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Solar car just toured the US, and will start production next year

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Re: Solar car just toured the US, and will start production next year

#51

Post by dougmwne »

cwkoss wrote: post #30
dougmwne wrote: post #28

Earlier quoted context omitted.

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 so…

Most renters have little control of whether they have access to an EV hookup. This opens up the market to street parkers in the right climates.

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.

Ok I'm sold on that scenario.

Re: Solar car just toured the US, and will start production next year

#52

Post by jeffbee »

Retric wrote: post #49
jeffbee wrote: post #44

Earlier quoted context omitted.

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.

https://sonomotors.com/site/assets/files/1621/informationssh...

Re: Solar car just toured the US, and will start production next year

#53

Post by rasz »

andrewmutz wrote: post #23
snickerer wrote: post #6

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 b…

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 c…

>Its a $30K car with a range of 190 miles and can charge itself 40 miles a day in optimal conditions.

"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 _

Re: Solar car just toured the US, and will start production next year

#54

Post by dreamcompiler »

bilsbie wrote: post #42
joshu wrote: post #40

a average fullsize car has approximately a 7 square meter roof. assume we get 100% of that. 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?

The model 3 is around 2.4 kWh per mile. Plus if you get some fold out panels you could at least double that surface area. Now we’re talking 20 miles. https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform...

Nope. It's 0.24 kWh per mile.

Re: Solar car just toured the US, and will start production next year

#55

Post by dreamcompiler »

joshu wrote: post #40

a average fullsize car has approximately a 7 square meter roof. assume we get 100% of that. 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?

No car has a 7 square meter roof. 1 square meter would be common, but not 7.

Re: Solar car just toured the US, and will start production next year

#56

Post by ttfkam »

Grim-444 wrote: post #47
andrewmutz wrote: post #23

Earlier quoted context omitted.

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 c…

"can charge itself 40 miles a day in optimal conditions." 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…

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.

Re: Solar car just toured the US, and will start production next year

#57

Post by porphyra »

dougmwne wrote: post #50
porphyra wrote: post #35

Earlier quoted context omitted.

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 insta…

Right but what's the problem with plugging into the solar panels that stay in place?

1. you can charge at work 2. having solar panels that stay in place might cost money per month, as per the link in my last comment

Re: Solar car just toured the US, and will start production next year

#58

Post by ranguna »

ttfkam wrote: post #56
Grim-444 wrote: post #47

Earlier quoted context omitted.

"can charge itself 40 miles a day in optimal conditions." 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…

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.

Do you have a wh/km to backup your claim?

Re: Solar car just toured the US, and will start production next year

#59

Post by Retric »

jeffbee wrote: post #52
Retric wrote: post #49

Earlier quoted context omitted.

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. https://sonomotors.com/site/assets/files/1621/informationssh...

Ahh, fair enough the pride seemed unreasonably low.

Though the reason they mention it is still valid even if they might be a scam.

Re: Solar car just toured the US, and will start production next year

#60

Post by Schroedingersat »

kdbeall_ wrote: post #38

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.
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