Unfortunately, this is not the first time I have heard of this ridiculous rationale for a rate hike. It's like, OK folks, you did a great job of cutting your electricity consumption like we asked you to, so now we have to penalize you for doing that (because we need the same revenue stream as we always have had)!"
The utility industry's business model is archaic. Ever since the first light bulb was sold, electricity consumption has increased, until nowadays. Just what the electric "business" wanted it to until today. Since utility stocks are considered very safe and permanent investments; especially for "widows and orphans," they need to produce constant dividend revenue for eternity. Well, today, they are not, and THIS is the real reason for the rate hike. The weather factor is a convenient scapegoat.
It is not capitalism at work, it the accountants at work. It's the same as Amazon seeing the unit sales of the Echo declining, so to make those darn sales goals as last time, they raise the product's price to at least keep revenue the same (at least they hope it does.) If companies lowered the price, they likely would sell more units and get sales revenue up, but companies are loath to lower their prices, ever. It was done in the industry I worked in for many years, too. I hated it. It is done in most all industries. As long as there are Managerial Accountants, this practice will continue.
Another fun example to leave you with: When a drug becomes generic, the drug companies have to recover that revenue, so the price of all their drugs go up.
Nevertheless, I would be writing to the utility commission and elected officials about this. Those folks are reaching into the back pockets of the utility companies in many ways (e.g. political contributions, for one.)