Solar panels on cars make no sense at this point

https://www.arenaev.com/why_solar_panels_on_cars_are_beyond_stupid_at_this_point-news-1295.php

by elorant • 3 years ago

101 241 3 years ago

bilsbie3• 3 years ago

I agree but not completely.

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.

sclarisse2• 3 years ago

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.

bilsbie3• 3 years ago

Cell phone reception is actually pretty spotty once you leave urban areas. So it could be more frequent than you’d think.

And beyond that it’s harder to call for a charge up than for a can of gas. So options might also be limited.

tomrod2• 3 years ago

5 - 10 miles per day of sunshine = 1200 to 2400 miles in high sunny place, 600 to 1200 miles in low sunny place (speculating).

Not bad value add.

AdrianB14• 3 years ago

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.

steveBK12329• 3 years ago

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?).

This is not set-it-and-forget-it convenience.

myself2482• 3 years ago

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.

steveBK12329• 3 years ago

The number of people who need a car and drive less than 5 miles a day is a small circle.

Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway..

driverdan2• 3 years ago

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.

pornel• 3 years ago

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.

t3443444• 3 years ago

Solar panels make great sense on ICE vehicles. Trickle charge from small solar panel may preserve internal battery much better.

And there are RVs. Some people use solar panels on cars as their only source of electricity!

steveBK12329• 3 years ago

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.

t3443444• 3 years ago

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!

AdrianB14• 3 years ago

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.

mikestew10• 3 years ago

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.

steveBK12329• 3 years ago

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.

dev_tty01• 3 years ago

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.

Ekaros• 3 years ago

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...

wazoox• 3 years ago

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...

moffkalast4• 3 years ago

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.

bouk• 3 years ago

Lightyear zero is no longer in production: https://lightyear.one/articles/lightyear-decides-to-fully-fo...

And it seems like the whole company might be bankrupt.

mikestew10• 3 years ago

the lightyear 0 has a sophisticated series of controllers…

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...

jillesvangurp2• 3 years ago

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.

steveBK12329• 3 years ago

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.

panick21_7• 3 years ago

Aptera is also close to production.

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.

jjav4• 3 years ago

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.

steveBK12329• 3 years ago

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:

whazor• 3 years ago

It is a shame, they had a really promising car.

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.

steveBK12329• 3 years ago

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.

threeseed8• 3 years ago

Short version:

* 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.

Teever• 3 years ago

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.

powera• 3 years ago

Nope.

* 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.

steveBK12329• 3 years ago

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.

mikestew10• 3 years ago

$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.

PragmaticPulp• 3 years ago

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.

moffkalast4• 3 years ago

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.

mikestew10• 3 years ago

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.

powerbroker2• 3 years ago

And in 5% of the parking lots, where there is 0 theft going on, I'll be sure and use it.

JKCalhoun2• 3 years ago

A solar carport sounds ideal. Guessing many HOA's would lose their shit over that though.

matthewdgreen• 3 years ago

This is the one I want to build (though in a smaller size.) It’s attractive and uses panels directly as the roof. I am debating whether to get into a war with my HOA over it. https://timberhomesllc.com/our-work/outdoor-structures/vermo...

Rebelgecko• 3 years ago

Those are becoming somewhat common for big parking lots in Southern California, like at schools

coredog64• 3 years ago

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.

steveBK12329• 3 years ago

Toyota yanking the feature tells us something about the consumer uptake, cost-benefit, and ROI.

panick21_7• 3 years ago

With a modern electric car you just use your phone to turn on the AC before you get there.

agumonkey• 3 years ago

Also depending on the material, it could be a film to glide under windows, so youd avoid heating the car and getting current.

fortran77• 3 years ago

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

ecliptik• 3 years ago

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.

sbierwagen• 3 years ago

The first gen Nissan Leaf EV had a small solar panel on the roof to run a ventilation fan: https://en.m.wikipedia.org/wiki/File:Nissan_LEAF_SL_Solar_Sp...

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.

Retric11• 3 years ago

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.

SideQuark5• 3 years ago

5kWh per day at 20c/kWh

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...

brigade• 3 years ago

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]

[1] https://www.researchgate.net/publication/349656294_Future_Op...

rightbyte3• 3 years ago

Motor homes and boats use the solar panels to charge the utility batteries not doing propulsion.

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.

mikestew10• 3 years ago

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.

fakedang• 3 years ago

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.

jjav4• 3 years ago

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?

thomastjeffery• 3 years ago

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.

munchler• 3 years ago

it still makes more sense to carry separate panels folded in storage

I wonder if the added weight of detachable panels would cancel out any benefit, though.

narag• 3 years ago

Only if you are choosing to park in the sun instead of parking in covered parking.

Biz idea: parking spot with panels as roof. You can recharge for some coins and keep the car cool.

dzhiurgis• 3 years ago

“California now requires all BEV’s to have solar roof and hood with at least 27% cell efficiency” and suddenly manufacturers marginal cost is $100.

GoToRO• 3 years ago

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.

threeseed8• 3 years ago

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.

steveBK12329• 3 years ago

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....

threeseed8• 3 years ago

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.

phicoh• 3 years ago

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.

GaggiX4• 3 years ago

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.

threeseed8• 3 years ago

so it would be really hard to find a spot where a car could get significant sunlight

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.

andrepd• 3 years ago

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.

threeseed8• 3 years ago

So all of Europe, South Korea etc are going to abandon their cars in favour of public transport and e-bikes.

And this hasn't happened already because ..

ClumsyPilot2• 3 years ago

big proponent of ebikes, they are sold in millioms and are making a bigfer difference than electric trucs, cars and planes at this point.

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.

sollewitt• 3 years ago

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.

bilsbie3• 3 years ago

How come no one is building a portable EV Charging kit with a bunch of panels you can spread around the area. Maybe in the 1000-4000$ range.

It’s strange there’s nothing in between roof top solar for your whole house and a dinky panel built into your car roof.

JKCalhoun2• 3 years ago

I imagine those would get swiped pretty fast.

driverdan2• 3 years ago

Because it doesn't make any sense. No one is going to put up and take down a giant solar panel array to charge their car.

steveBK12329• 3 years ago

Yeah but what about a wind vane that deploys from my car roof to re-charge my battery while I am driving? /s

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

AdrianB14• 3 years ago

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.

steveBK12329• 3 years ago

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.

tbrownaw• 3 years ago

That sounds less like a car-related thing and more like a general-purpose "here's a solar-powered standard electric outlet".

Forge362• 3 years ago

Not everyone parks indoors.

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.

thomaslangston2• 3 years ago

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.

https://aptera.us/vehicle/

steveBK12329• 3 years ago

Aptera is not long for this world, especially now that ZIRP is over.

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.

thomaslangston2• 3 years ago

This doesn't compute.

Higher interest rates makes a highly efficient and modestly sized two seater more attractive not less.

incone123• 3 years ago

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.

ianai2• 3 years ago

Yes they need to make a four wheel option that doesn’t look like a great way to die in any accident for those of us surrounded by F150s and larger.

cagenut• 3 years ago

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.

timbit422• 3 years ago

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

twobitshifter3• 3 years ago

How big is Aptera’s trunk? https://m.youtube.com/watch?v=f3jVDqiLYOs

foxyv• 3 years ago

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.

freitzkriesler• 3 years ago

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.

tappaseater• 3 years ago

Even solar panels over a bank of Superchargers is essentially a marketing exercise. An array over a 20 acre parking lot? Now you're talking.

steveBK12329• 3 years ago

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.

bertil2• 3 years ago

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.

googlryas• 3 years ago

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.

TillE• 3 years ago

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.

Schroedingersat3• 3 years ago

Here's one of many reasons:

Keep the inside cool if left in the sun without draining the battery.

powerbroker2• 3 years ago

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).

steveBK12329• 3 years ago

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

DennisP• 3 years ago

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.

DueDilligence• 3 years ago

.. sounds like fossil fuel propaganda to me .. yawn. next.

rsolva2• 3 years ago

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.

[0] https://sonomotors.com/

florakel• 3 years ago

At this stage it looks very unlikely this car will ever make it to production. They ran out of money and try to save the program through crowdfunding https://electrek.co/2023/01/26/the-future-of-solar-evs-dims/

rsolva2• 3 years ago

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.

legulere• 3 years ago

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.

reeckoh• 3 years ago

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.

grecy3• 3 years ago

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.

In both cases, I'd say they were essential

[1] theroadchoseme.com/the-jeep

bertil2• 3 years ago

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.

ajross• 3 years ago

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.

dredmorbius2• 3 years ago

Or just connect that PV array to the overall grid and supply / request surplus / deficit power as needed.

turtlebits• 3 years ago

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.

egberts12• 3 years ago

This solar panels on vehicles would make most sense in Sahara, Gobi, and Outback.

snozolli• 3 years ago

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.

Animats• 3 years ago

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.

[1] https://teslamotorsclub.com/tmc/threads/battery-drain-while-...

standardUser• 3 years ago

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.

college_physics• 3 years ago

Solar panels on parking lots seems to be significantly more beneficial. A true value enhancing function for vast areas that go substantially underutilized. The installation can be optimized, will cover significantly larger area, collect irrespectively of number of cars parked and protect the cars underneath.

Cant think of significant downsides besides vandalism/theft

zackmorris• 3 years ago

Another vote from me: this article is nonsense and I don't think that HN's readership should endorse this kind of propaganda. Evidence (no affiliation):

* Solar panels are approaching 50 cents per watt: https://www.altestore.com/store/solar-panels/vikram-solar-54...

* 700 watt panels are going mainstream: https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel...

* 240 V inverters are approaching 10 cents per watt (and wouldn't be needed at all if EVs accepted direct DC input like CHAdeMO and CCS to charge while driving): https://invertersrus.com/product-category/power-inverters/24...

The future is solar cars that charge themselves while sitting idle, that power the home through bidirectional charging off the shelf:

https://driveteslacanada.ca/news/ontario-man-uses-ford-f-150...

This was all set to be rolled out in the early 2000s had the Bush/Gore election been decided differently and the entire weight of the industrialized world's moneyed interests hadn't decided to crush EVs. See Who Killed the Electric Car and similar for overwhelming evidence of this.

Thankfully it's no longer their choice. We can build our own solar-electric vehicles now. In fact, I bought 2 panels and was in the process of building a roof rack and 5-10 kWh buffer battery to sit in the trunk of my 2013 Nissan Leaf before the economy conveniently shrank to vacuum up any available money for such projects.

Edit: this sure didn't help either: https://time.com/5113472/donald-trump-solar-panel-tariff/

kibwen• 3 years ago

Right, for a light passenger vehicle (smaller than a sedan, larger than a motorcycle) you can probably get 40 miles of range per day if you live in a sunny locale. That ain't road trip mileage, and it may not be economical depending on other factors, but for lots of people that would be enough.

Neil44• 3 years ago

Really? If it’s incredibly efficient at 4mi/kWh you’d need 10kwh per day (assuming 100% efficiency) from a panel on a car roof… that doesn’t even seem close to me.

Scoundreller3• 3 years ago

Edit: this sure didn't help either: https://time.com/5113472/donald-trump-solar-panel-tariff/

Can’t you just hit up Mexico or Canada? I thought Americans can bring in US$800 duty-free at a time.

I guess you’d lose other subsidies though.

jjav4• 3 years ago

700 watt panels are going mainstream: https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel...

That panel is just under 8ft by just over 4ft. So basically same size as a sheet of plywood, i.e. the size of the bed of a long-bed pickup truck.

That's not going to fit on the roof of most cars.

Schroedingersat3• 3 years ago

Split it into quarter cell tiles and it fits easily on the roof, boot, and hood. Then there's the sides which produce a significant amount of power in any orientation unless you're right on the equator.

Overtonwindow• 3 years ago

If it ever comes to fruition, the car Aptera is able to achieve 50 miles of range on eight hours of sunlight. We don't have a garage, so I think that would be amazing to let the car sit outside in the sun and recharge rather than plugging it in. At this point, I think anything that we can do to improve the efficiency and energy generation for electric vehicles makes sense.

grammers• 3 years ago

Of course, it doesn't. Putting them on balconies also doesn't make sense - at least if you look at the bigger picture. The panels should be perfectly positioned to get the most out of it. Otherwise, it's simply a waste producing them - which also costs energy, resources, etc.

Schroedingersat3• 3 years ago

EPBT is 4 months in excellent conditions.

A south facing facade in northern scotland is about a quarter of this and can gather about 0.4kWh/day/m^2 epbt is still well under 3 years.

A 2-3 bedroom apartment has about 7-14m^2 of non-window 4kWh/day isn't going to cover everything but it's decidedly not nothing.

Kim_Bruning• 3 years ago

Maybe not on current crop of consumer cars, but solar powered cars are definitely a thing.

https://www.tue.nl/en/news/news-overview/solar-car-tue-wins-...

rcxdude• 3 years ago

These are heavily optimised race cars, not practical production vehicles. (the WSC has being going for a long time and is a great engineering challenge but you're never going to see something similar to these cars on the mass market).

grecy3• 3 years ago

How about a trailer for the Tesla semi that is covered in panels (top and sides) and has just enough battery so that after about ~10 days sitting in the sun it's full. You plug it into the semi to charge it, and of course it charges it's internal battery while you're driving. A trucking company could just have 10 on them on rotation, so each day it's using a "full" one while the others charge

Obviously we're not getting a ton of range, but free range is free range.

dredmorbius2• 3 years ago

As with virtually every other suggestion for solar-on-vehicle for actual mobility (not house / auxiliary services): the idea becomes vastly more sensible and practical when you separate the mobile and cPV components.

A battery trailer that can be coupled to a vehicle is a reasonable suggestion. I've made it myself.

But for charging that battery ... you're far better off putting the PV in a fixed location well-suited to solar power, rather than on the mobile vehicle itself where the array is not usable whilst the vehicle is in motion, the hard-coupling means that the battery itself only affords a 10% duty cycle (as opposed to something closer to 30-50% if charged off-vehicle from mains), is subject to road wear (vibration, shock, collisions, debris), and adds significant mass to a moving vehicle (which reduces overall efficiency).

Better yet: have that PV be part of the overall power grid so that when you don't need it to specifically charge vehicle batteries, it can serve other electrical needs.

Yes, of course, if you're looking at a location that is off-grid and has little local electrical infrastructure it's possible that some fully-self-contained solution works. We do put PV on satellites and spacecraft, or on (usually small, low-draw) remote applications ... because it's difficult to run extension cords to Earth (or interplanetary) orbits, and running dedicated grid across 1,000s of km of wilderness for a single use is expensive.

But again, we have other options here as well, including fuel-based power systems, radioisotope thermal generators (RTGs, for both terrestrial and space use), and possibly even small on-site next-gen nuclear plants (though I've ... concerns here, they are a serious proposal however).

The real lesson on solar-powered vehicles (automobiles, lorries, ships, aircraft) is that the power density and available solar flux are simply very poorly matched. There are reasons why fuel-based prime movers were so widely adopted, and that in their stead, typical alternatives include electrified routes (for rail, and some barge traffic), or wind (the traditional option for moving ocean cargo).

Direct-solar electrified transport will be at best limited, or limited to small, slow, and exceptionally light-weighted, mostly-autonomous vehicles rather than passenger or cargo services.

grecy3• 3 years ago

Not true at all.

These people [1] are driving the length of West Africa charging their EV exclusively from fold-out solar panels.

In one post they said they gained about 250km (156mi) in a single day of charging.

Here's how all their panels look laid out in the sun [2]

[1] https://www.instagram.com/4x4electric/

[2] https://www.instagram.com/p/CmoD0iJom10/?hl=en

CephalopodMD• 3 years ago

As a person who lives in SF, doesn't have a garage, owns a model 3, and uses outdoor street parking, I have to disagree. The convenience of not having to periodically go to a charging station and pay a major premium for that electricity might be well worth it.

Where I usually park, it's sunny 90% of the time, not too hot, and mostly unshaded. This sounds pretty close to optimal, so according to the article I could probably expect to be topped off most of the time with a good panel setup.

I probably drive around 50 miles a week (not counting longer road trips) and lose charge while parked as well. Accordingly I charge up once every 2 weeks or so for about $15-20. That's about $400 a year. Not even accounting for the help on longer road trips, that makes things financially worth it in just 4-6 years for me. That's not even to mention how much more convenient and time saving it could be.

I think the thing that would have me most concerned is the possibility of having my car broken into and losing the panels to theft... So probably a pipe dream for now.

num3ric• 3 years ago

Author: who lives in an apartment anyway?

amarant• 3 years ago

The reason solar on your car doesn't make sense is because the extra weight will end up costing you more energy than it brings. You simply don't get enough area on a car for the charge generated to be in any way significant. The extra couple of kgs won't use much extra energy to lug around either, but unless you drive very very little, it's likely to be a net loss in the end.

Even ignoring any risk of theft, it's not worth it.

nelsonenzo• 3 years ago

Wrong conclusion.

The problem here they are charging $2,000 for a $200 panel.

I do not believe it adds much more to the manufacturing as the raw cost + sunk cost of automated design.

Also, I live in Vegas and am usually parked in direct sun, almost all of his arguments are completely mute in most of south west US, and Australia. Yeah, totally agreed it's a stupid option in high density foggy London. Author needs to travel a bit, IMHO

grobbyy• 3 years ago

To me, the major upside is lower risk of fully dead in the water.

Yes, I understand the top speed might be 5mph, or I might need to wait a day or two before driving, but in an emergency, that's a lot better than a dead car

fwungy• 3 years ago

I have portable panels with my Jackery. Two hundred watt panels would be the max a normal car could handle.

Then you have to park in a place with optimal sun exposure to max out. Even at max, that's only enough power for hvac, and it won't be great in long cold Winters.

Its probably more efficient to spend the panel money on a slightly larger battery.

ZeroGravitas• 3 years ago

The main problem for PV on vehicles is that electricity, anywhere that PV works, is about to become very cheap. So it's effectively outcompeted itself. The further advances of rapid and wireless charging and batteries are also undercutting the need.

PV is going to end up everywhere though. It'll be cheap enough to build into all windows and building facades. So it'll be on most vehicles too.

Solar panels on cars make no sense at this point

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