Harry Bloomfield wrote:

Discharge lamps only achieve economy once they have been turned on for
a while. I once saw the calculations for the short period use of a
fluorescent light versus an equivalent output filament lamp - taking in
all of the factors such as wear and tear, consumption, cost of labour
replacing etc.. The filament lamp proved to be more economic upto 1
hours use.

Either the figures you looked at were grossly inaccurate, or perhaps
they were correct decades ago.


NT