I have one of the older versions of TED. It sends it's monitoring on the home's wiring. But only on one circuit of the home's wiring. Newer ones use wireless communications.

With the TED and multiple transformers and transmitters you can actually monitor kwh's used over time for both you and your neighbor.

The software can even be taught monitor specific appliance usage based on recognizing the demand each creates when switching on and off. No need to put transformers on everything. Though it takes a computer on 24/7 to keep track at that level.