I recently got a gizmo installed at home that samples my electricity usage once every 10 seconds. I've become a little transfixed watching the graph update as various appliances in my home turn on and off.
For instance, turning on lights results in a small and simple bump up a couple of hundred watts. Turning on the microwave a huge 1.2KW jump. The washing machine usage moves up and down depending on where it is in the cycle.
I started wondering whether there'd be some ways to automatically work out what devices are running by what you might call their 'power signature'.
Essentially what I want is an algorithm that watches what is effectively a 0.1Hz signal representing usage in watts, and can say 'Looks like your washing machine was on between 09:00 and 11:00 today.)
The complication of course is that multiple appliances can be running. As a human you can sometimes resolve that (E.g. This shape looks like the washing machine was on, but someone also turned on the microwave in the middle).