Mathematics question: estimation of shadow around buildings

[Gunnar Wegner]

Hello group,

let's say I want to locate PV panels on the ground, next to a building. The
roof is not an option. Putting the modules south of the building is also
not possible.

Is there a quick way to estimate the distance I'll have to keep to the
building (given its three dimensions and position on the globe) in order to
prevent my modules from being shaded throughout the year? Has anybody
modelled this kind of problem in a CAD or GIS software?

Thank you,

Gunnar
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