"Colin" wrote in message
...
My calculation is:

15 lights
50W per light
7p/Kw
Lights on 15 hours per day

15 hours a day seems pretty steep....................in winter you
would have to have the lights on for all the darkness hours (even
when you are asleep!)...............and during the summer you would
be using the lights in daylight!!!! I think you need to recalculate.
I doubt my kitchen lights are on for more than 2-3 hours a day in
winter and much less in summer.

Angela