As part of my 'to do' list re tesla s chargpoint install, I called up my energy supplier - OVO energy (who are fantastic) - this morning enquiring about off peak economy 7. All very interesting, my standard tariff is c. 13p /kWh, economy 7 reduces this to c. 6.5p/kWh (with slight increase to 15p for peak use), and whilst they need to come out and fit a new meter, this is currently free of charge and includes provision of new 'smart meter'. Smart metering sounds very neat and remotely meters the gas as well as elec, transmits regular meter readings so you dont have the hassle, and all info is displayed on a hand held unit that you have in the house, including real time £/p usage stats. Apparently the government wants to incentivise consumers to upgrade to smart meter technology, so is free for the moment (but not widely publicised). Smart meter cost of provision will be shared out across all energy suppliers by way of a flat rate tariff increase (ie. everyone is already paying for it) - however it's up to the individual energy suppliers how and when they implement, and also what tech they use.