Solar experiment: effect of tilting panels

[acadiaforever]

I've heard lots of estimates of the effect of tilting solar panels or not. The estimates of the percentage of energy capture lost by leaving them flat varied all over the place. 25%... 30%...

When we went to the Quartzsite rally, I decided that I wouldn't tilt. We were only going to be there a few days, and it is a pain to go up and tilt, and then lay them flat when it is time to travel again. But after the first day, I was really dissatisfied with the system's performance when flat.

So here is one data point. Your mileage may vary, of course.

Date: Jan 10; therefore the sun is near its lowest point in the sky.
Time: near 12:00 noon clock time, slightly before solar noon at 12:44 today. Measurements were taken approximately 20 minutes apart.
Weather: A beautiful clear day, no clouds to interfere with measurements.
Controllers: 2 x Blue Sky MPPT.

Amps out of the controllers, flat: 32.4,
Amps out of the controllers, tilted: 65.2.

That is approximately a doubling of the energy capture by tilting the panels. Or in terms of energy capture lost by leaving them flat, fully 50%.

Even tilted, my panels are not perpendicular to the sun this near the solstice, but I'm happy. And I'll not use them flat during the winter again.

[Ditchdigger]

They say if you want to leave them flat you need to double the the panels. It depends on how fast you want your batteries to recover, and how much you use during the day. Atnight it is your batteries that counts.

[ExtremeDuty]

Excellent! Thanks for that. If we can ever arrange to actually head south for the Winter I'll have my tilt bars in hand. As for now, I don't care with it stored alongside the shop.