[Svartalfiar]

Better to put them at ground level, easier to maintain, doesn't screw up your roof, etc

Which then takes up quite a lot of valuable square footage, that needs to be placed decently far from trees or anything that'll shade 'em.

[palmer]

All houses should have shade trees shading them. Mine are elm and pecan. Also I have plenty of spare square footage in the yard to use for panels