What eats all the electrons -- or -- understanding household power consumption
What I did was contact my electricity supply and said "send me one of those energy monitor thingies free pronto"

Some months later it arrived.

I clipped the wireless current sensor around the main line/hot between meter and main-panel (consumer unit), inserted some batteries into the wireless transmitter and I was then able to see on the receiver/display unit how the power changed as I turned various things on and off.




This particular unit display current usage and lets you look at averages for prior days/weeks/months but if you actually want to spend your own hard-earned money, you can buy energy monitors you can plug into a PC and do data logging, graphing etc.