Every energy supplier has a different smart meter. They are not compatible. British Gas came and installed smart meter in our house. Six months later we changed our gas supplier and the smart meter no longer works as a smart meter.
Personally, unless you are a monumentally disorganised and energy wasteful person their advantages are over hyped. The main things that save energy are good insulation and good housekeeping: having thermally lined curtains, drawing them when the lights go on, not having the heating on longer than necessary, keeping the thermostat as low as comfortable, thermostatically controlled radiator valves, low energy light bulbs etc etc. These are the things that really save money, not rushing round the house turning (low energy bulb) lights off all the time..