Challenging conditions, Portland edition

Portland is in the worst insolation zone in the US, Zone 6 with 3.5 hours of full sun.

Based on average high temp of 63.3F this would be

> > Average       136A/day > > > > Winter         102A/day (-25%) > > > > Spring/Fall  170A (+25%) > >

In winter all of the generated power can fit in the battery bank’s usable 110AH capacity.

Here are the figures derated by 80% for cloudy, rainy days.  This is where it gets bleak:

> > Under overcast/rainy skies (output x .20) > > > > > > Average      27.2A/day. 43.1AH deficit, 2.6 day reserve > > > > Winter        20.4A/day.  49.9AH deficit, 2.2 day reserve > > > > Spring/Fall 34.0A/day.  36AH deficit, 3.1 day reserve > >

The good news is that actual production under cloudy skies will likely be higher because overcast days are already figured into the Zone average.