It's a compelling idea but it really won't work. I knew the Sid of the British Gas "tell Sid" adverts because I worked at the place where all the crap privatisation ideas originated. The problem being faced then by all the utilities was 40 years of chronic under-investment by governments of all colours combined with blinkered and utterly shite management. Selling them off was Mrs Thatcher's own blinkered way of passing the capital expenditure parcel.
Governments are rubbish at running things that require long term planning because politics is all short term.
Energy was cheap because energy WAS cheap. Dad bought 4 gallons and got change from a pound. But the appalling mis-management of British Leyland by Lord Stokes crashed the motor industry, and as for British Rail's multiple-unit slam door rolling stock words fail me.
So we've been stuck with a vast backlog of maintenance and replacement at colossal expense. But HMG has been total inept as a regulator which says it would be crap as an owner again.
To buy-back the utilities is now unaffordable. To nationalise without compensation would be to follow the example of Hugo Chavez and other rather less wholesome leaders, would crash the capital markets totally and probably finish the Euro. Begins to sound appealing.