Michael,

My panels can be adjusted between 7 to 30 degrees. I need wrenches and some help to change angle. The offset of sun to panel angle is small, going back and forth between those two angles. So basically I have a summer and winter tilt only. I'm at a 31 degree latitude.

That is a BRILLIANT installation. Hard to believe it is DIY.

Michael, you obviously know your stuff and have thought through this project way more than I ever could. You make me doubt my conclusions about one axis tilting to match the sun's inclination.

I used pvwatts to estimate how close a manual tilt 4 times a year would come to daily continuous, and IIRC I thought > 90% of ideal collection would be achieved with manual. What do your numbers and calcs say ?

I am unhappily surprised to hear the price you paid. I thought panels were under $1/watt these days; from your post it sounds like you paid closer to $4/watt.

Ugh, I lost my post.
Here is a recreated spreadsheet that uses PVWatts to check insolation using various tilt strategies. I get that 4 season manual N-S adjustment is ~ 92.5% of continuous N-S.

Sound about right, Michael ?

Hello ELGo, Thanks for your kind words. No one was more disappointed than I was to pay $4 per watt for our installation, but I just read an article that reported that the average installation of residential or small commercial solar arrays in 2011 was pegged at $6.10 per watt. That's when ours first went online. My numbers, as you call them, are a dimly remembered event from three to four years ago, so I can't answer your questions with any degree of certitude, but I'd agree with your figures. I plan to build a smaller, seasonally adjusted array in the near future and consider it good enough. mm

I envy you :thumbup:

If your smaller array could take advantage of E-W tilting, your DIY skills would really pay off.

What is your estimated $/watt for this new array ?

I poked around on the web a little, and came up with:
$1/watt panels
$0.70/watt Enphase inverter
$0.50/watt manual tilting support to put on the end of a pole

This is a sweet... install it looks great.