I think this makes it hard to predict how much power consumption is for a certain target hash rate. At least I think that's true... check my logic please?
Kind of agree with you. I am saying that power consumption is a function of price. I never said that power consumption is a function of target hash rate. Efficiency is
defined as the relationship between hash rate and power: Efficiency (Hashes/Joule) = (Hashes per second/Watts) there is nothing more to the relationship between power consumption and target hash rate. That relationship:
(the system wide average number of hashes per second) / (the system wide average power consumption)
is the system wide efficiency (Hashes/Joule or Hashes/kWh).