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Not exactly a fair comparison as it doesn't appear to be counting the generation of the electricity for the EV. However, EV's still win by a large margin. It's

Not exactly a fair comparison as it doesn't appear to be counting the generation of the electricity for the EV. However, EV's still win by a large margin. It's a lot easier to make one big powerplant clean, efficient, and cost effective rather than a million little engines that have to make tradeoffs for weight/size/performance etc...

ravi-delia 6y ago
Plus you can power an electric car with solar panels as long as it doesn't have to carry them around. Over time the grid will become more and more green, while gas cars will always have to burn their fuel.
- ben_w 6y ago
  In principle you can carry the panels with the car. How useful that is in practice will have to wait for this to actually be released, and this model in particular can’t even in principle serve anyone who drives even a little more than 89% of the miles per year of the mean US driver (12k/13.8k = 88.888…%), but in principle cars can take their PV with them: https://www.topgear.com/car-news/electric/lightyear-one-long-range-solar-powered-ev https://www.topgear.com/car-news/electric/lightyear-one-long...
  - raws 6y ago
    But given the right size and efficiency for a panel, a big rollable panel could give you power anywhere in the world which fuel cars could never do.
    - giobox 6y ago
      Not really, as we know the max theoretical power output of solar on earth. Given we know that generally best sun can do is approximately 1kw/square meter, Assuming you had 100 percent efficient conversion (we aren't close to that even with best solar panels today), we know its never going to be great for charging cars who have large energy requirements. Even in the best possible case, very few people are going to charge a car directly from their own private solar source unless no other choices, it's just not remotely time efficient and likely never will be. To charge an empty 75kwh car battery in roughly 1 hr today you would need approximately 225 square meters of solar panel, assuming a pretty good ~30 percent efficiency rate and strong sun. In reality it will likely need even more panels, and this is all before you contend with shade, weather, night storage and so forth. For a car, private solar will likely never work well enough to become mainstream due to aforementioned solar energy transmission limits.
      - _ph_ 6y ago
        If you have the solar cells with your car, you don't need to charge the whole battery in one hour. You have to recharge during one day what you are using in your daily driving. Which is of course much less. In Germany a car drives less than 50 kilometers per day on average, so that is less than 10 kWh per day.
        giobox 6y ago
        12 hours of sun, the best you can hope for any time soon is about 3kwh put back into the car. In other words, a few miles of range can be restored. There is a reason no car manufacturer is currently seriously pursuing solar roofs - it's just too small a surface area to generate meaningful energy in a car context. The math doesn't work. We might see systems (as we've seen in past) where solar helps power accessories on the 12v system (AC/in car entertainment etc), but its not going to meaningfully affect range of the vehicle or help top up the traction battery.
        ben_w 6y ago
        > 12 hours of sun, the best you can hope for any time soon is about 3kwh put back into the car. In other words, a few miles of range can be restored. Horizontal solar radiation is 3 kWh/m^2/day, in Germany. 5 m^2 of PV on the car in the article I linked to. 0.25-ish wH/mile is roughly what Teslas get. That works out as 60 miles times the cell efficiency per day, call it 12-24 miles in practice with 20-40% efficient cells. Matches the article pretty well, considering how far north Germany is. > no car manufacturer is currently seriously pursuing solar roofs I literally linked to a car manufacturer doing just that :P
        giobox 6y ago
        > I literally linked to a car manufacturer doing just that :P You literally linked to a car tech startup whose unproven prototype technology has shipped in exactly zero production cars, yes ;) There is no car manufacturer doing this meaningfully today, and again likely won't be soon.
      - 6y ago
- Fjolsvith 6y ago
  Some armchair math: Energy required to fully charge a Tesla: 50kwh [1] Average electricity output from solar: 200w/meter squared [2] 50000/200 = 250 square meters of solar for 1 hour 250/8 = 31.5 square meters of solar for 8 hours (typical day) Number of cars on the planet: 1.42 billion [3] 1.42b * 31.5 = 44.375 billion square meters of solar needed to recharge all the cars on the planet, if they were all charging at the same time. Total cost for just the solar panels: $177 billion [4] Not to mention the land purchase and infrastructure investment to carry that much extra electricity every day. 1. https://www.motorbiscuit.com/how-much-does-it-cost-charge-tesla/ https://www.motorbiscuit.com/how-much-does-it-cost-charge-te... 2. https://www.theecoexperts.co.uk/solar-panels/how-much-electricity#:~:text=The%20standard%20solar%20panel%20has,150%2D200W%20in%20good%20sunlight https://www.theecoexperts.co.uk/solar-panels/how-much-electr.... 3. https://www.rfidtires.com/how-many-cars-world.html#:~:text=Presently%2C%20there%20are%201.42%20billion,and%20363%20million%20commercial%20vehicles https://www.rfidtires.com/how-many-cars-world.html#:~:text=P.... 4. https://www.solarpowerfam.com/cost-of-solar-panels-per-square-meter/ https://www.solarpowerfam.com/cost-of-solar-panels-per-squar... $4 for best cost.
  - maxerickson 6y ago
    So that's an argument in favor of it then?
  - tmellon2 6y ago
    However most cars in the world do not drain a whole charge each day (i.e.) only a small percentage of the 1.42 billion cars will drive 300 miles each day ! Besides, home roof solar can easily charge small EV cars. Please see this story : https://restofworld.org/2021/tesla-vs-tiny-cars/ https://restofworld.org/2021/tesla-vs-tiny-cars/
- traveler01 6y ago
  Funny that nobody even considers the health issues of always having these exaust pipes spewing out toxic fumes... EVs are just better and more green, don't even know how's that a question.
JulianMorrison 6y ago
I think re: power generation as such, that the important point with EVs is that they decouple the car from the particular details of how it's powered. Electricity is fungible, and power generation can become more green without needing to tinker with the inner workings of the cars that use it.

ravi-delia 6y ago

Plus you can power an electric car with solar panels as long as it doesn't have to carry them around. Over time the grid will become more and more green, while gas cars will always have to burn their fuel.

ben_w 6y ago
In principle you can carry the panels with the car. How useful that is in practice will have to wait for this to actually be released, and this model in particular can’t even in principle serve anyone who drives even a little more than 89% of the miles per year of the mean US driver (12k/13.8k = 88.888…%), but in principle cars can take their PV with them: https://www.topgear.com/car-news/electric/lightyear-one-long-range-solar-powered-ev https://www.topgear.com/car-news/electric/lightyear-one-long...
- raws 6y ago
  But given the right size and efficiency for a panel, a big rollable panel could give you power anywhere in the world which fuel cars could never do.
  - giobox 6y ago
    Not really, as we know the max theoretical power output of solar on earth. Given we know that generally best sun can do is approximately 1kw/square meter, Assuming you had 100 percent efficient conversion (we aren't close to that even with best solar panels today), we know its never going to be great for charging cars who have large energy requirements. Even in the best possible case, very few people are going to charge a car directly from their own private solar source unless no other choices, it's just not remotely time efficient and likely never will be. To charge an empty 75kwh car battery in roughly 1 hr today you would need approximately 225 square meters of solar panel, assuming a pretty good ~30 percent efficiency rate and strong sun. In reality it will likely need even more panels, and this is all before you contend with shade, weather, night storage and so forth. For a car, private solar will likely never work well enough to become mainstream due to aforementioned solar energy transmission limits.
    - _ph_ 6y ago
      If you have the solar cells with your car, you don't need to charge the whole battery in one hour. You have to recharge during one day what you are using in your daily driving. Which is of course much less. In Germany a car drives less than 50 kilometers per day on average, so that is less than 10 kWh per day.
      - giobox 6y ago
        12 hours of sun, the best you can hope for any time soon is about 3kwh put back into the car. In other words, a few miles of range can be restored. There is a reason no car manufacturer is currently seriously pursuing solar roofs - it's just too small a surface area to generate meaningful energy in a car context. The math doesn't work. We might see systems (as we've seen in past) where solar helps power accessories on the 12v system (AC/in car entertainment etc), but its not going to meaningfully affect range of the vehicle or help top up the traction battery.
        ben_w 6y ago
        > 12 hours of sun, the best you can hope for any time soon is about 3kwh put back into the car. In other words, a few miles of range can be restored. Horizontal solar radiation is 3 kWh/m^2/day, in Germany. 5 m^2 of PV on the car in the article I linked to. 0.25-ish wH/mile is roughly what Teslas get. That works out as 60 miles times the cell efficiency per day, call it 12-24 miles in practice with 20-40% efficient cells. Matches the article pretty well, considering how far north Germany is. > no car manufacturer is currently seriously pursuing solar roofs I literally linked to a car manufacturer doing just that :P
        giobox 6y ago
        > I literally linked to a car manufacturer doing just that :P You literally linked to a car tech startup whose unproven prototype technology has shipped in exactly zero production cars, yes ;) There is no car manufacturer doing this meaningfully today, and again likely won't be soon.
    - 6y ago
Fjolsvith 6y ago
Some armchair math: Energy required to fully charge a Tesla: 50kwh [1] Average electricity output from solar: 200w/meter squared [2] 50000/200 = 250 square meters of solar for 1 hour 250/8 = 31.5 square meters of solar for 8 hours (typical day) Number of cars on the planet: 1.42 billion [3] 1.42b * 31.5 = 44.375 billion square meters of solar needed to recharge all the cars on the planet, if they were all charging at the same time. Total cost for just the solar panels: $177 billion [4] Not to mention the land purchase and infrastructure investment to carry that much extra electricity every day. 1. https://www.motorbiscuit.com/how-much-does-it-cost-charge-tesla/ https://www.motorbiscuit.com/how-much-does-it-cost-charge-te... 2. https://www.theecoexperts.co.uk/solar-panels/how-much-electricity#:~:text=The%20standard%20solar%20panel%20has,150%2D200W%20in%20good%20sunlight https://www.theecoexperts.co.uk/solar-panels/how-much-electr.... 3. https://www.rfidtires.com/how-many-cars-world.html#:~:text=Presently%2C%20there%20are%201.42%20billion,and%20363%20million%20commercial%20vehicles https://www.rfidtires.com/how-many-cars-world.html#:~:text=P.... 4. https://www.solarpowerfam.com/cost-of-solar-panels-per-square-meter/ https://www.solarpowerfam.com/cost-of-solar-panels-per-squar... $4 for best cost.
- maxerickson 6y ago
  So that's an argument in favor of it then?
- tmellon2 6y ago
  However most cars in the world do not drain a whole charge each day (i.e.) only a small percentage of the 1.42 billion cars will drive 300 miles each day ! Besides, home roof solar can easily charge small EV cars. Please see this story : https://restofworld.org/2021/tesla-vs-tiny-cars/ https://restofworld.org/2021/tesla-vs-tiny-cars/
traveler01 6y ago
Funny that nobody even considers the health issues of always having these exaust pipes spewing out toxic fumes... EVs are just better and more green, don't even know how's that a question.

JulianMorrison 6y ago

I think re: power generation as such, that the important point with EVs is that they decouple the car from the particular details of how it's powered. Electricity is fungible, and power generation can become more green without needing to tinker with the inner workings of the cars that use it.