The study states that a renationalised energy industry would cuts costs to consumers by £4.2 billion per year, and a public water sector would save £2 billion.
This equates to £160 and £75 from annual customer electricity and water bills respectively.
The study, completed alongside public service campaign group We Own It, says that state ownership would result in the savings because profits would not be paid to shareholders, and because the government could borrow money more cheaply than private sector companies.
It added that the actual savings “would likely be higher” than estimates because the costs involved in regulating the industries and outsourcing services “could be reduced”.
In addition, the study found that 68 per cent of the public want energy to be in public ownership and 71 per cent want water to be in public ownership.
The director of We Own It, Cat Hobbs, said: “Privatisation is a failed experiment while public ownership could be a much more efficient alternative.
“We could run these services ourselves and save money, either for households or for government.”
The study comes ahead of a week of privatisation anniversaries for the UK’s utilities sector. Gas was privatised 28 years ago on Monday 8 December, electricity was privatised 24 years ago on Thursday 11 December and water was privatised 25 years ago on Friday 12 December.