Kinda odd the scientists used "watts" to measure the light output
Well light is energy (Joules) in its own right and the rate at which energy is produced or consumed is power (Joules / second = Watts).
Produces 69 picowatts of light....Not much you can do with that
Yeah, you'll need a shed load of the things to be able to read the newspaper, let alone keep the drinks cold.....