having a solar panel won't save much money, but at least you can drive a bit every few days during a major power outage. Something that's becoming more of an issue as infrastructure becomes less reliable.
[1] https://teslamotorsclub.com/tmc/threads/battery-drain-while-...