Much of the focus of these discussion groups appears to be related to ‘online’ energy monitoring. I had an application to build a comprehensive picture of half-hourly electricity demand over multiple properties, where the difficulty of reliably receiving online data from around the meter (and a micro-cogeneration unit) suggested an ‘offline’ solution. I used three different techniques to record half-hourly consumption using an Arduino with a RTC and SD Card shield and the Emon shield for CT/VT recording, and also two alternative pulse recording techniques. Key to the application was ensuring that the loggers were correctly set-up and that they showed their operation status during installation – nothing more disappointing than discovering a missing SD card a year later! Some loggers have operated for years with only occasional data retrieval by swapping the SD card and have survived multiple power outages with good correlation to Utility meter data.
I’ve provided a page on my website to describe these robust Arduino applications and all the sketches can be downloaded from the site. At some stage I’ll add more about analysis techniques, but you can see part of the analysis on this webpage.