I have one for years - installed by BG and worked fine
then I changed to anotehr company and it stopped sending reading to the new company - but otherwise worked fine - could still take reading from the display unit
Then I changed again - and it still worked
after a few years it just stopped
just displayed an error message
So from then on I had to go outside and read the meter just like before
I am currently with EDF and I have been pestering them to get it working
Then - seemingly by magic - it started working a few months ago - they did send me an email saying it was so I plugged the display unit back in (amazingly I found it first time!!!) and it was all fine
Just as well as we are going to get solar panels installed soon and we will need one!!
As others have said - they save you money - something between £0.00 and -£1.00
why minus??
well the display unit must take some electrons - probably less than a pound a year but whatever
other than that the saving are all made by the energy company that no longer needs to send out someone to read the meter as they did before - and they don;t have to have as many telephone operators to take reading - and all that
and - on top of that they can get more accurate reading and hence know who is using what and when
But for $reasons the energy companies have 'persuaded' the government (several of them) that it should all be paid for by putting up the bills to the consumers
In the end they also have the advantage that they will open the door to variable prices based on time of day and supply
For example, at times the grid is receiving more energy than can be used - e.g. a windy night when everyone (nearly) is in bed - so energy becomes very cheap - and Octupus are even saying there can be times when the grid would pay them to take electricity and they would pay the customer to use it
WHich would be great if you wanted to charge a battery from a solar system - or an electric car!!!