Solar Shading Loss Scenario Calculator — Compare PV Shade Impacts
Test how different shading conditions can affect annual photovoltaic production and compare a light-shading, moderate-shading and severe-shading scenario.
Common solar generation basis
Shading scenarios
Scenario A · Light
Scenario B · Moderate
Scenario C · Severe
Why shading deserves scenario analysis
Shading is rarely a single fixed percentage across an entire year. A tree, building or nearby structure can affect the array differently by season and time of day. The financial impact therefore depends on when the shading occurs as well as how much array area it affects.
The scenario model
The calculator separates three ideas: the share of the array that is affected, the performance impact assumed for that affected share and the fraction of the year in which that impact is relevant.
Why string topology matters
Shade on one module does not always translate into the same site-wide loss as the same shaded percentage spread across the whole array. Electrical configuration and module-level controls can change the result.
Practical decision use
Use the three scenarios to build a reasonable planning range before spending time on a detailed site study. A small difference between light and moderate scenarios may justify further investigation, while a very large gap can identify shading as a high-value design risk.
Frequently asked questions
Does 20% shade always mean 20% production loss?
No. The relationship depends on when the shade occurs, how much irradiance is blocked and how the modules and inverter are configured.
Can shading affect power more than the physically shaded area suggests?
It can, depending on electrical configuration and the location of the shaded modules in the array.