It is a couple of decades now since electricity cables were first demonstrated as potential telecomms networks, and some applications of that are commercially available now. You can even use special adapters that plug into a mains socket to communicate with devices in other sockets, though wireless LANs make that much less significant now.
However, an obvious derivative of that has also been known for decades but is still missing. That idea is to packetise the electricity itself. The electric current would still be constant, but each bit would have a communications packet written on it. That would allow electricity to be sold peer to peer, to be assigned to specific purposes, and rationed in time of shortage. It is closely related to smart metering, just a different way of doing something similar.
Here’s an example of how this may be used in practice: A power supplier could issue packets of electricity labelled according to their permitted use. Most of the time, all packets would be labelled open use and could be used for any purpose. When load is high and supply is limited, some packets would be marked restricted use. They could be used for lighting or a hair dryer, but not to power a freezer or electric heater, or battery chargers. Enough open packets would be issued to provide minimal power to these secondary uses, so that your ice cream doesn’t melt and your gran doesn’t freeze to death, but they would provide an excellent way of smart targeting for power rationing. In fact, grans might be allowed to use power for heating when some other homes aren’t, if they are known to have alternative supply for example.
What is meant by ‘each bit’ needs some thought though. To offer useful service potential, energy needs to be broken into quite small pieces. An electrical unit is far too large. I think a Joule is about right – 1 Watt for 1 second but I haven’t really though about it much. Millijoules would be feasible technically, but I don’t think they add much in terms of potential.
Energy from different suppliers could be labelled differently, but share the same wires, just like telecomms traffic. You could choose to run your house on just renewable energy, or just nuclear, or be bloody minded and insist that it has to come from a coal station just to annoy your green neighbour.
There has to be an incentive to use compliant appliances, and they would cost a little more for the embedded intelligence to understand the packets. The main incentive would be price reduction for the energy used, or perhaps event-specific rewards for allowing a local ban during peak times. They could even be offered in advance.
Peer to peer sale of electricity from a small wind turbine or from solar panels on a roof would work too. Instead of selling electricity back onto the grid at a poor price and some neighbour buying it back from the grid at a high price, peer to peer allows direct sales at mutual advantageous pricing, cutting out the middle-man and adding competition.
So there could be a market and it could work. I guess it’s up to the industry to decide whether this is a sensible alternative to smart meters.