Well, really there are only two, capturing more sunlight, or capturing sunlight more efficiently. Since we need sunlight for other things as well it's better if

Well, really there are only two, capturing more sunlight, or capturing sunlight more efficiently. Since we need sunlight for other things as well it's better if we don't waste it, but right now that doesn't really seem to be a limiting factor (there are still plenty of roofs without solar panels).