Washington (WA)
How shading impacts your solar system performance in Washington
Even small amounts of shading can disproportionately reduce solar output. A shadow covering just one cell in a string can reduce the output of the entire string. New tree growth, nearby construction, or seasonal changes in sun angle can all introduce shading that didn't exist when your system was installed.
How Washington's climate affects this issue
Climate
temperate
Sun hours
3.4 hrs/day
Soiling risk
low
Solar adoption
moderate
Related issues
Partial shading
New tree growth, nearby construction, or seasonal shading patterns reducing output on part of the array.
Typical loss: 5–30%
Self-check tip:
Check panels at different times of day. New tree growth or structures may cast shadows that didn't exist when the system was installed.
Check your Washington solar system
Use our free Solar Loss Checker to estimate how much energy your system in Washington may be losing.
Check my systemBased on conservative solar performance modelling and published degradation data
Updated April 2026 · Structured performance modelling
How we calculate →