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Solar & battery

Solar Panel Angle Calculator

The tilt that captures the most energy at your latitude, and what a different angle costs.

Your numbers

Result

Optimal tilt 39.0 Degrees
Loss from your tilt 2.42%
Loss from the orientation 0.99%
Combined loss 3.41%
Energy captured 96.6%
Optimal tilt here is about 39.0 degrees. At 25 degrees and 20 degrees off south you capture roughly 96.6% of the available energy.

The loss figures here are an approximation of a cosine relationship, good enough to judge whether a roof is workable. Real modelling uses hourly irradiance data. Solar is also forgiving: most roofs within 30 degrees of south and 15 degrees of optimal tilt lose only a few percent.

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Questions

About this calculator

Does my roof have to face due south?

No. Anything from southeast to southwest loses only a few percent, and east or west facing arrays still work, particularly where time-of-use rates make afternoon production more valuable.

Are tracking mounts worth it?

Rarely on a roof, and increasingly hard to justify on the ground. Panels have become cheap enough that adding more fixed ones usually beats adding moving parts that need maintenance.

The formula

optimal tilt is roughly the latitude, less 15 degrees for summer or plus 15 for winter

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