tripling the heating/cooling power isn't "needless complexity". Full solar heating pretty much works if either you have some truly massive roof area or live in

tripling the heating/cooling power isn't "needless complexity". Full solar heating pretty much works if either you have some truly massive roof area or live in place with no winters. Here solar power is at most 1/4 of summer one, at time where you need it most. Remember, even with free panels, roof space is limited.