> parts of a building that don't directly face the sun at all Bifacial panels (where one side faces the ground) are almost on the market for solar plants. The

> parts of a building that don't directly face the sun at all Bifacial panels (where one side faces the ground) are almost on the market for solar plants. The ground is generally light colored sand, which is great for diffuse light, so they see ~30% extra insolation for the same silicon.