Thunder Bolt
Silly old bat
The lounge lights are halogen. Each bulb is currently 42w, so that's 252w when on. I really don't understand how these numbers translate to money.
The rest of the house has LED lights inset into ceilings pretty much throughout. The box of bulbs for those suggests they are low energy, the little picture seems to suggest they draw 4.5w each and put out 50w/345 lumens. Does that sound right?
1 unit of electricity - I kilowatt - 1 hour.
4.5 watts would take 22.22 hours to burn one unit of electricity.