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Your math is way off. A single PV produces between 300-400 watts at peak sun. It takes ~300 watt hours to drive an EV 1 mile. A very good sunny location gets 6-

by jtc331 4y ago

Your math is way off. A single PV produces between 300-400 watts at peak sun. It takes ~300 watt hours to drive an EV 1 mile. A very good sunny location gets 6-7 peak sun hours equivalent a day. So that one panel gets you 6-7 miles of EV range a day. A typical house needs probably 15-20 panels to produces it’s needs (assuming you have storage) before EVs are even in the picture.

bluGill 4y ago
The average car goes about 40 miles per day (https://www.bts.gov/statistical-products/surveys/national-household-travel-survey-daily-travel-quick-facts https://www.bts.gov/statistical-products/surveys/national-ho...), so by your numbers only 40/6=7 panels are needed per car to charge, with some extra capacity. I think every garage as enough space on the roof for that many (per car inside), and still have extra space. Of course most cars are not at home all day, and cloudy days have to be accounted for. So we have to assume some sort of system to get around that. (the obvious ones are battery at home to charge, or sell to the grid at home and buy from the grid where you are charging) Solving these problems is not easy, but the math works out that you can do it.
- Quarrel 4y ago
  > The average car goes about 40 miles per day Is not what your link says, it says: > U.S. daily travel averages 11 billion miles a day — almost 40 miles per person per day Which is a different metric. Perhaps more pertinent is: > (The Average Driver) Drives 29 miles a day
  - bluGill 4y ago
    I stand corrected. (I just read the ddg summary blurb not the whole thing) That just makes solar on a garage more feasible though.
- masklinn 4y ago
  It’s also underselling “very good sunny location”: in a really sunny state like AZ you can expect ~2.7kWh/day, which assuming 300Wh/mi is 9 miles per panel per day (or better for a more efficient EV e.g. the model 3 is around 240Wh/mi, Lightyear 0 claims an incredible 175Wh/mi).
  - bluGill 4y ago
    Sure, but AZ is about the best possible case for solar. Most of us don't live there and so need more conservative numbers.
    - masklinn 4y ago
      > Sure, but AZ is about the best possible case for solar. Most of us don't live there and so need more conservative numbers. Your qualification of your numbers was > very good sunny location not > some random unspecified location

by jtc331 4y ago

bluGill 4y ago

The average car goes about 40 miles per day (https://www.bts.gov/statistical-products/surveys/national-household-travel-survey-daily-travel-quick-facts https://www.bts.gov/statistical-products/surveys/national-ho...), so by your numbers only 40/6=7 panels are needed per car to charge, with some extra capacity. I think every garage as enough space on the roof for that many (per car inside), and still have extra space. Of course most cars are not at home all day, and cloudy days have to be accounted for. So we have to assume some sort of system to get around that. (the obvious ones are battery at home to charge, or sell to the grid at home and buy from the grid where you are charging) Solving these problems is not easy, but the math works out that you can do it.

Quarrel 4y ago
> The average car goes about 40 miles per day Is not what your link says, it says: > U.S. daily travel averages 11 billion miles a day — almost 40 miles per person per day Which is a different metric. Perhaps more pertinent is: > (The Average Driver) Drives 29 miles a day
- bluGill 4y ago
  I stand corrected. (I just read the ddg summary blurb not the whole thing) That just makes solar on a garage more feasible though.
masklinn 4y ago
It’s also underselling “very good sunny location”: in a really sunny state like AZ you can expect ~2.7kWh/day, which assuming 300Wh/mi is 9 miles per panel per day (or better for a more efficient EV e.g. the model 3 is around 240Wh/mi, Lightyear 0 claims an incredible 175Wh/mi).
- bluGill 4y ago
  Sure, but AZ is about the best possible case for solar. Most of us don't live there and so need more conservative numbers.
  - masklinn 4y ago
    > Sure, but AZ is about the best possible case for solar. Most of us don't live there and so need more conservative numbers. Your qualification of your numbers was > very good sunny location not > some random unspecified location