Summer School campus shutting down A/C based on ERCOT demand

So I teach summer school at a high school in the Houston area, and I currently have a small break to post this. Around 1:45 today, we were informed that ERCOT told the campus they would be losing Air Conditioning until 5pm today.

The AP in charge of summer school urged us via this email to “not move around too much” and “hang in there.” School ends at 3:45.

I didn’t realize that ERCOT had the power to tell high schools that they cannot use AC. . . I suppose it makes sense, but there are a lot of people in the building right now.

Any other government employees/schools also losing AC this afternoon due to ERCOT’s decree? Is this legal?