Estimate the annual production hit from a shaded tree, chimney or nearby building, and see whether it's worth switching to microinverters.
A loss over 10% is usually worth pricing microinverters or power optimizers against the cost of trimming or relocating panels.
This is a simplified planning model, not a shading analysis tool — real installers use 3D site models (Aurora, Helioscope, or a Solmetric SunEye on-site) that trace the sun's path hour by hour across the whole year. The string-inverter multiplier here reflects a well-documented real-world effect: because panels on a shared string are electrically linked, even a small shaded area can drag down the output of every panel in that string, not just the shaded one.
Often yes for a single offending branch or tree, but it's a recurring cost (regrowth) versus a one-time equipment upgrade — worth comparing both against the annual kWh this tool estimates you're losing.
Yes — shading on the string's "weakest link" panel matters disproportionately with string inverters. Where possible, keep any unavoidable shade concentrated on its own separate string or use module-level electronics for that section.