Re: estimated net "benefit" of £5.7bn by 2020
Phone them up, demand a credit on your next bill, and to reduce the estimate because it's obviously wrong. Them accurately billing has nothing to do with smart meters.
If anything, it's so they can detect unmetered usage. That costs them a lot, and it's still possible by just cutting a wire to tap into anything you like, electricity-wise. Illegal, yes, but still possible. With smart meters, if their numbers on your line don't tally 24 hours a day, they know there's something up and they could even send data down the lines to see if you're pulling from somewhere you shouldn't be.
And smart meters aren't currently accurately billing anyway (a lot are locked into the original supplier and can't move suppliers, which means they don't read at all any more and many of the so-called smart meters are just current-reading clamps, not actual meters), plus the savings on one visit a year that would be required to keep your estimate accurate just aren't enough to justify an always-on data connection.
Smart meters are there to provide even more complex billing systems which you can then practically "verify" if you can be bothered, but they can also just charge you 2.5% extra between 4.14 and 5.47am at any point they want, write it in the T&Cs, update your billing algorithm and blam, you're gonna pay it. Whereas at the moment they **were** until very recently being forced to simplify billing and get you off those kinds of plans onto a flat rate (that "simpler bills" plan is now dead in the water, by the way). This way they can charge a fortune for the expensive peak usage in the future just with a software update, that's accurate to the second, not to the once-a-year-visit.
Smart meters aren't there to help you. They are there to change the terms and conditions in the future. Software updateable on an always-on device, there's a reason for that. And then they can start introducing the devices that contain the REAL reason - which is to start cutting you off in peak periods and separating out the circuits into "necessary (1A max)" and "optional and we can cut it off (the rest of your 100A)".
Because that saves a BUCKET load of money as you can just turn off peak demand, basically, and then blame the customer. Oh, and you'll have a "Premium" account available that doesn't cut you off but costs 10 times as much. Again, software-updateable. And - probably the biggest reason for them wanting actual CONTROL of your usage? So they can cut you off the second you don't pay without needing to send anyone around. They can literally just kill the circuit remotely and, if it doesn't get negotiation over the line with your smart meter, assume that it shouldn't be supplying power. Then you can't even bypass the meter.
Today - "energy meter", a £20 device from Maplin's.
Tomorrow - "per-second accuracy billing meter", to introduce a myriad of complex tariffs for users that they can't do with conventional meters (remember Economy 7 which has TWO numbers on the meter, etc.? This can provide accurate power usage information down to the second for the entire customer history).
The day after - an in-circuit upgrade "to provide a better service".
The day after that - cut you off when the football is on because everyone else has a cup of tea and they don't have enough nuclear running any more to cope with it. By the way, you're still paying for everything you do use.
The day after that - you don't like the above and want to move companies? No problem. Click. You're without power.