Any big mining operations in the U.S. using real-time or day-ahead electricity pricing?

Hey, I'm curious if there are any commercial ASIC mining farms in the U.S., particularly in Texas, that have worked out real-time (hourly) or day-ahead pricing with their power companies. Also wondering if there are any farms still running older ASICs like the Antminer S9 or Avalon 1146, which usually aren't profitable. I'm looking to create some software that can use real-time or next-day grid prices (ideally ERCOT) to remotely control less efficient ASIC miners based on power costs. My goal is to see if these older miners can actually turn a profit if they operate overnight or when electricity is cheaper. I've run some initial numbers. For a medium farm using at least 100 kW, it seems you could achieve a 200-day ROI on a used $350 Antminer S9 if power costs stay below 4¢/kWh (with about 60-70% uptime). The plan would be to shut it down during peak hours, like afternoons or evenings, especially in the summer. This takes into account the higher demand charges for a 60-70% load factor instead of keeping it running 24/7. The demand charge is about 2¢, and the energy charge is around 2¢ during that runtime period. You'd likely need to connect a small Raspberry Pi to the same network as the miners, and my backend would send out commands to manage the switching. Sure, the miners aren’t as efficient, but heat isn’t a big issue since it’s usually cooler when electricity prices drop. Is there anyone out there with these older ASICs who might be interested in this kind of service instead of just tossing them? If not, I might just start my own setup with a few dozen used ones.

Update: I talked to an energy provider. They told me that it's possible to get real-time marginal energy prices in Texas on ERCOT if the load is at least 50 kW. That requires only 15 Antminer S19 units or 50 Antminer L3+ units or 300-350 RTX 3060 video cards. I'll be opening up my mini warehouse in May/June with an index power contract. Looks like the total power cost (energy + dist. + premium) + tax will be 7.8¢ for 100% uptime, or 7.1¢ for 95% uptime (where the machines are powered down during peak load hours). It is possible to buy older ASICs like the Avalon 821 and run them profitably overnight, when the rate is just 4.0¢. Uptime would be 60%. If the payback period on them is < 300 days, it might be worthwhile.

Update: I realized it would be a bad idea to buy very old ASICs, because not only will they break, but because the cost of building that capacity is too high. It makes no sense to buy an Antminer S9 for $280 if the buildout cost (electric + ventilation) is $200/kW. The newest gen is also a bad idea, because it's harder to insure and I risk more capital per terahash. The T17 or S17 seem to be better choices. They have reasonable efficiency while I can still take advantage of changes in the energy index. I wrote code to analyze ERCOT rates for the past 30 days. For the T17, the all-in rate would be 6.72¢ with 100% uptime, or 6.08¢ with 95% uptime. That comes out to 3-6% more profit on average by powering down during peak prices. Once I can get rid of the pesky sales tax and buy transformers instead of using ONCOR's secondary service, the rates would be 5.7¢ for 100% uptime, or 5.13¢ for 95% uptime. Of course, these rates would be 1-1.5¢ higher during the summer. There is no way to avoid that.