Solar Access

Solar access refers to the amount of unobstructed sunlight available to a solar installation site, measured as a percentage of the total possible sunlight. A solar access rating of 90% means the site receives 90% of the sunlight it would get with zero obstructions.

Solar access is assessed during the site survey and is a key factor in determining whether a roof or ground location is suitable for solar panels. An ideal installation site has solar access of 80% or higher. Sites with lower solar access may still be viable but will produce less electricity, reducing the financial return. Solar access varies across different areas of the same roof — a south-facing section may have 95% access while a tree-shaded west section has only 60%. Installers measure solar access using shade analysis tools that account for obstructions at every angle and elevation, factoring in the sun’s path across all seasons. Some states and municipalities have solar access laws or solar easements that protect homeowners’ right to sunlight by preventing neighbors from planting trees or constructing buildings that would shade an existing solar installation.