As a back of the envelope calculation, if you covered the ~2.44 m2 roof of a VW ID3 with solar panels you'd probably see somewhere in the region of 244 kWh / year (based on typical UK solar panel generation per year - this would be more in a sunny place). At 4.3 miles/kWh that gives you just over 1000 miles / year of self charged driving.

It's true that those same solar panels would be more productive in a static installation. But it's also the case in the west that the biggest cost to solar rollout is installation, not the panels themselves. Putting panels on the roof of a car can be done in a factory, with none of the tricky site-specific work that makes costs balloon.

In fact, Hyundai are already planning a solar roof option with their Ioniq 5 (https://interestingengineering.com/hyundai-unveils-charger-o...). It will be interesting to see if that has any impact for the typical driver.

The numbers quoted for this particular vehicle are very optimistic I think. If you’re lucky, you might get 5 miles a day out of it. What happens if it’s cloudy or rainy for a week? Or you park in a garage? There are so many variables, and the return on investment will be highly variable.

Tesla decided it’s just not worth the extra cost and complexity, for such a small return. I agree the idea sounds nice, but I’m afraid these companies that are doing are this, are mostly just getting a nice PR boost.

There is just no way around the technical limitations of solar panels in the amount of energy they can convert, and the surface area of a car. Vans or RVs that could fold out a larger array when parked might be another story.

I will say, it looks like they have some real innovations in the design and engineering of integrating the panels in the body. Looks pretty cool, so that’s not nothing:)

topping up 5 miles a day means that a full battery will last me and the 1.8 million UK cars that do under 2000 miles a year, months between having to plug in and recharge.

- For me, 5 miles a day would keep the battery topped off and I wouldn't have to visit a charger except on longer trips.

- Would also be much more palatable to limit the full-charge voltage to something a little lower, prolonging the battery's useful life, knowing it'll passively recharge daily.

- Would also enable more connected vehicle features.

- Given a choice between a car that slowly loses a bit of charge daily, or one that gains charge, everyone would pick one that gains.

- Would also lessen the fear of running out of charge a mile away from a charger and needing a tow truck, just wait a few hours if it's sunny, or at least charge enough to park somewhere safe and phone a friend to pick you up and leave it for a day.

- Could go on camping trips a bit further away and let it charge for a week, or use the AC/heater occasionally.

- If the car is covered in snow it can warm up the panels and melt some snow. Teslas can already do this but it's even more practical with PV on the roof.

As long as people understand this doesn't mean they can drive nonstop in the sun or that they'll get any significant short-term range boost, it's still extremely sensible.

I suspect most people would choose the one which is $2000 less and looks nicer.

> Could go on camping trips a bit further away and let it charge for a week, or use the AC/heater occasionally.

Totally agree here, but I’m not buying a car based on what I do a half dozen weekends a year either. More important is to ensure you have bigger battery capacity. Buying the Model Y Long range, I paid $8k 80 miles more range. That’s going to be far more useful than the 5 miles per day you might get out of this.

This is all around something I might pay for as an upgrade, but certainly not an important part of the purchase decision.

Yes, those are all useful things but you have to (as a manufacturer, at least) weigh them against all the costs of building this feature, making production more complex, deal with the returns/breakages, etc. etc. So like the parent comment said, the consensus seems to be "just not worth it".

even a small ammount of self charging would go a very long way to make the car more pleasent to use.

Definitely.

> That's a 10 minute bike ride tops.

Perhaps, though it may not be possible cover that 2 mile commute by bike and survive.

At one point I was staying in a hotel along a small highway in Texas and saw a strip mall with restaurants on the other side. After about twenty minutes trying to find a way across I gave up and got in my car to cross the road.

Transit policy in many US cities and towns is somewhere between indifferent and actively hostile to anyone who is not driving a car.

In general, it’s a good idea to park your car under cover for a lot of reasons. Fabrics don’t do well when exposed to the high heat you get parking in the sun for prolonged periods. If you live or work in a city, chances are high that you are parking in a covered garage or basement.

Solar roofs on cars are a neat idea, but not likely near as useful for most people as spending the money on more batteries for longer range.

The best way to spend money improving an EV is almost always going to be on batteries or weight reduction. Self charging is neat, but unless you get much more efficient solar arrays, it’s always going to be limited to niche applications. Five miles more range is always going to be useful, solar arrays which add a mile or two of range under specific conditions are far less interesting.

But I did have one of those niche applications a while ago: I used to travel for work and often left my car parked random airport lots for months at a time which meant I occasionally came back to melted cassette tapes and a dead battery. In that case $100 of solar panels to run an exhaust fan and/or trickle charge the battery seems like it would have provided more utility to me than $100 of additional battery capacity.

I wouldn't be willing to add thousands of dollars worth of solar panels like the Sion and even if I did I wouldn't consider it a replacement for charging via the electric grid. But if my next car comes with an optional/after-market "solar package" that can integrate solar panels into the roof that seems like it would provide some value to me, at least more than the fancy wheel or audio packages they currently offer.

I probably come across as being more anti-solar roof than I am. Mostly just feel like this isn’t a feature I’d make a purchase decision on and wouldn’t likely pay too much for.

I was reading on the Tesla forums about just bringing a portable solar array for camping and it’s weirdly a lot more complicated than you’d think. Perhaps having it integrated would make it simpler, but it’s a lot trickier than just topping off a 12v battery with a solar array.

And if your only goal is to use it as an excuse to talk to your friends about having solar panels in your car then a small panel makes even more sense -- you can talk almost as much about a small panel as a large one for a fraction of the cost.

[1] e.g. https://www.coastaletech.com/power_outlet_mod.htm

My main point though, is that the amount of electricity you can collect from the surface area of a car is very negligible. It's a very ambitious goal indeed. It's not worthless, it's basically free energy so anything gained is good I guess. It just seems there are a lot of people here that seem to think this is going to be better than it actually is. It's easy to get hyped up by the marketing, but my suspicion is it is much worse that we would wish.

I'm very skeptical of the numbers they have posted. Especially in England where hours of sunlight per year is below average. A quick search suggests England on average get roughly 1500 hours of sunshine per year. Comparatively, my state of South Carolina get upwards of 2800 hours. You should be looking at the 'cloudy' bars on the chart (https://sonomotors.com/en/solar-integration/). Assuming the charts are right, that's 77 Km per week at peak summer, and as low as 21 KM per week in the winter, realistically. If the weather of favorable, and you don't park in shade, then sure you could get better results.

We have basically reached the limit of what we can extract from solar cells, and there is not enough surface area on a small car to make 'the dream' come true, of having the car charge itself without plugging in.

It looks great on the marketing campaigns though. And I'll give this company credit, their body panel system does look very innovative. It seems they have made some important enhancements in this type of solar tech. And all things considered, the more electric cars on the road the better, I hope they sell a ton of them!

And in fact, for my short commute and I'm sure at least a few others, it would mean never having to visit a charger except for long trips.

Still - I have an EV that's sitting idle most of the time because of the pandemic. I had to plug it in a handful of times this year, that would mean plugging it in zero times.

Also, if it is very sunny, it means the car is hot. One common thing to do is to start climate control before getting into the car so it will be at a comfortable temperature. We would get this heat rejection for free?

Is it worth it? Not sure. Maybe. Everything else being the same (including price) I would pick a car equipped like this versus another car without this feature.

By the way, some Nissan Leaf trims had a small solar panel to charge the 12v battery. That was useful. Mine has to periodically connect the traction battery to do the same.

"In England in 2018 – the last date for which figures are available – 9 per cent of household vehicles were parked in a garage overnight; 63 per cent were parked on private property (but not garaged); 25 per cent were parked on the street; and 2 per cent were parked in other places."

My main POV that I rambled around I guess, is I’m trying to temper expectations. Browsing through this thread, I’m just seeing too many folks who are expecting way too much out of this technology. I’m almost certain it will not deliver on the high hopes most people have for it. Even if that hope is you don’t have to charge on your very short commute.

It’s easy to get hyped up reading the marketing material on this company’s website. The idea seems great to the lay person. But the fact of the matter is when I hear Elon Musk say publicly that he and his team looked into it, & they determined it’s not an idea worth pursuing, I believe him.

Engineers & physicists way smarter than you and me have done the calculations. There is only so much energy you can get out tiny solar panels on a car body. Period. We’re talking about the laws of physics here. Conceptually it sounds amazing, in reality the result is lackluster.

Everyone wants to look at it with ‘best case scenario’ mentality, but day to day it’s just not going to be that effective. Again, not saying it’s nothing. There are some benefits.

But the added complexity of manufacturing? Could it be scaled larger than the 13K preorders they have? What happens when the panels start failing and need to be repaired? What happens when you get in a fender bender and half your ’solar grid’ goes offline, will you be willing or able to pay a specialist to repair the intricate solar grid in your car body?

It’s just a lot of effort and resources that could be focused elsewhere. Everyone is so excited because the concept sounds amazing, but the downsides & complexity are real. I seriously doubt this will power your car even for small commutes.

Cost is the reason. You have to consider cost.

You seem to be claiming it's better to travel 50 miles a day by car than 10 miles a day, which is clearly wrong.

I don’t understand at all how you interpret what I said to mean this.

Order these in desirability:

1) Not travelling 2) Travelling by car for 2 miles 3) Travelling by car for 20 miles 4) Travelling by car for 200 miles

I've already done it. In no world is it better to own a car and travel 200 miles than it is to own the same car and travel 20 miles. In all worlds it's better to not travel at all.

You are saying that "you shouldn't drive 3 miles". Unless you are also saying "you shouldn't drive 30 miles" and "you shouldn't drive 300 miles" you're being a hipocritte.

The reason I'm such a fan of taxes on externalities is to stop micromanagers saying "you shouldn't do that specific journey in that specific way", and instead give financial incentivies to do the right thing.

If the lifecycle of a car that lasts say 150,000 miles costs $5k in externalities up front and $15k in externalities, then charge those externalities -- $5k on the purchase price, then 10c per mile.

Even in a situation where the first 2 miles costs more per mile (because in an ICE the engine needs to warm up), then charge 20c for the first 2 miles and 10c after that. Someone doing 2 miles will pay 40c, someone doing 20 miles will pay $2.20.

The rest of this gibberish. I have no idea how you see this as a reasonable interpretation to either of my posts.

My point was that if it’s feasible to walk or ride a bike someone instead of drive, you should. I didn’t make it well, but I also didn’t suggest you are better driving 10 times further either.

You’ve gone from making a reasonable point to being damned near incoherent.

If you want more kilometers per day from the solar panel, it makes sense to optimize the car. More streamlining, lightweight composites, narrower tyres, wheel fairings, smaller battery etc. For example https://en.wikipedia.org/wiki/Lightyear_One

That might change in future and sooner than we realize, especially when current trend is about self-sustainability. Switching all cars to run on electricity does not mean, that in future there will suddenly be more electricity(that will mainly be green), than we have now, so owners of current Teslas in future might be slapped with extra tax, because they are not self-charging. Future Teslas might have solar panels installed, but hardly that will be concern of Elon Musk, as his main income is not related to Tesla Inc, where he now owns only 18% shares and he earns more from space by ripping off NASA.

Your understanding is incorrect.

Perhaps there should be legal escape hatches from HOA rules specifically for energy efficiency upgrades. I don't generally advocate for centralization of power (ie, a state imposing its will on a community), but in the case of climate change I'll happily make exceptions.

For example, the FCC has a carve-out that allows you to put up a satellite dish, in spite of any HOA regulation.

However, if a group of people want to make a legally enforceable agreement between themselves for their mutual benefit, then it shouldn't be possible for one of them to renege on that agreement later.

See also: easements (https://en.wikipedia.org/wiki/Easement). You can own property but if an easement exists then you can't do whatever you want with it. If easements were suddenly unenforceable, chaos would ensue. So the matter is certainly not as simple as "if you own something you should be able to do whatever you want with it".

Taking a wider view, HOAs are a form of free association and I can't condemn them entirely. If people want to subject themselves to complete hell, they should be able to. And frankly, the kind of neighborhood that has an HOA is not the place I'd want to live anyway, so it's not like I'm personally missing anything.

That said, the existence of HOAs should not be a driver for climate change, and aesthetics and property values are a really stupid thing to optimize for when we're facing catastrophic climate collapse.

I think an argument against this is that the HOA follows the property, not the consumer. If I could opt out of an HOA when purchasing a home, it wouldn't be so bad. (but then again, the HOA would likely be severely weakened.)

An HOA is effectively just a contractual micro-state, and conversely, some counties are a scaled HOA.

That said, I agree with you. I think HOAs are stupid, at least in the context of telling people what their shrubs should look like or what color to paint their house.

It's a fair argument that conversely many types of restrictions on what you can do are unjustified and overly broad, but arguing from the basis that you should be able to do as you please will fall flat on its face because it is so easy to find examples that would massively negatively affect neighbours.

Well yes, if you practice the tuba at 3am, raise alligators in your backyard, and beekeeping in your front yard, then yes.

But painting your house? Building a shed? Parking a car in the driveway? Building a fence? Adding architectural ornaments? Install solar panels? None of this stuff affects neighbours.

This would be too far. If the front yard and car are both my property it is not for anyone else to tell me what to do with them.

E.g. near me planning regulations generally prevent new construction from creating more than an average of 1.5 parking space per housing unit, to prevent further strain on the transport network. One might argue it's a poor proxy, as some people will have cars just sitting around, but it tends to work reasonably well.

There certainly is over-reach, and one of my pet peeve is that restrictions like this (and ideally all regulations and laws) ought to have stated justifications as part of the text, and "test conditions" to validate if they achieve the goal, as it's often hard to unpackage why the rules are the way they are, but a lot of these restrictions do have a reasoning behind them as well. Whether or not one agree about that reasoning is a separate issue, but I think a lot of conflict over these kinds of regulations boils down to not knowing the reasoning behind them.

I had a friend who lived in a dome house. It could not have been built in an incorporated area of his state.

If I own the land, I fucking own it, and I solely decide what is done with it. The HOAs do not own it, and they can fuck off. I live in the land of the free, and I'll build my dome. Mandatory HOAs should be outlawed.

Where you get into trouble is when they also try to enforce "property value" guidelines, which tend to become "against whatever the most power tripping person on the council thinks is 'ugly'". Solar panels are exactly the sort of thing that can be considered "ugly" and end up being banned. Beauty is in the eye of the beholder.

All of that stuff can exist without HOAs. If you want access to communal property and a communal parking sticker, you can require a membership fee. As long as it's reasonably priced I'd most likely gladly pay for access to parks and communal facilities and stuff like that. It should be optional, but for the above, I'd be likely to opt in and I'm sure most people would.

But no, I would not pay for them to come and yak at me for how I should decorate my front yard and house.

None of that stuff affects maintainence. Those farts shouldn't even be allowed to step on land they don't own.

The stuff that actually affects maintainence, I can understand, but participation should be optional by law. If you want discount maintainence, don't mess with your water pipes and electrical conduits. But hey if you're okay with finding your own maintainence, you should be entitled to do whatever you want as long as it's legal per fire/building code.

HOAs don't make a lick of sense for suburban blocks, but you can't do without them when you share a building.

[1] You could try the Soviet model, where people took care of their personal apartments, while the common areas and infrastructure of most buildings would go to shit. I've seen it, I'm not eager to re-live it.

I was referring more to HOAs for suburban blocks, which are extraordinarily common in the US. Many of them are obsessed about whether you can park your car in the driveway, what kind of car you're allowed to own, what kinds of plants you can plant in your front yard, the color of your house, modifications to the aesthetics of your house, and other stupid things. Welcome to the "land of the free".

It's maintained by an organization that is the exact same thing as an HOA, but is called a strata.

HOAs wouldn't be so bad if rules were grandfathered-in when you bought your house.

It's not your property. Stay out.

To be literal, the reason I think "I" (actually the HOA) have a say is because a bunch of legal paperwork says so. All the home owners signed it.

A year from now I won't have any say, because I won't be on the board.

Generally, I like the HOA since they mow my lawn. But if you are religiously opposed to being a member of an HOA, then you just wouldn't move into a house that's subject to one. All the people that live in this neighborhood were aware of it before they moved in.

Different people want different things.

They were forced to sign it if they wanted to purchase property. If it was optional I wouldn't be angry. To me the entire reason for owning instead of renting would be to be able to modify the hell out of it to my house of my dreams. Yes I could avoid moving into an HOA neighborhood, but HOAs are spreading like viruses and it's becoming increasingly difficult to find a place that doesn't have one.

I would just ask that the law make HOAs optional when purchasing property. If you want the benefits HOAs give you (if any), you're welcome to join, but you shouldn't be forced to join one just because you want to move into a certain district.

> A year from now I won't have any say, because I won't be on the board.

So now the house you supposedly "own" will be governed by some people that you don't even know. If they don't like your yellow car they could make a fit of it. I'm angry because if I owned property in a free country they shouldn't even be legally allowed to make a fit of something that isn't impinging on their freedom.

> Generally, I like the HOA since they mow my lawn.

I'd rather save the HOA fees and pay for a lawnmowing service.

> So now the house you supposedly "own" will be governed by some people that you don't even know.

"Governed?" I wouldn't really say that. I'm still allowed to take a shit whenever I want, and use as much toilet paper as I feel is right and proper.

If you want to argue about the existence of HOAs, I'm probably not the best counterparty. I don't feel too strongly one way or another. Just giving my perspective on whether HOAs would "lose their shit" over solar panels.

I don't deny you from your right to live in an HOA neighborhood, but I strongly oppose the HOA making it a requirement that you join them. It should be optional, and you can join if you want.

The existence of a (mandatory) HOA seems to increase property value. I have no economics training, but this seems to be a signal from the invisible hand that they are generally desirable in those cases.

The only ways they're likely to go away is if they're regulated out of existence, or they fall out of favor in a way that's reflected in property value.

To my neighbors who don't like solar panels because they "decrease property values" (the favorite bugaboo of HOAs), I reply that in 10 years any house that does not have solar panels will be perceived as deficient, especially in the southwestern US.

That is the time when a car parked in the hot sun causes the internal A/C to run to keep the car cooler.

Telsa cars will run the A/C when the internal temperatures reach 105°F (configurable)

This might be a good time to counterbalance the battery loss with the solar power peak.

I guess what I’m saying is, even if you had a solar trailer, you would lose a lot of the load flexibility of using a semi truck. And you wouldn’t want to plan a load where you needed the solar power. So either way, you’re planning for charging at fixed intervals. Solar might help a little here, but not very much.

You'd need some sort of standard for the trailer to provide electricity to a hybrid/electric truck but ignoring that (major) issue it seems like a pretty great idea.

Imagine what a similar investment in a stationary solar panel in that same yard would yield, a panel that will charge 100% of time.

That will have to be rolled out by the yards not the manufacturers of trailers. Trailers are leased as very few companies buy them.

It still doesn't work.

Delivery trucks make a little more sense, but they still have the problem of being in motion for a large chunk of the day. Basically you're just slightly increasing your watt mileage/range on sunny days.

Second, this idea of "charging" ignores a very real issue with cities - shading and latitude. Even if every single car on city streets had PV panels, it is always going to be less technically and financially efficient when compared to rooftop solar which has the benefit of being at a higher elevation and being able to produce more energy. Most cities with the combination of wealth and population required for something like this are not at the equator, they are not even close to the tropics. They are further north. Shading is a bigger problem there as houses of even 5 - 10 m in height cast long shadows.

Edit - sad to see that people here will take EV manufacturer's words as gospel and will downvote critical comments. Good luck to anyone purchasing vapourware such as this.

Cost, however, isn’t. The cells themselves are extremely cheap compared with the cost of putting them on a rooftop (in the case of homes), and in this case replaces the use of paint on the bodywork.

Specifically, the cost of cells is now down to ~$0.30/W, so 5 m^2 [0] of 200 W/m^2 would cost about $300. Similar arguments exist for PV roofing tiles being replacements for ceramic etc. tiles rather than the common sight of bulky window-size sheets attached after construction.

The claimed average range boost of 112 km/week (~3600 miles per year) in “average” conditions, and ~7900 miles per year in optimal conditions, definitely sounds about right to me based both on discussions last time a completely different PV consumer car was discussed here and on my BOTE calculations. Is that range worth $300 extra on the purchase price? Perhaps; it would pay for itself after ~1.88 years.

Doesn’t guarantee this isn’t vapourware (thinking of recent news about Nikola Corporation), but it is at least plausible.

[0] I am guesstimating the area

Also, what are "average" conditions? The website doesn't say. Stockholm or the Bay Area? This car will work much better in one of those places while in the other, PV panels on a car's roof are a gimmick. A relatively inexpensive and barely useful gimmick but still a gimmick.

Are you certain your panel costs are that low? Even NREL's estimates [1] put them much higher. Assuming that panel cost is roughly 30% of the US$ 2/W figure, that's still double what you're quoting and that's assuming cheap, mass-produced PV panels which the ones on this car most certainly are not.

[1]https://www.nrel.gov/docs/fy19osti/72399.pdf

Is it fair to claim that a speciality cell such as those on this car can be had for even cheaper? Unlikely.

$0.30/W global multicrystalline-silicon spot price.

I agree that buses and bus shelters are a good opportunity for solar, but this is a strange comparison.

First, if the panels really are as cheap as they claim (though I am skeptical) then wouldn't it make sense to do both? Why does it have to be either/or?

Second, I don't think anyone who is deciding whether to spring for the "solar" option on their electric car is weighing that against putting solar on their bus or bus shelter.

This problem of "energy" in particular electricity, can be solved, but requires buy in from millions of different parties (HOAs, building owners, real estate developers). Unless the law changes where you can compel / force these stake-holders to adopt solar panels, change will never come at scale in urban areas. It's possible, it just requires so much buy in from so many individual entities.

At 1pm my south facing rooftop solar array is at 97% of peak output, and by 2pm it's down to 82% and falls off pretty sharply after that. At some point in the afternoon the shadow cast from across the street would block that direct sunlight.

According to their specs, the car goes 255km on a 35kWh pack which is ~7.286km/Wh. It says it can produce up to 245km of range which is roughly 33.6kWh a week or 4.8kWh a day at best. In my case, it would be closer to half that value at best (2.4kWh), we've been having overcast days and my array has been outputting half it's normal capacity (1.2kWh). That's over 60km of range which would probably work for me but is 1 day's commute for a lot of people.

How many cars are custom painted today? Very few because of the high cost. Vinyl wrap has largely displaced custom painting, even in motorsports (which is not a particularly budget sensitive endeavor).

If the solar tech here costs consumers only what the Porsche PTS program costs, that would be the equivalent of around 35MWh of electricity generation to break-even (at a generous $0.20/kWh). That 35MWh is equivalent to around 140K miles of range that would need to be added to break-even. Sono Motors site suggests that 70 miles per week can be added. On a cash basis (without discounting), that's 2000 weeks or 38.5 years. If your local electricity is $0.10/kWh, the payback period is longer than your entire driving lifespan. If you discount the future at just 3%, it literally loses money every year.

This tech is cool, but fails to be practical IMO.

Of course, smaller cars will probably have a better surface-energy consumption ratio, I don't expect to make much of a range difference for larger and utility vehicles. It's something I'd add to offroad vehicles just for the cool factor (of independence), even if the range added per day isn't significant in that case.

It's hard to imagine a scenario where I accidentally run out of batteries and then can afford to wait for MULTIPLE DAYS before finishing my trip. Pretty sure I'd at least want to get a tow to the nearest gas station, where they would be able to plug me in if necessary. Even a plain old 120V 15A plug has much more power than solar, and works overnight...

In a lot of places, it's either keep moving or hope someone finds you fast enough. Not all roads are within throwing distance of a town or city.

In more common cases, it might be enough to cover limited driving (I think it might be able to cover my current car utilization in full), or at least offload the grid a bit. And in remote locations with limited or no power, it'll give occasional driving capabilities.

That's not a small amount. The US DoT puts average US driving at around 13,500 miles/year. In Germany (Sono Motor's home market) it's 8,000.

So we're talking meeting nearly 7.5% of US, and 12.5% of German, average driving needs. Just from sticking a solar panel on the roof of a vehicle.

If a car in a real scenario get more than 3% of it's miles from these panels I would be surprised.

Still, it does seem like a useful feature. It should be plausible to run out of juice relatively close to an outlet (gas station, hotel, good samaritan, etc.) since electricity is virtually everywhere. Waiting a few hours to get to the nearest facility should not be too bad.

It's more of the capability that attracts me (like having insurance without ever needing).

Given typical numbers of panel output I wouldn't be surprised if it (nearly) pays for itself anyway, so I don't see the need to be overly skeptical. (ben_w estimates ~1.8 year payback)

See other arguments cited elsewhere as well: avoiding deep discharge in case of battery depletion. If you leave your depleted car sitting for a while (days? weeks?), you will see degradation of the precious battery, which represents most (about 40%) of the cost of the car. A cheap insurance to preserve your most vital asset is also a great feature.

If Starlink does remove the location restriction, I'll spend more time in the wilderness than I do at home.

It might not be practical to plug in a place you’re staying at.

This argument gets thrown around sometimes, but if you really consider it:

Who has time to wait a day or two at a random place, with no infrastructure? People who have no valueable job (where time is very valueable), and at the same time are outdoors enthusiasts who can sleep in a random spot? But who at the same time are in the market for a futuristic EV? Even for those, how many times out of each trip would that be a viable solution? If you consider this in practices, it just makes much more sense to call the tow truck.

And if you know that you are going on a really long trip where there is really no possibility to even call a tow truck (but like, where is that? Where is the place where you have a close proximity to an EV charger, otherwise you wouldn't be going there, and no possibility for a tow truck to access?), even in that unlikely circumstance - you can just already buy a 1000$ 10kg diesel generator and bring with you for emergencies.

Some variation of this comes up every time: “but even a little bit helps” without knowing how little it is. I’ve got a Nissan Leaf. I’ve also got an RV with 400W of solar on top. That’s enough solar to keep things running all day on a reasonably sunny day. Unless you want to run the 1100W microwave, which you can run for fifteen or twenty minutes before you get to start over. Or you could drive an electric car for five minutes.

All this “doing the math” assumes perfect efficiency, blah, blah, to barely come out making it maybe kinda worth it. In the real world of cloudy days and off-angle sunlight, you’re better off having a sun roof put in and charging off your home’s solar panel. Or to put it more bluntly, until solar panel efficiency goes way up, panels on top of the vehicle is just dumb.

[1]https://electrek.co/2021/03/03/hyundai-ioniq-5-spotted-charg...

Only 244 kWh/year?!? You'd get the same amount of energy by plugging in to a basic 120V North American household plug every weeknight (you don't even need to charge on weekends!).

Or 30 minutes per weeknight by plugging in to a basic UK household plug.

Or you could just leave it plugged in to a household outlet overnight once per week.

For solar panels efficiency, two main things that matter are proper angle to the sun and amount of shade. Parking in the city, you cannot choose to align your panels with a sun. And you’ll be surrounded by tall structures (buildings, trees, etc) that will shade your car. You’ll get nowhere near close to an efficiency of a house rooftop solar.

You seem to be aware that this is not the case but also not so much... can’t tell what your comment is trying to support.

The 2018 MOV winner (https://www.americansolarchallenge.org/the-competition/ameri... ) logged 1762 miles over 58.4 hours, or about 30mph average pace (with a 16.8kWh battery, but no external charging, just the ability to time-shift some energy).

That's with a vehicle that looks like this: https://www.youtube.com/watch?v=aE9gkYsR4TU

myself and lot of ppl i know would be very interested in a car that basically charges itself when used only a couple times a week for short trips.

not for the electricy cost but mainly for the convenience.

... in June IF YOU ARE REALLY REALLY LUCKY AND PARK IN FULL SUN. Full sun in June, no thanks. How much of that will be eaten up by the extra cooling necessary?

You can work around by clicking the comments and then the link, but then you look at the top comment and are tempted to read and then respond.

A solar golf cart would be great for people in Arizona, but a car with a solar roof is meaningless almost anywhere and actually wasteful everywhere that doesn't have great sun.

Maybe the commenter you replied to is simply not gullible.

No, it must be fake, because it doesn’t fit my own agenda, and I don’t have the time to actually read any of the engineering info. I’ll just use my well-honed common sense to dismiss this totally impractical and stupid idea by physics and engineering grads. Do they think I’m dumb? I’ll show them by shouting even louder, and don’t you dare disagree or censor me!

(this is sadly the state of rational thinking today)

> I’ll just use my well-honed common sense to dismiss this totally impractical and stupid idea by physics and engineering grads.

Yeah, because nobody on here is a physics or engineering grad. Just us fucking uninformed hackers.

> Do they think I’m dumb? I’ll show them by shouting even louder, and don’t you dare disagree or censor me!

... Yes, I think they do. But yes, you're sure showing us.

> this is sadly the state of rational thinking today

Seemingly. You're mad when people point out scammy products being pitched at the scientifically illiterate. You aren't arguing about back about the numbers, but with an appeal to (some) authority.

Here is an article with more numbers on the solar charging: https://sonomotors.com/en/blog/park-the-sion-in-the-sun-and-...

Electric cars are great. If they can be solar powered, also great! Solar paint — sure, go for it!

Selling it as "the car charges itself" — really, no. That is dishonest and scammy.

The writeup just anchors this conclusion with excessive verbiage, itself a red flag, vague numbers about ideal conditions, and enticing but deceptive misdirection about oh-my-gosh we don't want to overcharge the battery now, do we? Snake oil.

There’s nothing else I can say at this point. Are you willing to dispute any of the figures or technical claims or just wishy-washy handwave the whole thing away?

But do let me know when it’s real (just to spell out what that means: physically available for normal consumers to buy, and delivered to them and driven by them in the real world, not as part of any restricted access rollout or prototype) and we’ll look at the empirical numbers then.

There are a lot of strong opinions out there based on ignorance.

It behooves one to take things, even so called engineering info you read on a marketing website, with a grain of salt.

BTW even universities do marketing, since you are apparently unaware.

I didn’t see anyone shouting. I hope you can see what is going on here.

Also you might get away with having less/smaller/lighter batteries if you're able to generate more power yourself.

If the car is decent as a plug-in electric car, then it still may be worth getting. If the solar panels are sufficiently non-intrusive they may even be close to neutral in terms of the utility of the car, but they do not improve it.

I think they improve the car not just from a convenience perspective (i rarely drive more than 100 miles a week in the city) but also it helps more of your energy usage come from the sun rather than non-renewable sources you might be indirectly pulling from the wall.

You make it sound like you're using a lot of power in that bus, but an induction cook top is at most 2-3 KW. That is 4 horse power. If you want to crawl at 5 mph that might be enough (but not for a skoolie anyway).

Cars have a huge power-plant under the hood. 100kW per car, at least. All the cars in a city have far more power than the power plant that supplies the city. Think 10k cars (town)= 1 GW. That is a nuclear reactor...

All the cars in the US, 275 million vehicles, at an average of 100KW, have a combined power of 27.5 TW. The total installed electrical power plants in the US are around 0.5 TW. The whole world has only 6 TW of installed power plants.

Cars need a lot of power...

The Ami can charge off 13A 240V in 3 hours (6kW motor and 5.5kWh battery pack), and is useful for a number of duties eg. school runs, shopping, mobility, bad weather.

Obviously the car featured here isn't designed around light weight<->practical charging but I reckon you could make an ultralight design for 4/5 people. The other problem is other larger cars on the road, that's a separate debate from the technical one.

The idea, and especially with the car in the article here, is that your car can charge over the course of a few days.

The power for electric cars is delivered from the battery. The Chevy Bolt for example has a 60kwh battery. If you have 1kw of solar, it will take you 60 hours of sunlight to charge that battery assuming the efficiency of those cells is close to what they're rated for.

The car from the article has a 35kwh battery so around 35 hours of sunlight to fully charge on 1kw of solar. If I drive ~100 miles in the city every week, and the car from the article gets the claimed 200-220w/m2 of solar - It's definitely feasible to recoup your entire driving usage by it just basking in the sun when you aren't using it.

Earth receives 1kW of power from the sun, per square meter. A solar panel has an efficiency of 20%. So under ideal conditions, sun directly at 90%, no shades, you get 200W per sqm. Now, you have shades, less than 90% angles, dirt, etc. On average in the US, the capacity factor of solar PV farms is 25% (includes day/night changes). You will get less on your car, but let's say you do get 25% capacity factor. That leaves you with 1000 * 0.2 * 0.25 = 50W per square meter, 24/7. In a week that is 8400 Wh per square meter. To charge the 35kWh battery once a week, you need 35/8.4 ~ 4 square meters. 4 square meters is plausible. You could say that the car has more space for PVs, but you kind of have to mount them such that they have a decent angle, otherwise their efficiency drops 10 fold.

In the case of Chevy Bolt, if you have a 1kW of PV panels, used in ideal conditions, you would need 1kW * 0.25 * 240h = 60kW. 10 days to fully charge the 60kWh battery. If you manage to install 1kW (4-5 square meters) of panels on a volt at ideal conditions (tilted 30-35%), then you could drive it 200 miles every 10 days.

On the other hand, if you only drive 20 miles a day, you could recharge at a power outlet and 60kWh would cost you 6 dollars. 6 dollars per 10 days, that means fuel cost would be $219 a year. That is $3200 for 15 years. Is it really worth installing a heavy and complex system on the car if you can achieve the same and better results by just laying the panels on the ground, next to the carport?

I am all for integrating solar PV in a lot more things, like house sidings and windows, but putting it on cars is just a PR move.

A typical electric car averages 4 miles per kWh. At a speed of 40 miles an hour that's an average power of 10kW - 10% of that 100kW peak power output.

As for the car, I imagine people will burn the energy and more by turning on the air conditioning when they get into their hot car that they intentionally parked in the sun.

Did you glue(/etc) the panels to the roof or did you have to mount them on standoffs?

I remember seeing my first solar panel leaning against an old blue and white school bus at a music festival somewhere on the west coast, decades ago. They had a bunch of old auto batteries for storage.

You could cool it a bit with a Stirling engine and get a little more power from the overheated interior. ;-)

However, they do degrade noticeably over the space of even a couple years.

I agree with this.

The net grid draw of EVs would decrease if every EV were equipped with solar panels. It's a way of turning the footprint of the car into a source of energy. Not sure how the manufacturing costs work out, but you don't have to replace 100% of the plug-in aspect to substantially reduce the energy costs.

They weigh no more than two kg per square meter including some environmental protection.

- don't drive very much

- but drive enough to spend tens of thousands on a new car

- but can't put a charger at their residence

- but can park somewhere that isn't shaded by trees or buildings or clouds or snow

Still, as the overall market for electric cars grows that can add up to millions of people. There's also another larger group:

- People who don't choose car options based on a fully considered rational utilitarian evaluation of cost/benefit

Which brings you up to >90% of car buyers ;). I'd probably pay for it if it's <$4000, it's much more utilitarian than 24" alloy wheels at least.

- Annual driving distance of petrol vehicles is 10000 km/year or less (250 km or ~155 miles per work week) [source: ACEA_Report_Vehicles_in_use-Europe_2017]. Extending this range by 112 km/week on average is not a bad proposition, if it's real.

- Average TCO in the first 5 years is over EUR 40_000 anyway [source: www.leaseplan.com/corporate/news-and-media/newsroom/2020/30-09-2020]. So most people who can afford a new car, can afford this one.

- The price tag EUR 25_500 is fair. VW Golf 8 is a vehicle of a similar size, and it starts at EUR 26_100, so it's basically the same.

- In the cities, street parking is often the only option, and most industrial areas use open parking; so getting some sunlight is not impossible.

So this tech is not more expensive than conventional vehicles (at least on paper). It can potentially reduce charging needs by 40% or more for a typical European user (who admittedly doesn't drive much). It's not very attractive without a network of easily accessible charging stations, but that applies to all EVs.

As you point out, by the standards of 'car accessories and upgrades', this one is probably reasonable and novel.

Looking at the chart they provide, that assumes perfect conditions in the month of June only. A sunny week in December will only provide 70km.

But going off the stated ‘average’ of 69.6 miles a week, roughly 10 miles for a whole day of collecting sun. You might get nice returns on a sunny day in the summer, but in general year round, your probably lucky to get 3-5 miles.

Elon Musk spoke about this on Joe Rogan recently, and said it’s just not worth it. The return on investment is just so small, and we’ve essentially reached the technical limits of what solar panels can provide. So we will likely never see this in a Tesla.

Tesla cars are heavier, twice as powerful and twice as expensive. Solar panels trade trade design freedom for utility. I'm not sure that big flat surfaces and an MPV silhouette would do well for a luxury vehicle.

Anyway, I think this product is fake and scam.

How much sunlight do they get in parking garages?

https://www.youtube.com/watch?v=wLZKdkgB85k

Obvious downsides include significant increases in repair costs in the event of an accident etc. But, panels have gotten cheap enough that this is at least worth considering.

PS: I agree it’s unlikely to turn into an actual product, but it’s at least theoretically possible.

Indeed.

I feel it is now like 1 in 3 EV projects as of late is a pure scam driven by stratospheric Tesla valuation.

Anything other than stratospheric sales from first year means they end up being dinner for existing manufacturers in low to mid-end.

And if they don't beat Tesla in the high-end, means they are dinner for Tesla.

Not to say a lion share of money still goes to people with zero automotive experience, or just above that of golf cart makers.

It's not a fake if its still in development, which it clearly is

About the fake, their car has suspiciously the same proportions than the BMW i3 and they have been accused of using many parts of an i3 in the past. But I want to believe they are trying for real. The i3 has a carbon fiber roof by the way.

This will only work in single-family homes. Where I live it's more common to have 4-floor buildings and street parking. In that case, the street gets enough sunlight for the car to charge enough for short-ish commutes (which are the norm for urbanites anyway).

> Anyway, I think this product is fake and scam.

I agree they are promising a lot, but they are not promising anything impossible. It's too soon to tell anyway and whoever invests in them must understand this is a high-risk/high-reward strategy.

A Tesla can charge more than this in an hour.

Solar charging ensures you only rarely have to plug it in to top it up, which is convenient. It also means that if you leave it sitting outside for long periods of time, it will be topped up rather than slightly drained when you get back to it. That convenience is not worth a lot of course but solar panels are cheap. And also, not having to pay for the electricity is nice.

E.g. my mother has a car that averages less than 3000 km/year (seriously). With this, she'd never have to plug it in (or rather visit a petrol station). My parents live in a small village and most of the trips are basically 15km round trips to a near by city. Something like this but a bit cheaper would be perfect for them and decimate their fuel expenses.

Will this cover all your needs? No of course not. But solar panels are cheap so the added cost of this convenience might be worth it.

No weight or vibration requirements, can use the electricity for your house too.

The only downside is you need to plug in.

Governments will likely be slow to implement on street charging. There is a market for something like this, if it works as well as they say - which I doubt.

[1] https://ec.europa.eu/eurostat/statistics-explained/index.php... [2] https://www.mortgagefinancegazette.com/market-news/housing/t...

[1] https://www.which.co.uk/news/2017/07/do-solar-panels-affect-...

Then you probably live in a city and would be better served by transport modes where you don't need a big upfront cost, and other expenses and hassle of owning your own vehicle. I mean bus, tram, metro rail, taxi, uber.

You can always qualify with further "what if you..." to find someone who matches this case. But by the time you're done it won't be a viable number of customers.

The cars are used to get away from crowds and from the city, to have some privacy and comfort and go out into nature.

There is black-and white reasoning about this because the maths around "what is the surface area of the car, how much charge can it generate and how far can it go on that charge" is also black-and white. And not favourable.

As the other reply says, this is not "the debate of electric cars"; this is the debate about this specific electric car design, with the solar panels on the car.

It's not talking about the current argument. It's saying the current argument shares the property of arguing against the use-cases of people outside the target demographic.

People who argue "electric cars will never be viable" (and not anyone in this thread) commonly complain about lack of supercharging speed, despite that being a feature that most people (and all initial adopters) will only use once or twice a year, if ever. This will not be a problem for a long time, as right now only ~1% of car users have an EV and that won't be a major problem until we start running out of ICE car-owning EV buyers who don't need that, which is at least at the 50% mark.

This particular car is priced quite nicely even if it came without this. So does not sound like there is a lot of extra cost.

I'm guessing manufacturers spend more on things like seat warmers or other stuff manufacturers put in cars these days. Also these things are probably more likely to break.

And if you consider the environment, imagine the energy savings over the life time of the vehicle not charging from (potentially) dirty sources. It would only be a waste if that energy wasn't used which would require you to religiously plug it in the second you stop driving.

Also, panels can be recycled (just like cars and batteries) and mostly don't contain that much nasty stuff to begin with. So, I don't see the problem here necessarily.

I can imagine this seems absurdly low for suburban America.

Otherwise, 15 min trips become 60+ ones which makes everything impossible.

People seem to think that just because things don't work where they live, that they must be impossible.

Even just getting around in inside the city, driving takes on average half the time of public transport. Shopping is much more convenient. It IS impossible to have public transport that delivers the same usefulness, speed and flexibility.

Owning a car still gives you a lot of freedom and flexibility to do what you want, when you want it. Which is not covered by car sharing at all.

I would gladly own a cheaper car only to do a weekly shopping trip and a weekly nature trip, something like 25km per week. Seems ridiculous to own a car for that short distances, but it gives a LOT of quality of life and I would gladly pay for it instead of using car sharing.

I live in a big city (London). Owning a car for me would be frankly insane. Where would I put it? If I was communing again, could not possibly take it in to work, there would be nowhere to put it at that end either, when I finally got through the traffic.

It is both much more practical and cheaper to use bicycle or bus and metro rail for commuting; taxi, minicab, or uber for other urban journeys; and car rental for weekends away.

I get that cases may vary. it's different further out from the city. But the idea that car = freedom, always, is very silly. I owned car here once, and it was liberating to get rid of it.

It seems that you have problems with your shared transport in your area, it sucks but maybe the better solution is better shared transport, not more private cars?

I live in a big city. Not owning a car for me would be frankly insane. How would I get to work? It'd take ~2 hours with public transport only.

It is both much more practical and safer to use a car rather than a bicylce (too dangerous) or bus (cannot reach where I go) and metro rail (Have to walk an hour for nearest station) for commuting; taxi, minicab, or uber for other urban journeys; and car rental for weekends away (all are too expensive in the long run).

I get that cases may vary. it's different in other cities. But the idea that car = burden, always, is very silly. I was unable to go where I want/need to go quickly until I got a car, and it was liberating.

There, fixed it for my case. :)

Of course, YMMV. :)

That's a nice full circle. :)

[0]: https://news.ycombinator.com/item?id=26474545