Energy meter

Convert your old energy meter to a smart meter

Keeping track of your energy consumption with a classical electric energy meter (ferraris meter) is a tedious task. You need to got o the location of your meter and read it regularly and then enter the recording data into a software to analyze it.

There are off the shelf solutions to the problem which add an optical sensor to the meter and then let you analyze the results remotely with another device.

With a smartphone or IP camera you can easily get access to your meter data remotely from your computer:

1. Place the IP camera or a smartphone with an IP camera app in front of your old meter
   • you'll now be able to take snapshot images of your camera
2. run a script that takes a picture of the camera every second
   • then compares the previous picture with the current
   • if the difference between the pictures is above a treshold there has been a turn of the ferraris meter
   • taking the picture is done with curl
   • comparing the picture can be done with imageMagick
3. each turn is 1/75 of a an kilowatthour - 48000 J
   • for each turn save a picture and add the current timestamp and watt rating 48000 J / number of seconds for the turn e.g. 10 secs=4800 Watt, 20secs=2400 Watt ...
   • again imagemagick can be used for the purpose
4. if you like you can convert the results to a video

http://www.bitplan.com/download/zaehler2012-12-07.mp4

1. if you like you can convert the results to an Excel sheet to display

If interested in the script and more details or if you have further input please contact me via wf (a-t) bitplan.com

english links

• http://www.readyourmeter.org/

german links

• Volkszähler
• Wikipedia Artikel zum Ferraris Zähler
• Gira Stromzähler Sensor
• ELV Funk-Sensor Wechselstromähler
• http://www.mikrocontroller.net/topic/205942
• http://hobbyelektronik.org/w/index.php/Energieerfassung#Stromz.C3.A4hler

scientific articles on the topic

http://labplan.ufsc.br/congressos/powertech/papers/256.pdf