How roof capacity is estimated
Field practice allows 60–70 ft² per kW on traditional flat-roof mounting — that covers the panels themselves, tilt spacing so rows don't shade each other, and walkways for cleaning. We recommend at 65 ft²/kW and round down to a practical half-kilowatt.
Count only true shade-free area
Water tanks, parapet walls, neighbouring buildings and trees all cast moving shadows. Watch your roof at 10am, noon and 3pm — only area clear at all three counts. Partial shade on one panel can pull down its entire string.
How many kW of solar fits on my roof?
Plan 60–70 ft² (5.6–6.5 m²) of shade-free roof per kW, including maintenance walkways. A 450 ft² roof fits roughly 6.5–7.5 kW.
Does shading matter that much?
Yes — a shadow on part of a string can drag down the whole string's output. Only count area that stays shade-free through the middle of the day.
My roof is small — what are my options?
High-efficiency panels (22%+) deliver more watts per square foot, and elevated structures can reclaim area above water tanks — at extra mounting cost.