The bigger operations already are using so called green energy. There are large operations in the north west where hydro is abundant and cheap.
This might be a few years off but I am considering setting up a farm where I am. We are planning on a very large solar installation at some point in the near future and we will probably have way more supply than we can use. I wouldn't mine btc but running some other algo hardware and throwing it at nicehash or other smart pools would probably be a good use of that power assuming I can get the hardware cheap enough.
No one with any working braincells is running larger than at home operations on standard power costs in most of the country. My state has some of the lowest cost power in the US and it's still not profitable to mine most coins and it doesn't get much better with commercial rates. I'd also bet that the larger AI farms will also do what they can to run on solar, wind, etc so that they pay as little as possible for power.