That's half of what is going on with this material. A silver/shiny roof will reduce the amount of solar energy absorbed into the home. But it will also reduce

That's half of what is going on with this material. A silver/shiny roof will reduce the amount of solar energy absorbed into the home. But it will also reduce the heat which is radiated out of the house. So this method won't cool the house it will just insulate it better from the sun. (Which will result in cooler temperatures, though) Something (e.g. a color, surface finish) which absorbs heat efficiently also gives off heat efficiently and vice versa. That's why steel/iron motorcycle cylinders are often painted black. The amount of heat absorbed by the sun is much less than the amount of heat which can be radiated away. What these researches are trying to do is optimize this reflection/absorption ratio for the various light/infra-red frequencies. Pretty cool idea, I think.