I guess the notion is that it does not actually consume resource (yeah I know it does, but not in the same way) like water, gas and electricity. That is once your FTTP network is built there is a small (and it would be small) electricity cost to run it with some maintenance but generally the costs are rather low and somewhat fixed.
However don't get me wrong it was a crackpot idea. Though if you listened in the past by now electricity is supposed to be too cheap to meter 
He, selected BB because 1, he was after the youth vote, 2, the utility companies are non British owned so off limits to ever being state owned via force like he planed to seize BT's assets
Strange comment.
Not sure that utility companies not being British owned makes any difference.
Do foreign owned companies not fall under British law anymore?
Are their shares somehow different?
It was a ridiculous idea to offer free broadband and to want to nationalise OpenReach.
He intended on nationalising the National Grid and water companies too.
There's nothing to stop a government nationalising something because it's foreign owned.
National Grid PLC is hardly owned by British investors.