It looks like you are trying to go with index power rate? you gotta be real careful with that, if prices spike and you don't manage the miners in time (can happen overnight), your energy bill will basically ruin a years worth of profitability
I wanted to go with the day-ahead index, where I always know what the rate will be in 24h and it's not subject to instant spikes like the real-time LMP. I'm not worried about the spikes because I will write custom, automated software to cut off the Internet to the ASICs to power them down. Maybe other farms will want the software.
This day-ahead index is a specific agreement with the energy supplier, not oncor, right?