Spaceships pushed by LIGHT – the future of space travel?

90% efficiency for solar sail sounds to high. From the incoming solar radiation just a small fraction seems to be converted in to motion and maybe 10% as heat (not a perfect reflector) But most of that light is reflected so is most of the energy.
While a solar photo voltaic cell has a 15 to 40% efficiency in converting light in to electricity but since it absorbs more than that the rest is converted in to heat and very little gets reflected back.
Not sure what 90% efficiency refers to when talking about solar sail but I will have no problem keeping a 1 square meter plastic mirror in the sunlight it will not push me in any meaningful way while a 1 square meter PV even with 16% efficiency will produce around 160W if facing the sun directly as seen from earth and that 160W is about the same power a normal person can put out for a reasonable amount of time so significantly more than a solar sail can do. I think that 90% efficiency therm is misleading for solar sails hope someone can clarify this (a power number for 1 square meter solar sail receiving energy from the sun here on earth)