Solar car just toured the US, and will start production next year
singularityhub.com
singularityhub.com
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.
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
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.
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.
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.
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%.
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)
"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.
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?'
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.
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.
"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.
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.
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/
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.
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.
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...
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?
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.
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?
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.
And if you're in an area prone to drought (like places that get plenty of sun), washing your car may not even be feasible.
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.