Most specs for light bulbs list luminous efficiency (or, more accurately sometimes, luminous efficacy) but not energy efficiency. Luminous efficacy tells you how bright the light is as observed by a human eye per unit of input electricity. Unfortunately, the human eye is terrible at measuring power and its very hard to convert between lumens/spectrum/human eye/radiant power.
I'm curious as to which types of lights have the highest energy efficiency, which I'm defining the amount of energy that would be absorbed by a perfect absorber surrounding the light bulb divided by the electric input. In this metric, the light is just a one form that the energy takes between electricity and its absorbed form (eg, heat). Obviously the exergy is degraded in this process, but I'm not worried about that here.
I would expect that incandescents are near 100% efficient by this metric since the only losses should be conduction/convection from the element through the near-vacuum and wires. This weakly scientific analysis suggests that LEDs are probably only 40% efficient by this metric because all their luminous inefficiencies are thermal losses in the cells. I think fluorescent lights might be extremely efficient by this metric but I can't really find any data.
I found the phrase "radiant efficiency" somewhat useful but still can't find much in manufacturers data sheets. Is there a better name for the metric I've described or a good database for what values might be?
In response to comments: I am interested in the power radiated away from the light bulb in the form of electromagnetic radiation divided by the electric power that goes in to the lightbulb. I don't care about the wavelength of the light (even though I understand that it changes both how much you can see and how much can be recaptured in another form later). I do care about thermal losses inside the bulb that don't radiate power across a distance.