The "Correct" price for electricity is one price to be connected to the grid and several more relating to one's power used, power factor, peak demand, and the like.
The average price paid is lower than the "correct" price, because charging the "correct" price adds lots of measuring and billing costs. It's better to allow some subsidizing to be happening than to spend more just to make sure it isn't.
An easy way to do it would be to charge the "correct" marginal cost for all kWh and have a separate fixed fee. My water bill is something like $50 fixed and then a small amount for the water I use after it; the electric bill could work the same. Ronald Coase argued that here
Commercial meters have priced kW for a long time and I think the reason residential didn't was more along the lines of they're more homogeneous than the meter costs. But either way, it seems everyone is getting smart meters now and you could match it up to theory exactly if it were politically feasible.
Example nicked from this online Berkeley lecture.
Monopolies are bad (morality and economics agree here).
Firms that pollute are bad (morality and economics agree here).
What about monopolies that pollute?
What about strong monopolies that pollute and receive government subsidies?
Well...
Pollution, and other negative externalities, cause firms to produce too much of their product. That's because they don't pay the full cost of the product, including the impact of pollution.
The equilibrium behaviour for monopolies is to produce too little of their product, to keep prices and profits high.
So a monopoly that pollutes is subject to two opposite tendencies: the unpriced-pollution tendency to produce too much, and the monopolistic tendency to produce too little. If the effects are of comparable magnitude, then the monopoly might be much closer to social optimum than a free market would be (the social optimum, incidentally, will generally involve some pollution: we need to accept some pollution in the production of fertiliser, for instance, in order to have enough food to stop people starving).
In fact, if the monopolistic effect is too strong, then the firm may under-produce, even taken the pollution effect into account. In that case, we can approach closer to the social optimum by... subsidising the polluting monopoly to produce more!!
And that, my friends, is why economics is not a morality tale.