On a 24k car they've either gotten the price of the body panels pretty low or this is a loss leader. my hope is the former. If this car can live up to its promise this is exactly what I want as a city dweller that drives 200 miles a week.
The article said they reduced costs by not using glass for the solar panels, and by limiting the color options to a single color.
I don't know anything about car manufacturing, but that seems logical I guess. The car is ugly, but $25k for an EV with 190 mile range seems like a pretty sweet deal, even if the solar panels turn out to be a useless gimmick.
Your criticisms aren't the primary problem against solar.
Fender bender? I had a lady back into my challenger, plain unpainted black plastic was $3000. Sure I didn't pay... but in terms of solar panel. Cant be worse.
Dirty? An actual excuse to wash your car for legitimate benefit? In terms of power production if not, should be fairly minimal reduction with exception of bad conditions like winter.
Basically the power you can harvest isn't much. Even with the large flat roof of the samba. flipside, bad because the flat nose of the samba.
But lets say it works for you. you drive 2km to work and park in a sunny parking lot all day. It's not just expensive solar panels. It's the charge controller, it's the battery bms, its all these things you need to upgrade. These aren't trivial upgrades. The cost to integrate into a controller system like a tesla would double or triple the cost. solid state AC controllers are really expensive to beginwith. So in order to integrate solar into a tesla with their high power. It doesnt make sense. Take the money and put it in more battery or just charge off the cheap grid.
Flipside. Aptera did something slightly different. They are tremendously lightweight and aerodynamic. It lets them have low power to high performance. So in effect they have an equivalency to tesla in terms of power, but solar is handled.
What OP did was different since its not aerodynamic nor lightweight. They are VERY low powered. Their 0-60 times requires a calendar, not a stop watch.
Worse yet, there's not much you can really change here. There's no major breakthrough in technology which really changes this. There's really just not that much power even if you had 100% efficient solar panels. The solar state controllers are practically unimprovable, maybe room temp super conductors will help?
> It's not just expensive solar panels. It's the charge controller, it's the battery bms, its all these things you need to upgrade. These aren't trivial upgrades. The cost to integrate into a controller system like a tesla would double or triple the cost. solid state AC controllers are really expensive to beginwith. So in order to integrate solar into a tesla with their high power. It doesnt make sense.
Complete nonsense. If you're only getting 1-2kW peak then an MPPT and grid inverter is about $300. If you already had 95% of it, then integrating the MPPT with the rest would be $50 tops. You could make a ghetto version of this at early-adopter retail prices with 800W of Sunpower 2mm thick flexible panels, some silicone adhesive, a 500Wh battery as a buffer, a full sine wave inverter with a timer/voltage control plugged into your normal 240V charger and a standard low power MPPT. It would cost about $3-4k and half of the added cost would be from the redundant step-up step-down of voltage and needing a buffer to satisfy the charger. You'd have to run your charger cable from the inside and you'd lose more power from reduced aero from the junction boxes than you gained if you went on the highway (unless you were willing to cut into the roof to put them under), but it's enough to prove your cost argument is wrong.
The cells would be $500 max at volume. Integrating them to the body would be the only expensive part.
It's not really viable for something as wastefully big and powerful as a tesla, but for an econobox you could add 10-20km/day fairly easily. Once perovskites are a thing the cell integration costs go down too.
The argument was true when monocrystalline panels were expensive, fragile and exotic. Now they're not. The main reason not to do it is people would bitch about appearance, then get weird expectations and it would be bad PR. This isn't worth charging a big luxury car ~one fewer times a month.
But mostly-not having to charge a city runabout that does <20km/day is a pretty compelling argument. People that buy econoboxes have much less fragile egos so won't clutch pearls about being able to see a functional element as much, and are more likely to lack the ability to plug their car in at home so not having to go find a charger every week is a more compelling feature. I'm not sure if the Sion hits this demographic as it's quite big and heavy and may be trying to do too many things. I expect the aptera to fill this niche quite well if it doesn't get legislated out of existence.
This has always seemed like the most stupid-obvious idea to me. It's amazing to see some recent examples getting closer to production! There are also mod kits available for some EVs which allow you to attach solar body panels that charge the propulsion batteries. And we have some examples of fully solar-powered EVs that have empowered nomads to travel the world without refueling or charging from electric grids. The fact that this is not already normal is insane.
The car this article is about gets 10-20 miles a day.
Also "optimal sun conditions" obviously means keeping your car in direct sunlight the entire day. That rules out putting your car in a garage, which consequently rules out most urban use where short distances would be sufficient for most use.
depends on your neighborhood/city. a lot of places in the US make heavy use of street-side parking. at the least, it does position itself counter to any push at more efficient land use in cities.
Maybe it's useful in small towns with low buildings and low street crime. In my neighborhood, tall buildings shade the streets for much of the day, and I wouldn't like to store my car outside anyway due to the property crime. There are also a lot of trees, which are quite nice but would frustrate anybody with a solar car.
So mass adoption of solar cars would discourage tall buildings and tree-lined streets.
Street-side parking in urban areas still doesn't get direct sunlight more than a few hours a day, since tall buildings block the sun. Perhaps useful in a few west coast cities, but usually it's either "short buildings + garage" or "tall buildings + outdoor parking".
As someone who worked at America's only electric vehicle charging manufacturer, the average commute is about 30 miles. With EVs like the Bolt getting 3.9mi/kwh, that comes to 7.6kwh/day. At an average daily solar production of 5 hours at rated capacity, that's 1520wh of production capacity or about a hundred square feet; less than a third the surface area of a normal parking space.
Simple, just recharge it like any other electric car. The main point of solar on cars is so you don't have to bother recharging just for your daily driving around town.
Lots of extra cost + weight + complexity for marginal benefit. In very specific scenarios it makes sense, but it's usually better to just put the panels on your roof. Most people when shopping for EVs are concerned primarily about single charge range, which solar panels don't really help with. I'm interested to see what these companies come up with, but the proof will come if these companies are still around in 5-10 years.
$100 + labour for assembly + testing to make sure the panel works + the cost of an extra DCDC converter + wiring to the roof + supply chain risk with all the above parts. Toyota tried it for a while, but I don't think any new Prius models have a solar roof.
Which are all quite minimal costs compared to many other features with very little or negative utility.
Like anything with cars it's purely a matter of fashion, ego, and perception. Noone who isn't making a purely emotional decision buys a new car. Adding a thousand or two and 5kg is completely irrelevant. If people don't percieve an extra 10-20 miles a day as worth the ugly blue rectangles, then the one with them could be 200kg lighter and $5000 cheaper and it still wouldn't sell.
My car spends the majority of its life in a covered parking structure. Solar on roofs (as sibling comment also suggested) probably makes more sense in the vast majority of cases.
It only seems obvious until you try to build one. The people in the "Sunrayce" have been doing this for 30+ years. What you get is a hugely inconvenient fared e-bike with no night capabilities. The amount of sunlight that hits a car-sized object just isn't that high. Everyone is the real world is better-served by a regular old bicycle, or an electric car.
There's no innovation here. The economics of solar panels are not making them any more efficient, just cheaper. The ideal aerodynamics were solved long ago. This car that Cal entered in the Solar Challenge 2022 is substantially the same vehicle they entered in 1997. https://calsol.berkeley.edu/
It isn't that stupid-obvious for engineers [0]. It is just too little solar panel on a roof that you'd rather not leave out in the sun. Also, expensive.
> The fact that this is not already normal is insane.
I don't know anyone who would want to buy the car in that article. I know plenty of people who have EVs, and I have one too, and still I don't think a single one of my EV-owning friends would buy that car. It's too compromised.
What makes a lot more sense is to put the solar panels on your roof and use them to charge a normal EV, all of which are better at being cars than this thing is. Doing so can also reduce your power bills, heat a swimming pool, and even charge a battery that can power your house during grid outages.
Solar power is great! But the panels don't need to be attached to the car to be useful.
You don't seem to understand the argument. Your car is covered in body panels; those panels could be producing the power to recharge the car. It doesn't matter what the car looks like; any car could work this way.
Solar cars are scam. They are designed to get funding out of investors with poor understanding of technology.
Do some basic math. The electric energy harvested with the solar panels is negligible for transportation.
And why should we want to move around solar power plants? It makes much more sense to have them stationary. And to connect them to the power grid to sell the energy to others when the sun shines but the batteries are full.
>Solar cars are scam. They are designed to get funding out of investors with poor understanding of technology.
They certainly exist, it's just not the performance numbers people want from their vehicle.
>Do some basic math. The electric energy harvested with the solar panels is negligible for transportation.
Thats not true; and also depends on your usecase. Aptera is certainly going to come to market with a product for example, but does your usecase allow a 2 seat death trap? What if you have to have a baby seat? Surely nobody is putting children in it.
But if you're a bachelor looking to reduce your cost of transportation to 0. Damn what a good option.
>And why should we want to move around solar power plants? It makes much more sense to have them stationary. And to connect them to the power grid to sell the energy to others when the sun shines but the batteries are full.
1kw on your car is hardly comparable to a major solar array. By the same argument you can deny any solar purpose. Which isn't reasonable to many use cases.
Give me a cheap EV glued together in India out of plastic parts rather. Or a nice e-bike. The solar on the car is just a gimmick. Put the solar on my roof rather.
> > And why should we want to move around solar power plants? It makes much more sense to have them stationary. And to connect them to the power grid to sell the energy to others when the sun shines but the batteries are full.
> "[...] By the same argument you can deny any solar purpose."
I don't follow. Can you expand on this line of reasoning?
Its a $30K car with a range of 190 miles and can charge itself 40 miles a day in optimal conditions.
I live in southern california and I drive about 20 miles a day under normal conditions.
Today I have solar panels on my house and a plug-in electric car, but I think the value proposition of a $30K car that I never need to plug in or refuel (during normal conditions) is pretty compelling. The solar panels on my home can spend time offsetting the rest of my lifestyle
Outside of the geeky cool factor, what precisely is the value proposition? You say you have solar on your house. So is it that you don't have to remember to plug in? Is that a big deal for most people? What if there was some kind of auto-connect when you pulled into your parking spot? Would that be better than carrying around solar panels that don't point at the sun?
I read through the absolute technical limits of solar cars once and promptly crossed the idea off in my head. Might as well just have 1000w of folding panels in your trunk that you can set out if you really need off grid charging.
I suppose I could imagine a scenario where maybe a city dweller who doesn't drive much could street park and they could do their grocery runs and occasional running around from the solar self-charge. Then you would be looking at less trips to the public charger. It's probably pretty common in Manhattan to do less than 10 miles a day so you'd only end up at the public charger when the weather was bad.
I think it could make even more sense in places like Arizona: fewer clouds, trees, and tall buildings.
Kind of interesting to ponder that we might soon have car SKUs that are much more regionally localized: a car that works great in CA or AZ, but is entirely impractical for the midwest. (However, I suppose that describes 'convertibles' pretty well)
Well electricity in the Bay Area costs about $0.50 per kWh (or $0.25 per kWh at night using the ev2-a plan, though it makes everything else more expensive).
Having a car that can gradually recharge itself over the day can actually save hundreds of dollars per month (my last bill was like $600), without having to deal with the hassle of installing rooftop solar and having to pay extra money just for having solar installed [1].
Technical limits change. The marketing is kinda dishonest (picking perfect conditions during high latitude mid summer), but 10-20mi/day is achievable in many areas/times.
The main value proposition I see is an urban renter or someone with only outdoor parking (who also drives less than a suburbanite) only needing to seek out a charger once a month (or maybe not at all during summer). It also lowers grid load from this demographic that would otherwise charge over short durations by 30-80%.
EEVblog has an informative video on this topic [1] looking at the 'Lightyear Zero' solar car (not the Sion Sono Motors this article is about)
The presenter is in Sydney, he's got a large roof-mounted solar array - 8kw peak output, and about 8x the area of the cells on the car. And he still struggles to cover a 25-30km daily commute with solar, achieving it only 80-90% of the time.
And good luck parking your car somewhere that gets more sun than a rooftop installation in Sydney :)
However, the Sion's $25,000 price tag is a lot better than the Lightyear Zero's $250,000 price, so they've got that going for them.
"can charge itself 40 miles a day in optimal conditions." <- I believe this is the "basic math" that you were asked to run.
Using random numbers from Google for a Tesla 3 for an example, it has a 50kWh battery and 305 miles of range. That's 164Wh per mile. 40 miles would require 6,560Wh.
Assuming you leave the car in perfect sunlight for a full 8 hours every day, and there's no cloud, and you get 100% sunlight for the entire 8 hours, then you'd need enough panels to produce 6560Wh / 8hr or 820W.
I could probably barely fit 300W-400W worth of panels on top of my vehicle, and that's with covering the hood, trunk, roof, everything.
So even in the MOST IDEAL possible scenario, where you have your car in perfect sunlight for 8 hours a day, you're not even half way to producing 40 miles per day.
Your error was in presuming the same weight and drag coefficient as the Tesla. The Aptera is both much lighter and has a far lower drag coefficient. That's where the extra range comes from despite the relative lack of surface area.
The apteta isn’t the subject of this article though. The aptera is legally not even a car, as it’s a 3 wheeler. It’s a pretty extreme vehicle. Very cool, but quite extreme. The subject of the article, is trying to be a normal 5 door car. So comparing it to the state of the art in normal cars makes sense. The claims with this car are aptera performance (40 miles a day) but with normal car form. How is that possible? That’s why people are suspicious.
The aptera has 750W of solar panels, so you're pretty close.
It also has about 40% less Cd, half the frontal area, much less powerful motors nd a fraction of the weight. Which is how you get from 8 hours of sunlight to 5.
Real world it's probbably more like 20-30mi
The most likely reason it won't become common is it's legally a motorcycle to get the weight down to something sensible (or has no legal category in some areas) because cars are a regulatory captured nightmare and we're literally not even allowed to have a sane sized vehicle.
The lightyear and sion are much closer to vaporware and their marketing departments are doing the concept a great disservice, but they have over a kW of panels and you could reasonably expect them to be mostly self charging if your commute is short or it's just for errands.
Over the last 14 years I have driven less than 22 miles per day on average. Considerably less if you cut out long road trips and the six months i commuted 80 miles per day. A solar car with these specs would easily have handled my driving needs without charging on 90% of my days in the last decade, likely considerably more.
The advantage of a solar car has little to do with saving trivial amounts of electricity. IMO, the best use case is for a hybrid which isn’t generally plugged in as now you’re saving gasoline which could quickly pay for the panels.
More widely for EV, there is no need to worry how much charge you lose when parked for long periods. Not needing to worry about running the heater or AC during a traffic jam. Being less dependent on the electric grid during a natural disaster is an edge case, but still very real. Less real but still marketable is the prepper end of civilization argument.
And of course long term things start looking even more interesting as panels improve.
Why would the panels improve? Monocrystalline silicon cell efficiency has been about the same since the 90s: 15-20% for commercial cells, up to 26% in the lab.
The article mentions the Sion is using lower efficiency polymer-based cells integrated into its body panels. But also the curved panels ideal for aerodynamics means a real tradeoff, as current curved panels have poor efficiency.
Right now nobody is going to heavily invest in solar car R&D, but if this becomes a common feature the simple desire for longer solar ranges is going to push efficiency.
In their own marketing materials they say that they are using monocrystalline cells. However, there is no reason to take any of these statements seriously as the whole operation is transparently a scam.
Mono cells haven't been affordable for more than about 8 years. In the 90s it was 8% poly cells in anything affordable. Now you can get 22-24% glassless cells for a dollar or two per watt retail (or much less in bulk).
Much work is being done to commercialise hybrid tandem cells with growing confidence they'll be here this decade. You could similarly say "polyjunction cells have been about 32% in the lab since the 90s" once they are dominant.
Similarly boosting coverage ratios from the 70% of painted area or so of the current three concepts to 95% is possible now but not economic. As are thin film 10% efficient transparent cells in lieu of tinting over the side and rear windows.
A 40% improvement in car efficiency (the sion is heavy and boxy so there's room), with a 40% improvement in coverage and a 30% improvement in panel efficiency (or 50% in poor weather where it matters) would take it from 'okay, I guess that kinda maybe works sometimes' to 'when was the last time I plugged it in outside of a road trip?'
How many of those people leave their car parked in direct sunlight the entire day? I use my car for city errands but it spends 99% of the time in a parking garage. The few minutes a day my car is outside in use could provide what, a hundred meters worth of juice? Useless.
Even if I wanted to store my car parked on the street, I don't even know where in my neighborhood I could do that. There are trees and tall buildings that shade nearly every street for at least a substantial part of the day.
I live in a suburb. Despite nearly every house having a garage, almost everyone parks in the driveway or on the street and uses the garage for storage or other purposes. And the way the trees (minimal, and mostly in backyards) and houses are laid out (primarily single story ranch houses) I would estimate that most vehicles spend at least 60-70% of the day in sunlight (particularly so during the mid-day period where the highest irradiance is available) if not more. And conveniently this suburb is about 10 miles away from a handful of different office hubs. A car like this would be a massive hit here. EVs are already taking off (I am seeing a ton of Bolts). Not having to plug in every night would certainly be a popular selling point.
Just because it doesn't work for you personally doesn't mean it is a bad idea.
My car has spent basically 100% of the last 5 years exposed to open sky, ever since moving away from a place with trees. Both my home and workplace parking situations have good sun exposure. Most of the spaces at my apartment complex have good sun exposure as a lot of the spots are set back from buildings.
there’s a market for this, even if it’s not you. the bulk of my daily travel happens by bike. i keep a car around for visiting friends/family in the nearby suburbs on the weekends. a typical week would have me driving it between 20-40mi. at that point, i can have an EV without having to upgrade any wiring in my home, or having to fight the roommates over our one off-street parking space where i could even plug an EV in.
the reason i wouldn’t buy this (yet)? i’m too cheap. since i spend so little time in a car already i can’t imagine ever paying more than $10k for one. by the time this model hits the used market i assume the solar efficiency and battery capacity will be about half what it is new, which might be too limiting for me. maybe future revisions will improve enough to counter that... or maybe the initial market is too small that they won’t be able to overcome that initial hurdle and build out.
but the product idea has some merit: i still wouldn’t write it off entirely the way a lot of people here are.
As someone that had to charge their EV by running an extension lead out of their first floor flat window, this is a compelling offer.
In the UK there's a large number of people that do not have dedicated parking (24.6%, or 6,642,000, of UK households [1]) making it more difficult to charge at home and benefit from reduced electricity prices through smart charging. If the cost of an EV with solar panels is comparable to other EVs this would help alleviate some of the issues faced by this set of drivers.
This is a mostly dumb and gimmicky idea. It will fail. If we want serious climate solutions we need either a massive build-out of nuclear power or wind plus utility-scale battery (or potentially ammonia) storage. Solar energy has a ridiculously low EROI. Solar energy on a car? Probably an even lower EROI.
You're fifteen years out of date. A 2022 PERC cell has an EBPT of about 3-6 months and can be recycled after 30 years into a slightly worse cell which will last another 30 years. Only wind comes close.
> A 2022 PERC cell has an EBPT of about 3-6 months
Okay, so there's a new solar cell that is slightly better and perhaps can be manufactured a little cheaper. Great! So what? You have failed to take into account the burden of energy storage. The capacity factor for solar is an abysmal ~20% if not ~10% in some localities. Wind can have a superior capacity factor of up to ~50%. Energy storage is the constraint.
Renewables can provide about 30% of world electricity with no storage. Cheap storage like thermal (so the cheapest sand) and concentrating solar (even better EROI, comes with 12hr storage and is getting close to the price of gas) can make it provide another 20% of electricity and the 20-30% of primary energy that is low grade heat.
PWRs can provide about 30% of world electricity and that same low grade heat and then you run out of Uranium. It also requires overprovision or storage for fluctuating demand and planned downtime and has correlated failures on the order of weeks or months. A capacity factor of <50% of the french fleet this yeae with unplanned correlated outages of 3 months during winter is far worse than new offshore wind with 65% forecastable output that fluctuates daily.
Even with current storage technologies the nuclear option costs more than adding enough storage to cover the next 30% with renewables.
Also your initial conceit was putting a solar panel on a 1 week battery to suppliment its input by a few miles a day. The constraint here is efficiency, daily mileage, travel velocity and area. You're welcome to keep bringing up boring predictable reactionary lies (I'm guessing something about density while ignoring the difference between fertile and fissile is next, then MOX, then breeders, then sea mining, then lies about mining), but this point has been fully addressed.
Won't happen anytime soon. There's a lot. We have a century's worth, and the uranium price could easily be three times higher, without hardly an impact to utilities, and unlock more reserves and exploration.
> capacity factor of <50% of the french fleet
This not an indictment of nuclear power as a whole.
American nuclear reactors have a ~90% capacity factor.
> Cheap storage like thermal (so the cheapest sand)
Won't be effective for producing electricity. Might only be ~30% efficient.
> far worse than new offshore wind
Wind is reasonable but don't forget that reactors can last a ridiculously long time ~75 years. Wind turbines might only last ~20 years in a corrosive environment.
Oh we're doing the thing where you lie about things that have already been addressed
> Won't happen anytime soon. There's a lot. We have a century's worth, and the uranium price could easily be three times higher, without hardly an impact to utilities, and unlock more reserves and exploration.
A century at 300GW. Quadruple that and it's 25 years. Replace 2/3rds of electricity and it's under 20. And those are reserves at a price 3 times higher. New lower level reserves will be even more expensive to the point where the LCOE of solar is around the raw uranium price.
> Won't be effective for producing electricity. Might only be ~30% efficient.
...Which is why I suggested it for the 20-30% of primary energy that is low grade heat where it is 100% efficient.
> This not an indictment of nuclear power as a whole. American nuclear reactors have a ~90% capacity factor.
If you want the anomalous US reliability, then you can't pretend you're going to pay historic french or japanese prices. Also what's the capacity factor of US nuclear reactors where construction started this century?
> Wind is reasonable but don't forget that reactors can last a ridiculously long time ~75 years. Wind turbines might only last ~20 years in a corrosive environment.
When individual unplanned repairs, or regular planned maintenance for a decade, or mid life refurbs cost more than an entire new wind turbine, this is a massive downside, not an upside. Pre-paying for 75 years worth of electricity rather than 25 means you can only build out a third of the capacity (or a twelfth given the much higher user facing cost per kWh even if you can find the cash to keep hiding the larger hidden costs)
But before you can start gaslighting about the economics you have to demonstrate that it's physically possible. Which you have not done.
Nuclear can make a small contribution, but it cannot meet the scale of renewables.
> New lower level reserves will be even more expensive to the point where the LCOE of solar is around the raw uranium price.
No. From the World Nuclear Association, "doubling the uranium price (say from $25 to $50 per lb U3O8) takes the fuel cost up from 0.50 to 0.62 ¢/kWh, an increase of one-quarter, and the expected cost of generation of the best US plants from 1.3 ¢/kWh to 1.42 ¢/kWh (an increase of almost 10%)."
Uranium could easily be $300/lb and nuclear will still be competitive.
> Pre-paying for 75 years worth of electricity rather than 25
Yeah, "electricity" which is intermittent and currently requires Russian and Qatari natgas to load balance... or perhaps you can re-open some coal mines. Pick your poison.
Uranium is already over $50/lb. Doubling (which isn't even historic highs which were >$120/lb) would add 0.2c/kWh in the best reactors or 0.3-0.4c in the current fleet which is around 15-25% of a solar or good wind project's LCOE. The historic high happened when there was a small shortfall in production in two mines, and you're talking about quadrupling production overnight (because you need around 6 years of fuel to switch it on) just to meet the current pace of renewables.
> Uranium could easily be $300/lb and nuclear will still be
competitive.
$300/lb is $14/MWh which would put it precisely a dollar above the PPA price of recent indian and mexican solar projects in the current fleet, or $10/MWh which is projected 2025 prices in a high burnup reactor. Ie. Raw Uranium alone would cost more than renewables total cost whilst still only making up a quarter of the marginal costs and a tenth of the total cost.
> Yeah, "electricity" which is intermittent and currently requires Russian and Qatari natgas to load balance... or perhaps you can re-open some coal mines. Pick your poison.
Replacing 50% of electricity and 30% of primary energy without any electrical storage at all is still double what is possible with nuclear which will require that gas and coal to be running 24/7. 4 hour storage and more variable loads (like replacing fossil ammonia) can push this up to quadruple the maximum physically possible contribution from PWRs.
Also before you start gaslighting about storage you need to demonstrate that PWRs can do better than renewables with no storage if the PWR has 0 capex or build time, or that nuclear doesn't need 4 hour storage for meeting variable loads. Which you haven't.
You're about an order of magnitude off. 2.4 kWh/mi is a total range of 40 mi for a 100kWh battery.
Very good panels are 24%. A reasonable capacity factor for something car shaped is 10%
So about 20 miles/day in an open parking spot.
More realistically there's probably a lot of spaces you couldn't fit a panel on, so maybe 10-15mi/day reliably in most places. Enough to significantly reduce charging for a moderate commute and errand runner or eliminate it during summer.
I'd be a bit sceptical of their claims of reaching similar with polymer cells with such a boxy car though.
It's a nice idea, but the black color is going to be a serious problem for car that you park in the sun. I suppose they could have cooling fans running in it while it's sitting, otherwise the interior and battery are going to bake. Any plastic parts that aren't high-temp will go brittle.
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[ 2.0 ms ] story [ 139 ms ] threadAnd if you're in an area prone to drought (like places that get plenty of sun), washing your car may not even be feasible.
I don't know anything about car manufacturing, but that seems logical I guess. The car is ugly, but $25k for an EV with 190 mile range seems like a pretty sweet deal, even if the solar panels turn out to be a useless gimmick.
Fender bender? I had a lady back into my challenger, plain unpainted black plastic was $3000. Sure I didn't pay... but in terms of solar panel. Cant be worse.
Dirty? An actual excuse to wash your car for legitimate benefit? In terms of power production if not, should be fairly minimal reduction with exception of bad conditions like winter.
The actual reason why its bad and elon musk talked about it. Jehu garcia has a good video. omg 8 year old video: https://www.youtube.com/watch?v=Kg_7rJs8hLs
Basically the power you can harvest isn't much. Even with the large flat roof of the samba. flipside, bad because the flat nose of the samba.
But lets say it works for you. you drive 2km to work and park in a sunny parking lot all day. It's not just expensive solar panels. It's the charge controller, it's the battery bms, its all these things you need to upgrade. These aren't trivial upgrades. The cost to integrate into a controller system like a tesla would double or triple the cost. solid state AC controllers are really expensive to beginwith. So in order to integrate solar into a tesla with their high power. It doesnt make sense. Take the money and put it in more battery or just charge off the cheap grid.
Flipside. Aptera did something slightly different. They are tremendously lightweight and aerodynamic. It lets them have low power to high performance. So in effect they have an equivalency to tesla in terms of power, but solar is handled.
What OP did was different since its not aerodynamic nor lightweight. They are VERY low powered. Their 0-60 times requires a calendar, not a stop watch.
Worse yet, there's not much you can really change here. There's no major breakthrough in technology which really changes this. There's really just not that much power even if you had 100% efficient solar panels. The solar state controllers are practically unimprovable, maybe room temp super conductors will help?
Complete nonsense. If you're only getting 1-2kW peak then an MPPT and grid inverter is about $300. If you already had 95% of it, then integrating the MPPT with the rest would be $50 tops. You could make a ghetto version of this at early-adopter retail prices with 800W of Sunpower 2mm thick flexible panels, some silicone adhesive, a 500Wh battery as a buffer, a full sine wave inverter with a timer/voltage control plugged into your normal 240V charger and a standard low power MPPT. It would cost about $3-4k and half of the added cost would be from the redundant step-up step-down of voltage and needing a buffer to satisfy the charger. You'd have to run your charger cable from the inside and you'd lose more power from reduced aero from the junction boxes than you gained if you went on the highway (unless you were willing to cut into the roof to put them under), but it's enough to prove your cost argument is wrong.
The cells would be $500 max at volume. Integrating them to the body would be the only expensive part.
It's not really viable for something as wastefully big and powerful as a tesla, but for an econobox you could add 10-20km/day fairly easily. Once perovskites are a thing the cell integration costs go down too.
The argument was true when monocrystalline panels were expensive, fragile and exotic. Now they're not. The main reason not to do it is people would bitch about appearance, then get weird expectations and it would be bad PR. This isn't worth charging a big luxury car ~one fewer times a month.
But mostly-not having to charge a city runabout that does <20km/day is a pretty compelling argument. People that buy econoboxes have much less fragile egos so won't clutch pearls about being able to see a functional element as much, and are more likely to lack the ability to plug their car in at home so not having to go find a charger every week is a more compelling feature. I'm not sure if the Sion hits this demographic as it's quite big and heavy and may be trying to do too many things. I expect the aptera to fill this niche quite well if it doesn't get legislated out of existence.
Also "optimal sun conditions" obviously means keeping your car in direct sunlight the entire day. That rules out putting your car in a garage, which consequently rules out most urban use where short distances would be sufficient for most use.
So mass adoption of solar cars would discourage tall buildings and tree-lined streets.
Like anything with cars it's purely a matter of fashion, ego, and perception. Noone who isn't making a purely emotional decision buys a new car. Adding a thousand or two and 5kg is completely irrelevant. If people don't percieve an extra 10-20 miles a day as worth the ugly blue rectangles, then the one with them could be 200kg lighter and $5000 cheaper and it still wouldn't sell.
There's no innovation here. The economics of solar panels are not making them any more efficient, just cheaper. The ideal aerodynamics were solved long ago. This car that Cal entered in the Solar Challenge 2022 is substantially the same vehicle they entered in 1997. https://calsol.berkeley.edu/
[0]: https://youtu.be/xIokNnjuam8
I don't know anyone who would want to buy the car in that article. I know plenty of people who have EVs, and I have one too, and still I don't think a single one of my EV-owning friends would buy that car. It's too compromised.
What makes a lot more sense is to put the solar panels on your roof and use them to charge a normal EV, all of which are better at being cars than this thing is. Doing so can also reduce your power bills, heat a swimming pool, and even charge a battery that can power your house during grid outages.
Solar power is great! But the panels don't need to be attached to the car to be useful.
That's why this is not already normal.
Do some basic math. The electric energy harvested with the solar panels is negligible for transportation.
And why should we want to move around solar power plants? It makes much more sense to have them stationary. And to connect them to the power grid to sell the energy to others when the sun shines but the batteries are full.
They certainly exist, it's just not the performance numbers people want from their vehicle.
>Do some basic math. The electric energy harvested with the solar panels is negligible for transportation.
Thats not true; and also depends on your usecase. Aptera is certainly going to come to market with a product for example, but does your usecase allow a 2 seat death trap? What if you have to have a baby seat? Surely nobody is putting children in it.
But if you're a bachelor looking to reduce your cost of transportation to 0. Damn what a good option.
>And why should we want to move around solar power plants? It makes much more sense to have them stationary. And to connect them to the power grid to sell the energy to others when the sun shines but the batteries are full.
1kw on your car is hardly comparable to a major solar array. By the same argument you can deny any solar purpose. Which isn't reasonable to many use cases.
> "[...] By the same argument you can deny any solar purpose."
I don't follow. Can you expand on this line of reasoning?
Said carbon fibre is not going to save you from a 80,000lb overloaded dump truck.
I live in southern california and I drive about 20 miles a day under normal conditions.
Today I have solar panels on my house and a plug-in electric car, but I think the value proposition of a $30K car that I never need to plug in or refuel (during normal conditions) is pretty compelling. The solar panels on my home can spend time offsetting the rest of my lifestyle
I read through the absolute technical limits of solar cars once and promptly crossed the idea off in my head. Might as well just have 1000w of folding panels in your trunk that you can set out if you really need off grid charging.
Ok I'm sold on that scenario.
Kind of interesting to ponder that we might soon have car SKUs that are much more regionally localized: a car that works great in CA or AZ, but is entirely impractical for the midwest. (However, I suppose that describes 'convertibles' pretty well)
Having a car that can gradually recharge itself over the day can actually save hundreds of dollars per month (my last bill was like $600), without having to deal with the hassle of installing rooftop solar and having to pay extra money just for having solar installed [1].
https://pv-magazine-usa.com/2022/11/04/california-set-to-rel...
The main value proposition I see is an urban renter or someone with only outdoor parking (who also drives less than a suburbanite) only needing to seek out a charger once a month (or maybe not at all during summer). It also lowers grid load from this demographic that would otherwise charge over short durations by 30-80%.
The presenter is in Sydney, he's got a large roof-mounted solar array - 8kw peak output, and about 8x the area of the cells on the car. And he still struggles to cover a 25-30km daily commute with solar, achieving it only 80-90% of the time.
And good luck parking your car somewhere that gets more sun than a rooftop installation in Sydney :)
However, the Sion's $25,000 price tag is a lot better than the Lightyear Zero's $250,000 price, so they've got that going for them.
[1] https://www.youtube.com/watch?v=xIokNnjuam8
Using random numbers from Google for a Tesla 3 for an example, it has a 50kWh battery and 305 miles of range. That's 164Wh per mile. 40 miles would require 6,560Wh.
Assuming you leave the car in perfect sunlight for a full 8 hours every day, and there's no cloud, and you get 100% sunlight for the entire 8 hours, then you'd need enough panels to produce 6560Wh / 8hr or 820W.
I could probably barely fit 300W-400W worth of panels on top of my vehicle, and that's with covering the hood, trunk, roof, everything.
So even in the MOST IDEAL possible scenario, where you have your car in perfect sunlight for 8 hours a day, you're not even half way to producing 40 miles per day.
It also has about 40% less Cd, half the frontal area, much less powerful motors nd a fraction of the weight. Which is how you get from 8 hours of sunlight to 5.
Real world it's probbably more like 20-30mi
The most likely reason it won't become common is it's legally a motorcycle to get the weight down to something sensible (or has no legal category in some areas) because cars are a regulatory captured nightmare and we're literally not even allowed to have a sane sized vehicle.
The lightyear and sion are much closer to vaporware and their marketing departments are doing the concept a great disservice, but they have over a kW of panels and you could reasonably expect them to be mostly self charging if your commute is short or it's just for errands.
"investors with poor understanding of technology". You didnt even bother to read the article. Its actually:
_ “ideal conditions”; that comes out to 10 to 20 miles per day, which is near negligible _
More widely for EV, there is no need to worry how much charge you lose when parked for long periods. Not needing to worry about running the heater or AC during a traffic jam. Being less dependent on the electric grid during a natural disaster is an edge case, but still very real. Less real but still marketable is the prepper end of civilization argument.
And of course long term things start looking even more interesting as panels improve.
Right now nobody is going to heavily invest in solar car R&D, but if this becomes a common feature the simple desire for longer solar ranges is going to push efficiency.
https://sonomotors.com/site/assets/files/1621/informationssh...
Though the reason they mention it is still valid even if they might be a scam.
Much work is being done to commercialise hybrid tandem cells with growing confidence they'll be here this decade. You could similarly say "polyjunction cells have been about 32% in the lab since the 90s" once they are dominant.
Similarly boosting coverage ratios from the 70% of painted area or so of the current three concepts to 95% is possible now but not economic. As are thin film 10% efficient transparent cells in lieu of tinting over the side and rear windows.
A 40% improvement in car efficiency (the sion is heavy and boxy so there's room), with a 40% improvement in coverage and a 30% improvement in panel efficiency (or 50% in poor weather where it matters) would take it from 'okay, I guess that kinda maybe works sometimes' to 'when was the last time I plugged it in outside of a road trip?'
"that comes out to 10 to 20 miles per day, which is near negligible if you’re trying to use the car for anything other than city errands."
10-20 miles per day is a big chunk of a commute for a lot of people. This is hardly negligible.
Even if I wanted to store my car parked on the street, I don't even know where in my neighborhood I could do that. There are trees and tall buildings that shade nearly every street for at least a substantial part of the day.
Just because it doesn't work for you personally doesn't mean it is a bad idea.
the reason i wouldn’t buy this (yet)? i’m too cheap. since i spend so little time in a car already i can’t imagine ever paying more than $10k for one. by the time this model hits the used market i assume the solar efficiency and battery capacity will be about half what it is new, which might be too limiting for me. maybe future revisions will improve enough to counter that... or maybe the initial market is too small that they won’t be able to overcome that initial hurdle and build out.
but the product idea has some merit: i still wouldn’t write it off entirely the way a lot of people here are.
In the UK there's a large number of people that do not have dedicated parking (24.6%, or 6,642,000, of UK households [1]) making it more difficult to charge at home and benefit from reduced electricity prices through smart charging. If the cost of an EV with solar panels is comparable to other EVs this would help alleviate some of the issues faced by this set of drivers.
1: https://www.field-dynamics.co.uk/25-drivers-no-off-street-pa...
Okay, so there's a new solar cell that is slightly better and perhaps can be manufactured a little cheaper. Great! So what? You have failed to take into account the burden of energy storage. The capacity factor for solar is an abysmal ~20% if not ~10% in some localities. Wind can have a superior capacity factor of up to ~50%. Energy storage is the constraint.
PWRs can provide about 30% of world electricity and that same low grade heat and then you run out of Uranium. It also requires overprovision or storage for fluctuating demand and planned downtime and has correlated failures on the order of weeks or months. A capacity factor of <50% of the french fleet this yeae with unplanned correlated outages of 3 months during winter is far worse than new offshore wind with 65% forecastable output that fluctuates daily.
Even with current storage technologies the nuclear option costs more than adding enough storage to cover the next 30% with renewables.
Also your initial conceit was putting a solar panel on a 1 week battery to suppliment its input by a few miles a day. The constraint here is efficiency, daily mileage, travel velocity and area. You're welcome to keep bringing up boring predictable reactionary lies (I'm guessing something about density while ignoring the difference between fertile and fissile is next, then MOX, then breeders, then sea mining, then lies about mining), but this point has been fully addressed.
Won't happen anytime soon. There's a lot. We have a century's worth, and the uranium price could easily be three times higher, without hardly an impact to utilities, and unlock more reserves and exploration.
> capacity factor of <50% of the french fleet
This not an indictment of nuclear power as a whole. American nuclear reactors have a ~90% capacity factor.
https://www.eia.gov/energyexplained/nuclear/data-and-statist...
> Cheap storage like thermal (so the cheapest sand)
Won't be effective for producing electricity. Might only be ~30% efficient.
> far worse than new offshore wind
Wind is reasonable but don't forget that reactors can last a ridiculously long time ~75 years. Wind turbines might only last ~20 years in a corrosive environment.
> Won't happen anytime soon. There's a lot. We have a century's worth, and the uranium price could easily be three times higher, without hardly an impact to utilities, and unlock more reserves and exploration.
A century at 300GW. Quadruple that and it's 25 years. Replace 2/3rds of electricity and it's under 20. And those are reserves at a price 3 times higher. New lower level reserves will be even more expensive to the point where the LCOE of solar is around the raw uranium price.
> Won't be effective for producing electricity. Might only be ~30% efficient.
...Which is why I suggested it for the 20-30% of primary energy that is low grade heat where it is 100% efficient.
> This not an indictment of nuclear power as a whole. American nuclear reactors have a ~90% capacity factor.
If you want the anomalous US reliability, then you can't pretend you're going to pay historic french or japanese prices. Also what's the capacity factor of US nuclear reactors where construction started this century?
> Wind is reasonable but don't forget that reactors can last a ridiculously long time ~75 years. Wind turbines might only last ~20 years in a corrosive environment.
When individual unplanned repairs, or regular planned maintenance for a decade, or mid life refurbs cost more than an entire new wind turbine, this is a massive downside, not an upside. Pre-paying for 75 years worth of electricity rather than 25 means you can only build out a third of the capacity (or a twelfth given the much higher user facing cost per kWh even if you can find the cash to keep hiding the larger hidden costs)
But before you can start gaslighting about the economics you have to demonstrate that it's physically possible. Which you have not done.
Nuclear can make a small contribution, but it cannot meet the scale of renewables.
No. From the World Nuclear Association, "doubling the uranium price (say from $25 to $50 per lb U3O8) takes the fuel cost up from 0.50 to 0.62 ¢/kWh, an increase of one-quarter, and the expected cost of generation of the best US plants from 1.3 ¢/kWh to 1.42 ¢/kWh (an increase of almost 10%)."
Uranium could easily be $300/lb and nuclear will still be competitive.
> Pre-paying for 75 years worth of electricity rather than 25
Yeah, "electricity" which is intermittent and currently requires Russian and Qatari natgas to load balance... or perhaps you can re-open some coal mines. Pick your poison.
> Uranium could easily be $300/lb and nuclear will still be competitive.
$300/lb is $14/MWh which would put it precisely a dollar above the PPA price of recent indian and mexican solar projects in the current fleet, or $10/MWh which is projected 2025 prices in a high burnup reactor. Ie. Raw Uranium alone would cost more than renewables total cost whilst still only making up a quarter of the marginal costs and a tenth of the total cost.
> Yeah, "electricity" which is intermittent and currently requires Russian and Qatari natgas to load balance... or perhaps you can re-open some coal mines. Pick your poison.
Replacing 50% of electricity and 30% of primary energy without any electrical storage at all is still double what is possible with nuclear which will require that gas and coal to be running 24/7. 4 hour storage and more variable loads (like replacing fossil ammonia) can push this up to quadruple the maximum physically possible contribution from PWRs.
Also before you start gaslighting about storage you need to demonstrate that PWRs can do better than renewables with no storage if the PWR has 0 capex or build time, or that nuclear doesn't need 4 hour storage for meeting variable loads. Which you haven't.
times solar gets maybe 200 watts per square meter = 1.4kw.
times 6 hours of full solar (if you are lucky) = 8.4kwh.
divided tesla model 3 gets 2.4 kwh per mile (per below) ~ 4 miles range?
https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform...
i've edited to reflect your numbers. still feels low, but: a model 3 long range has ~ 300 miles of range on an 85kwh battery, so 3.5 miles per kwh?
Very good panels are 24%. A reasonable capacity factor for something car shaped is 10%
So about 20 miles/day in an open parking spot.
More realistically there's probably a lot of spaces you couldn't fit a panel on, so maybe 10-15mi/day reliably in most places. Enough to significantly reduce charging for a moderate commute and errand runner or eliminate it during summer.
I'd be a bit sceptical of their claims of reaching similar with polymer cells with such a boxy car though.