solar panel shading calculator
Solar Panel Shading Calculator
Estimate the real, disproportionate power loss caused by partial shading on a solar panel.
Your Shading Loss Estimate
Why shading loss is disproportionate
Solar cells within a panel are wired in series strings, each protected by a bypass diode covering roughly a third of the panel. When any cell in a string is shaded, its current drops and the whole string is forced through its bypass diode, cutting off that entire section's power output — not just the shaded fraction. This is why a small shadow can cause a much larger loss than its area would suggest.
Practical tip
Even small, seemingly minor shading sources — a chimney shadow, a vent pipe, a satellite dish, or a growing tree branch — can disable an entire bypass section and cause outsized energy losses. Map shading throughout the day and across seasons during system design, and consider microinverters or power optimizers for sites with unavoidable partial shade.
Estimates only, based on a simplified bypass-diode model. Actual losses depend on panel design, diode configuration, and shading geometry. Consult a solar professional for detailed shade analysis.
Rate This Tool
Your feedback helps others discover great tools
Tap a star to rate: