Basically smoking hopium is full of shit as 5.5 cents power cost is a solid money maker for the t21
Another approach would be buying only 2 T21s, and using the rest of money ($3625 at the time of his post), for two T21s his daily bill would be $17.6 which means he has enough to pay 205 days without having to cash out BTC, this approach works as a hedge against price drops, because if the price of BTC drops and he has no side cash to pay the power bill, it would mean that in some months/weeks he may be forced to sell his entire BTC earnings to cover the power bill.
Obviously, you could say, why not buy only 1 miner and use the rest of the money for power, that would also be valid, the above is just to explain the idea of hedging your investment to account for power bills paid during times when BTC is doing terribly.