It is naive to think that the government can just be 23% more efficient at getting you electricity. This excludes account for tax exceptions, cheaper financing or even government financing. The government is a monopoly and not allowing competitors in with legislation and using tax dollars to be more "efficient".
The referee should not be able to play the game.
Its naive to think that removing the rent-seeking middle-man class won't lead to savings. Same with private healthcare costs vs more socialized or single-payer systems.
"Efficient"? Nobody believes that the sourcing is more efficient. It's the profit-margin which the government doesn't need which makes the difference, they can be significantly less efficient and still beat "investors" who have shareholders to pay.