Forum Discussion

HiTech's avatar
HiTech
Explorer
Jun 26, 2013

How much solar charging are you getting while driving?

Every so often someone makes the point that they get significant solar charging while driving.

For those of you that notice this, any thoughts on how much charging you are getting just from solar (vs. say alternator), and how much solar yield you are getting compared to being stationary?

What panels and controller are you using to see the result?

Jim
  • Enough to run my 2-way fridge on electric through an inverter.
    So at least 28 amps. OK maybe some comes from the truck but I don't think very much.

    I would expect better performance when rolling as the 60 mph breeze will help cool the panels.
  • HiTech wrote:
    Because of shadows from semis, buildings, bridges...etc hitting the PVs, and because of less tree cover. Also because of rapidly changing direction of illumination and most likely little tilt. But especially the very rapidly changing illumination/shadow pattern, and what different controllers might make of it. Many factors. If you look at the solar race cars, they have much more advanced control strategies than most stationary charge controllers.

    I imagine PWM would run effectively the same.

    But I am curious in what people here actually observe with their set ups.

    Jim


    This would be another fine study project that would give loads of usless information if one had nothing better to do but watch a solar panel monitor while traveling.
    After gathering all this information, what would you do with it that would be benificial?
  • I have two of these.

    This is the controller I use.

    Battery bank is two 12 volt group 24.

    When towing, I don't know how a person would tell how much power was coming from solar and how much was coming from tow vehicle, unless the tow vehicle provided no charging at all.

    Length of time a person could expect for boodocking, depends on power usage, hours of sunlight, angle of sunlight, size (and condition) of battery bank, size and type of panels, type of controller, and wire size used to hook it up.

    All my interior and exterior lights are LED, and my television is (low watt) 12 volt. No inverter to run any 120 volt appliances. We have boondocked for up to 5 days, with no noticeable drop in battery power. The solar panels kept up with a couple hours (daily) lights and television, and, all the parasitic draws from gas detector, refridgerator, etc.


    I also have a panel on my TC. It is a single 135 watt with PWM controller.

    Just out of curiosity, one sunny day, I disconnected the battery and connected the cables from the controller, directly to the converter. I was able to watch television and turn on a couple lights (also LED), with nothing but solar power.
  • Yeah, kinda an empty question ? It would depend on a lot of different circumstances. And w/ the alternator holding the system at + 14 volts, I wouldn't expect solar to put out much at all anyway.
    But my solar doesn't put out much at all while driving, because the panels are in a storage comp :)
  • Because of shadows from semis, buildings, bridges...etc hitting the PVs, and because of less tree cover. Also because of rapidly changing direction of illumination and most likely little tilt. But especially the very rapidly changing illumination/shadow pattern, and what different controllers might make of it. Many factors. If you look at the solar race cars, they have much more advanced control strategies than most stationary charge controllers.

    I imagine PWM would run effectively the same.

    But I am curious in what people here actually observe with their set ups.

    Jim
  • Why would it be any different than when you are sitting still? Maybe even better, because the roads have no trees to block the sun. When I travel, I still don't travel faster than the speed of light.

    Mike

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