I have yet to see anybody publish radiometry readings on those compact bulbs so I don't know how well they rate.
Solar radiation produces way more heat than the actual temps. Ever get a sunburn? Notice how much heat was created and is now being dissipated through that very red skin? That energy has nothing to do with temperature, skiers can get those sunburns in below-freezing temps. UVB is not at all hot, no raise in the ambient temperature in the cage, but it raises the core body temperature of reptiles quite nicely.
Beardies are set up to store up sunburn-type energy in their bony armor plating and generate that kind of heat all the time. Without UVB, they just plain can't do it though and they don't tend to get enough heat in their bone marrow. Immune system problems are often seen in beardies without access to good quality ultraviolet light and there's no supplements for that.
The Zombie Mama is here!