Should I choose monocrystalline, thin film or polycrystalline solar panels ?

Between monocrystalline and polycrystalline there isn’t a lot of difference except that a polycrystalline panel is slightly larger than the equivalent wattage in monocrystalline. Thin film panels are larger again and the extra space can take up valuable rooftop real estate in terms of adding extra panels at a later date.