Bare faced bullshit!
This "DECC's figures reckon that not deploying smart meters in every UK home (by 2019) will cost consumers £6.3bn over 18 years" is, by the admission of the power companies, total and utter bullshit. How these arseholes can keep a straight face peddling this shit is beyond me.
These lying, thieving, scum have already stated that domestic electricity bills *must* go up and must go up by *a lot* in order to pay for infrastructure and the coming energy shortfall in the UK. What this is about is paying twice as much for half as much electricity.
Think I'm making this up or exaggerating? Read a few El Reg articles from the past couple of years on Energy supply and demand, rolling brownouts and the need for infrastructure upgrade.
Edit: Can't find the El Reg articles but this gives the gist http://www.uswitch.com/gas-electricity/news/2012/08/20/power-cuts-in-the-uk-110bn-of-infrastructure-upgrades-needed/