Sales tax on electricity: This is much harder and you need to be larger-scale, but some states (like Texas) have exemptions to the 6.25% sales tax for datacenters and other companies like that. Oklahoma has a similar bill coming up.
This one in particular is interesting, I have noticed it before, I believe the exemptions is for manufacturing business and was not sure if mining could fit in that category. As far as the "larger-scale" requirement, I do not remember seeing anywhere a size / scale requirement, any more info on that or what exactly constitutes large enough to get that exemption?