solar panel output vs. tilt angle
I'm working on a pole mount for my portable panels so that when the trailer is in direct sun, or getting the panels 10' or so in the air gets good sun I can put them on the pole instead of on the grou...
Forum Discussion
I have some experience with this. The situation is that at noon there is a proper tilt angle for the panel facing South that you can calculate when you know the sun's declination and your latitude.
That tilt angle changes by about 46 degrees over six months, so the average change is 8 degrees a month, but it is not linear month to month.
Meanwhile, the sun is lower the rest of the day, so the panel needs to be tilted higher when pointing at the sun earlier and later than noon. So the compromise for a fixed tilt on a rotating contraption is higher than for noon but not forgetting that most of the daily AH haul is mid-morning to mid afternoon so you shouldn't have it way up for best early morning late afternoon angle. Something more but not a lot higher tilt than for noon is the best compromise.
So that still leaves the problem of when in the year is this for? All year or just the summer or when? You need to find a compromise proper tilt for noon in that period of use, so you can then pick a tilt higher than that.
Note---for a fixed tilt South, non rotating panel, it is the opposite situation. You want the tilt less than for noon so it can catch light better earlier and later. Macslab has some numbers for that.
I didn't work too hard to find a best tilt angle for the period mid April to mid September for 49.2N but where the best angle for noon was 40 I would make the tilt no more than 50. You get about 10 degrees of play before you lose amps much so that did pretty well.
I found changing the swivel aim three times a day was sufficient, SE S , and SW (putting it back to SE at sunset) If you did have an adjustable tilt to go with the swivel you would have two positions. One lower at S and one higher for SE and SW.
That tilt angle changes by about 46 degrees over six months, so the average change is 8 degrees a month, but it is not linear month to month.
Meanwhile, the sun is lower the rest of the day, so the panel needs to be tilted higher when pointing at the sun earlier and later than noon. So the compromise for a fixed tilt on a rotating contraption is higher than for noon but not forgetting that most of the daily AH haul is mid-morning to mid afternoon so you shouldn't have it way up for best early morning late afternoon angle. Something more but not a lot higher tilt than for noon is the best compromise.
So that still leaves the problem of when in the year is this for? All year or just the summer or when? You need to find a compromise proper tilt for noon in that period of use, so you can then pick a tilt higher than that.
Note---for a fixed tilt South, non rotating panel, it is the opposite situation. You want the tilt less than for noon so it can catch light better earlier and later. Macslab has some numbers for that.
I didn't work too hard to find a best tilt angle for the period mid April to mid September for 49.2N but where the best angle for noon was 40 I would make the tilt no more than 50. You get about 10 degrees of play before you lose amps much so that did pretty well.
I found changing the swivel aim three times a day was sufficient, SE S , and SW (putting it back to SE at sunset) If you did have an adjustable tilt to go with the swivel you would have two positions. One lower at S and one higher for SE and SW.
