This is also relevant to large-scale installations. For a single family home, perhaps you don't care if you use 30% of the roof area or 32.5%; but if you're bui

This is also relevant to large-scale installations. For a single family home, perhaps you don't care if you use 30% of the roof area or 32.5%; but if you're building a solar farm for a whole city, then those extra 2.5% are a good number of Km^2 which you can save; or have as extra safety-margin production capacity.