The energy saving depends on whether you're heating, cooling, or doing
The waste heat of incandescent lighting is not wasted if you are heating
the room anyway. If you're running the A/C, then that heat is doubly
wasted, as you then have to pay to get rid of it.
With open windows, or outdoor applications, the difference in what you use
is what you save.
In a message dated 3/9/2011 7:23:15 P.M. Eastern Standard Time,
Lighting in a typical house is pretty low load. Replacing an old frig,
pool pump or TV will probably save more than all the CFLs.
However, in my home office with four 75 watt incads in a ceiling
fan/light, changing to CFLs dropped the room temperature 3-5 degrees in summer.
RFI mailing list