The idea of having data flowing over power lines is not new.
For example, if the goal is to have regular Internet traffic to flow over the power distribution cables that reach your house, one can exploit the layered architecture of Internet. In other words, you can exploit the fact that communicating agents do not care about the physical mean that supports the information flows.
This great feature of the Internet has already proved to be extremely important when WiFi was born. You PC doesn't care about HOW information is transmitted. Routers, Modems, Access points, they hide the physical mean of communication from the user.
Therefore to use power lines in Internet communications, one only has to design appropriate modem capable of sending flows of bits on the power lines with a low error probability. This has been done, an you can find PLC modems for cheap in many stores.
What is interesting for smart grids is not the fact of having generic communication flowing over the lines. Smart grids have more specific needs. Let's give a look to them.
In Smart Grids, there are plenty of different agents that have to communicate:
- meters at users' location
- distributed generators (wind / solar / combined heat-power / ...)
- medium sized power plants
- inverters and distributed electronics
- sensing and monitoring devices
- meters have to send little amount of data (low bandwidth), without stringent requirements in terms of delays (delays are OK), and they can retransmit if their packets are lost (high packet loss rate is OK);
- switches have low bandwidth requirements, but the cannot tolerate delays (delays are BAD);
- inverters may need synchonization, and therefore they might have to transmit more data (medium bandwidth) without delays (delays are BAD).
There is a whole new world to explore in the direction of using PLC in Smart Grid Communication, and both academia and industry are very much interested in it.