Installation

Shade Analysis

Shade analysis is the process of evaluating how much sunlight a proposed solar installation site receives throughout the year by mapping all obstructions — trees, buildings, chimneys, power lines, terrain features — that cast shadows on the panel area at different times of day and seasons. It is a mandatory step in professional solar system design.

Even small amounts of shade can have outsized effects on solar production. In a string inverter system, shade on a single panel can reduce the entire string's output by 30-50% because all panels in series share the same current. Shade on just 10% of a panel's surface can reduce that panel's output by 50% or more as bypass diodes activate and remove entire cell groups from the circuit.

Professional shade analysis methods include the Solar Pathfinder (dome-based skyline mapping), Solmetric SunEye (digital fish-eye camera with software analysis), satellite-based modeling through platforms like Aurora Solar and Helioscope, drone-based LiDAR scanning for precise 3D obstruction mapping, and smartphone LiDAR apps for preliminary assessment.

The output of a shade analysis is typically an annual shade loss percentage — for example, a site might have 5% annual shade loss on the south roof face and 15% on the west face. This data drives key design decisions: which roof faces to use, whether microinverters or optimizers are worth the investment, how many panels are needed to meet production targets after shade losses, and whether trees should be trimmed.

Shade analysis also accounts for future growth. A tree that currently clears the roofline by 10 feet might grow into the shade zone within 5-10 years. Good shade analysis considers both current and projected future obstruction profiles to prevent production decline as vegetation matures.

Frequently Asked Questions

How much shade is too much for solar?

There is no hard cutoff, but sites with more than 20-25% annual shade loss are challenging to make economically viable with string inverters. Microinverters and power optimizers improve returns in shaded conditions by isolating panel-level losses. If shade exceeds 40-50%, the production loss may make the investment impractical regardless of inverter technology.

Should I cut trees for solar?

It depends on the tree's value, the shade impact, and your priorities. A tree shading 2-3 panels for a few morning hours has minimal impact. A large tree shading half your array during peak sun hours significantly reduces returns. Some homeowners trim rather than remove — raising the canopy while preserving the tree. Always check local tree ordinances before cutting.