When the difficulty hits 50B at current tech & current avg watts, big players will start thinking about calling a world-wide truce. Hashrate will top out somewhere after 400PH and well before 700PH unless someone invents a quantum miner.....
Next gen ASIC is claimed to be 0.2w/GHs (SP). 700PH is entirely possible. To to mention i know some mega miners are expanding with 3 cents per KWh contract. They will keep expanding to get a bigger pie. Only idiots like OP keep using "bitcoin calculator" with wrong variable.