On Thu, 18 Jan 2018 14:41:25 +0000, Chris Green wrote:

Johnny B Good wrote:
Twenty years ago, it made good financial sense to invest 50 quid in
CFLs
to knock 250 quid off the annual electricity bill.

That means you were consuming something like 250 watts of lighting for
24hours/day for the whole year, seems unlikely to me.

My 'rule of thumb' for electricity costs is that 1 watt continuously for
1 year costs around £1. (8760 hours in a year, so 1 watt is 8760
watt/hours, 8.76kwH at 12p/unit costs £1.05) It's probably a bit more
now as electricity costs a bit more but even then your figures seem a
bit high unless you have a very big house.

I have a very big house.

--
Johnny B Good