calculating north tilt vs afternoon tree shading

[bcroe]

Forgot to add. I tried to buy a used S. P. F. or rent one but could not find either.

I saw several on Eb*y, search solar pathfinder. Bruce Roe

[Yogi6262]

It depends on where you relocated, but based on 41.7 north (Chicago), 1K of panels at 10 degrees tilt facing north is 1,036 Kwh a year. Facing south is 1,223 kwh. Not a HUGE difference. But you would have to have complete shading from November to February to bring the south facing panel down to what you get with the north panels with no shade.

So, go outside on the next sunny day. Will the south roof get any sun in December? It sounds like mostly south is just fine, and the ones facing north should be ok too.

[Yogi6262]

P.S. I have a multi directional system, installed Oct 1, balancing direction and shading trying to fill the best areas. I took time lapse pictures starting a year ago to see what the shade was doing on different parts of the roof. I ended up with:

3.6 kw facing 115 at 45 tilt. (almost no shade) (1,167 kWh per kW @ no shade)
5.4 kw facing 190 at 36 tilt. (a lot of shade Nov-Jan) (1,356 kWh per kW @ no shade)
9.0 kw facing 295 at 26 tilt. (no shade at all) (974 kWh per kW @ no shade)

The last section wouldn't be as cost efficient all by itself, but with no shade, and the "base system" (electric work, permits and invertor) already paid for, adding those panels should work out in the long run.

In another 9 months I'll know for sure if the modeling worked out.