Winter Sun Calculator
Plan for winter solar production—the make-or-break season for off-grid systems.
Your Location
Average in June/July
Winter Expectations
Winter Sun Hours (Dec/Jan)
4.2 hrs/day
vs 6 hrs in summer
Production Reduction
-31%
Compared to summer output
Recommended Oversize
+45%
Extra panels to cover winter
Winter Strategy
- • Add 45% more panels than calculator suggests
- • Consider a backup generator
- • Tilt panels steeper in winter (55°)
- • Keep snow cleared from panels
Pro Tip: At latitude 39.5°, optimal winter panel tilt is about 55° from horizontal. This captures more of the low winter sun. Many off-gridders use adjustable mounts to optimize seasonally.