Tl;DR: installing a heat pump could cut a huge chunk off your electricity bill.

I have an open-floorplan vaulted dining/living/kitchen room that, because of it's huge windows and vaulted ceiling, required us to run the AC til it was freezing in the downstairs just to keep that room comfortable.

I just installed a super efficient mini split heat pump and it is wayyy more comfortable and our electricity consumption has gone way down. The new breed of mini splits are way more efficient (23+ SEER2) than your typical central AC (11ish SEER2). SEER2 is the technical term for measuring cooling efficiency, but that basically means cooling with one takes less than half as much electricity as your central AC would. That's on top of the benefit of only cooling the room that needs it (instead of freezing out the downstairs to get the room you care about cold enough)

And the cool thing is, they can heat your house in the wintertime too. And they are >300% efficient. meaning for every unit of energy you put into it, it gives you 3-5 units of heating, because it is not heating the room, it is just transfering heat from the outside.

There is a federal tax rebate of 30% on your taxes and a rocky mountain power rebate of $600 to install them. I personally DIY installed mine so I missed out on the Rocky Mountain power rebate, but all-in it was ~ $900 pre tax rebate.

If you're a DIYer, the install is pretty straightforward, DM me with questions. Otherwise, if you're going to have a pro do it, look for Mitsubishi, Daikin Fujitsu, or Gree, those are the most reliable brands.