I currently work in the solar industry as an installer of P.V.(photovoltaic), S.D.H.W.(solar domestic hot water) and radiant systems. One of the first things we learn is that a well designed passive solar house is the best (simplest) method of heating the living space from the sun.
Stated simply our house will have large southerly facing windows with a calculated overhanging eve to allow winter sun in to warm the floor & cob walls. The angle of the high summer sun will be blocked by the larger eves and trellises planted with perennial vines.
We plan to use active solar technologies but that will come in due time.