I also have an East-West roof and chose thin film for the western side because (1) they generally do better [than silicon] in low light or late afternoon conditions, (2) they look better, and (3) they were dirt cheap. $500US for a pallet of 50 panels. The catch is that the company is no longer in business, so it will probably cost more to dispose of them in 20 years than I paid for them now. Thin film panels contain Cadmium, and their future disposal might be a problem here or where you are.