Here’s a clever way to monitor your electricity usage. Connect your webcam to this this £5 software app and it will “read” your meter and show your power usage complete with fancy graphs…
If your electricity meter is like the one shown here you will notice that in the middle of the meter there is a rotating disk which you see edge on. This disk rotates faster or slower according to how much electricity is being used, and by counting the number of revolutions of the disk you can accurately determine the rate of electicity you are using in your home.
Calc-Electric is a piece of software for your pc which measures the rotation of this disk using a standard pc webcam. You’ll notice that the edge of this disk has a dark mark on it, often in black or red, and this is what the Calc-Electric software is looking for.
Within the software the rotations are stored and various screens show you the rate you are using the electicity, how much it is costing, and how your usage has varied over long periods of time. You can record the data for days if necessary, view it as graphs, and export the data to excel to do your own study of it.”
Looks like I’m 5 years too late! I just tried webcam-reading-meter out of interest and got it mostly working, updating a logging web service too:
http://firtl.com/2013/04/25/read-gas-water-electricity-meter-with-webcam/
I ‘read’ the numbers on the dials. My source is all there, it’s a bit nasty in places but should be enough to give someone else a head start.