16 ms·

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

35 points by cheinyeanlim 4y ago

mysterydip 4y ago
Solar panels as (essentially) bodywork seems like it would be less than ideal in actual use. Fender bender? Car got dirty?
- yakak 4y ago
  Seems like things car owners worry about no matter what; even if the materials have no possibility of output.
  - kQq9oHeAz6wLLS 4y ago
    Yeah, but instead of "meh, I'll wash the car tomorrow" and just drive a dirty car, you get diminished range. 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.
    - Schroedingersat 4y ago
      You don't have to get the hose out just to make it transmit 90% of the light. 2 liters in a bowl is plenty.
- rangersanger 4y ago
  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.
  - bogwog 4y ago
    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.
- incomingpain 4y ago
  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. 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 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?
  - Schroedingersat 4y ago
    > 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.
cjtrowbridge 4y ago
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.
- anamexis 4y ago
  How are people traveling the world with "up to 40 miles per day in optimal sun conditions"?
  - kQq9oHeAz6wLLS 4y ago
    They didn't say how long it would take...
    - cjtrowbridge 4y ago
      Recouping daily commutes with solar is trivial.
  - MichaelCollins 4y ago
    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.
    - colinsane 4y ago
      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.
snickerer 4y ago
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.
- incomingpain 4y ago
  >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.
  - eloff 4y ago
    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.
  - MichaelCollins 4y ago
    > > 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?
hailmike 4y ago
What a biased article: "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.
- MichaelCollins 4y ago
  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.
  - qqqwerty 4y ago
    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.
  - TaylorAlexander 4y ago
    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.
colinsane 4y ago
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.
kieranmaine 4y ago
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. 1: https://www.field-dynamics.co.uk/25-drivers-no-off-street-parking/ https://www.field-dynamics.co.uk/25-drivers-no-off-street-pa...
kdbeall_ 4y ago
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.
- Schroedingersat 4y ago
  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.
  - kdbeall_ 4y ago
    > 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.
    - Schroedingersat 4y ago
      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.
joshu 4y ago
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?
- bilsbie 4y ago
  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&year1=2020&year2=2020&make=Tesla&baseModel=Model%203&srchtyp=ymm https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform...
  - joshu 4y ago
    that's still 3 miles range without the foldout. also the hours of light are very optimistic at best. i'm assuming full output for 6 hours in a a row. 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?
  - dreamcompiler 4y ago
    Nope. It's 0.24 kWh per mile.
- dreamcompiler 4y ago
  No car has a 7 square meter roof. 1 square meter would be common, but not 7.
  - joshu 4y ago
    I was being very, very generous and converted average length times average width. One or two square meters tops is more reasonable.
- Schroedingersat 4y ago
  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.
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pulvinar 4y ago
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.
deleted 4y ago
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35 points by cheinyeanlim 4y ago

Solar panels as (essentially) bodywork seems like it would be less than ideal in actual use. Fender bender? Car got dirty?

yakak 4y ago
Seems like things car owners worry about no matter what; even if the materials have no possibility of output.
- kQq9oHeAz6wLLS 4y ago
  Yeah, but instead of "meh, I'll wash the car tomorrow" and just drive a dirty car, you get diminished range. 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.
  - Schroedingersat 4y ago
    You don't have to get the hose out just to make it transmit 90% of the light. 2 liters in a bowl is plenty.
rangersanger 4y ago
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.
- bogwog 4y ago
  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.
incomingpain 4y ago
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. 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 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?
- Schroedingersat 4y ago
  > 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.

cjtrowbridge 4y ago

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.

anamexis 4y ago
How are people traveling the world with "up to 40 miles per day in optimal sun conditions"?
- kQq9oHeAz6wLLS 4y ago
  They didn't say how long it would take...
  - cjtrowbridge 4y ago
    Recouping daily commutes with solar is trivial.
- MichaelCollins 4y ago
  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.
  - colinsane 4y ago
    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.

snickerer 4y ago

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.

incomingpain 4y ago
>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.
- eloff 4y ago
  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.
- MichaelCollins 4y ago
  > > 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?

hailmike 4y ago

What a biased article: "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.

MichaelCollins 4y ago
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.
- qqqwerty 4y ago
  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.
- TaylorAlexander 4y ago
  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.

colinsane 4y ago

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.

kieranmaine 4y ago

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. 1: https://www.field-dynamics.co.uk/25-drivers-no-off-street-parking/ https://www.field-dynamics.co.uk/25-drivers-no-off-street-pa...

kdbeall_ 4y ago

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.

Schroedingersat 4y ago
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.
- kdbeall_ 4y ago
  > 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.
  - Schroedingersat 4y ago
    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.

joshu 4y ago

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?

bilsbie 4y ago
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&year1=2020&year2=2020&make=Tesla&baseModel=Model%203&srchtyp=ymm https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform...
- joshu 4y ago
  that's still 3 miles range without the foldout. also the hours of light are very optimistic at best. i'm assuming full output for 6 hours in a a row. 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?
- dreamcompiler 4y ago
  Nope. It's 0.24 kWh per mile.
dreamcompiler 4y ago
No car has a 7 square meter roof. 1 square meter would be common, but not 7.
- joshu 4y ago
  I was being very, very generous and converted average length times average width. One or two square meters tops is more reasonable.
Schroedingersat 4y ago
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.

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pulvinar 4y ago

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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