In general flourescent
lamps use power in the following %
37% heat radiated
20% heat in discharge
18% heat at electrodes
25% usable energy for conversion to UV
This is based on a 32 W T8 lamp.
This is based on a visible light lamp, probably what is in your ceiling right now. I do not have the energy diagrams for a tanning lamp. Since all Flourescent
lamps are 254nm radiators it would stand to reason that it would be more efficent to closer 254 you get. However, for the lamp given these are real numbers. I do not have the spectral nm for the heat. I can send the diagram to any who want it.