3 ms·

I don't drive to work, but 2 miles per hour would be crazy good for me, as I live inside a city and my total commute is exactly 18 miles, which would mean my co

by raducu 7y ago

I don't drive to work, but 2 miles per hour would be crazy good for me, as I live inside a city and my total commute is exactly 18 miles, which would mean my commute would be "free" (not taking into account the cost of the panels or the vehicle).

adrianN 7y ago
It's also unrealistically good as you don't get high noon insolation for 9 hours a day.
- Retric 7y ago
  You do however get some power for more than 9 hours per day. Also, panels can go well past 200w/m at a theoretically possible 600w/m the numbers look rather different. Cars are only going 12-15k miles a year so hit 40miles a day and you generally stop needing charging stations.
  - jartelt 7y ago
    The amount of power incident from the sun is roughly 1000 W/m^2 in a sunny area. Good Silicon PV panels will capture 20% of that power generating 200 W/m^2 at peak. Getting anything more than that is going to be too expensive for a car application. Pulling 600 W/m^2 from a PV panel may be theoretically possible, but the world record efficiency for a PV device is still less than 50%. To get above 40% efficiency you need to use very expensive multijunction devices and solar concentrators (i.e. not going to work on a car).
    - Retric 7y ago
      I generally agree today, but that says little about the long term. As solar panels have gotten cheaper installation costs have become more important which has pushed up panel efficiency. Cheap but good panels are up to ~23% efficiency where they where ~18% fairly recently. What’s interesting is these trends seem to be continuing with serious research into various affordable multi junction cells going on.
forgot-my-pw 7y ago
That means it has to sit directly under the sun all the time. If you get the plugin Prius, you can already not pay for gas at all with short commutes. And it cost almost half of Tesla Model 3.
- drawkbox 7y ago
  Yeah how many people want to park their car in the sun all day long? The better way is parking it in a garage of small to large size, that has solar on the roof, with a much bigger surface area, that you could plug into. Another bad part is that since solar is still in heavy innovation phases, you'd need to be able to swap out panels for replacement and newer tech so there would need to be standards there or else it becomes highly cost prohibitive. It would add so much to testing that it would add layers of cost. This would also limit design options and weight. Even when efficient, you still want to park your car in or under a cover/garage. That is the best place to put the panels because noone wants a hot car.

by raducu 7y ago

adrianN 7y ago

It's also unrealistically good as you don't get high noon insolation for 9 hours a day.

Retric 7y ago
You do however get some power for more than 9 hours per day. Also, panels can go well past 200w/m at a theoretically possible 600w/m the numbers look rather different. Cars are only going 12-15k miles a year so hit 40miles a day and you generally stop needing charging stations.
- jartelt 7y ago
  The amount of power incident from the sun is roughly 1000 W/m^2 in a sunny area. Good Silicon PV panels will capture 20% of that power generating 200 W/m^2 at peak. Getting anything more than that is going to be too expensive for a car application. Pulling 600 W/m^2 from a PV panel may be theoretically possible, but the world record efficiency for a PV device is still less than 50%. To get above 40% efficiency you need to use very expensive multijunction devices and solar concentrators (i.e. not going to work on a car).
  - Retric 7y ago
    I generally agree today, but that says little about the long term. As solar panels have gotten cheaper installation costs have become more important which has pushed up panel efficiency. Cheap but good panels are up to ~23% efficiency where they where ~18% fairly recently. What’s interesting is these trends seem to be continuing with serious research into various affordable multi junction cells going on.

forgot-my-pw 7y ago

That means it has to sit directly under the sun all the time. If you get the plugin Prius, you can already not pay for gas at all with short commutes. And it cost almost half of Tesla Model 3.

drawkbox 7y ago
Yeah how many people want to park their car in the sun all day long? The better way is parking it in a garage of small to large size, that has solar on the roof, with a much bigger surface area, that you could plug into. Another bad part is that since solar is still in heavy innovation phases, you'd need to be able to swap out panels for replacement and newer tech so there would need to be standards there or else it becomes highly cost prohibitive. It would add so much to testing that it would add layers of cost. This would also limit design options and weight. Even when efficient, you still want to park your car in or under a cover/garage. That is the best place to put the panels because noone wants a hot car.