If you want to built a smart energy meter by yourself to understand this you start from beginning. take an energy meter(electronic), take two wire from the the cal. led and pass it through an opto coupler and use that as a counter signal any microcontroller(let AT89S52), AND FOR EVERY 10 BLINK COUNT THE SIGNAL as 1kW and send the signal to a gprs module(sim900), now you push the signal to a website in every 5min, the data collected in the website can be analyse easily. for the back end of website you can use java, python,php etc. ther you can get a good idea how the smart meter work