WTT is a token provided by Giga-Watt. You have to buy their tokens to host there (1 token per watt of power for the miner). You are essentially funding the build out of their facility...not exactly appealing. However, token holders get to mine at their facility for 2.8 cents kW/h, which is much better than what I get (25-31 cents per kW/h).
It's also very close to what they actually pay for electric in Douglas County, based on the last time I looked at the "industrial" scale high-end published rate for Douglas PUD (technically they'll be on a "negotiated rate" as they're bigger than 5MW, but the negotiated rates usually have large up-front infrastructure build out charges and otherwise are pretty much the same as the high end standard rate).
You're not going to find a better power rate in the US, though you can get close if you live in the "3 counties" area here even at smaller scale.