For multiple reasons (curiosity, interesting data, student data project, etc), I've built and installed a power usage system in my house. The system is completely home-built and may not be completely accurate, but it's a fun project. Below you'll find the last entries from my in-home logging system (for debugging) and a plot of recent data.
05,18,30,1704,1907 06,03,2016,05,18,31,1726,1897 06,03,2016,05,18,33,1711,1910 06,03,2016,05,18,34,1648,1900