@kabuku I'm city center and have largish roofs (large enough), but if you go big, the material cost scales with it, and if you go small, the savings isn't there. It's a luxury… There's no practical benefit with reliable power.
@mandy maybe third world countries will buy them to strip metals and separate the materials like with other electronic trash. -_- Or the poor can use them if they just have 50% reduced efficiency etc.