How to figure monthly optimum array angles?
Now that I've installed the two MT Solar adjustable pole mounts, I'm finding it hard to get an idea of how to figure the numbers for where I'm at. The problem is, I've found 3 different formulas, so I'm not sure what is what. Surely there is a simple, correct formula for establishing monthly angles. I've found plenty for adjusting them for winter/summer and even a few that throw in fall and spring. But even on those, different people/books have different formulas. But since I've invested in these two arrays that are easily adjustable, I plan on zeroing them in every month.
The formula that seems to come up the most, after the "easy" way is explained, is (Latitude * [degrees] x 0.9) + 29* for winter, and (Latitude* x 0.9) - 23.5* for summer. These would put me at 62.8* mid-winter and 10.3* mid-summer. This seems about right, but it doesn't give me monthlies. Where can I find a page or formula to help me figure out the necessary angles. BTW, my arrays are 37.58N - 90.40W. Thanks for any help on this. Lee
"Knowing is not enough, we must apply. Willing is not enough, we must do." Goethe
NOS Trace Xantrex power panel, (3) Trace Xantrex SW5548's (2 NOS in boxes, one used), Xantrex DC/disconnect, AC disconnect/conversion, Xantrex T240 Auto transformer, (3) C40 PWM charge controllers, (2 NOS, one used) 8k LG Neon 320w, (8)Evergreen Solar 120w (960w) , Bergey XL.1 1.5k genny, AirX 400 genny, 48v Interstate Workman batts (frozen/toast), (2) MT Solar Top of Pole 12's, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's and one nice Ozark hilltop to set them all.