Quote from: amaclin on October 01, 2014, 12:35:37 PM

Quote

ets say it is 20c per kwh=$17

Sorry. I do not want to calculate mining profits.
I only want to know - who is paying today these $17 bucks per transaction

OK, I know (I think that I know) who is paying.
His name is John Smith and he thinks that his transactions are low-cost and bitcoin is awesome.
He also thinks that bitcoin will cost tomorrow more than today.
He knows nothing in cryptography, math, physics and https://en.wikipedia.org/wiki/Conservation_of_energy.
He thinks that he can gain infinite profits only holding some digits in his computer for infinite time.

UPD:
OK, may be one can argue with $17 per transaction.
Let us go one step back.
Who is paying [%your number][%your currency] for 83.33kWh per one transaction?

Every holder of Bitcoin is paying, by having their coins depreciate 10% each year, perpetually, due to the cost of PoW mining. Though we have been lucky so far, since the inflow of capital far outpaces this depreciation in the past. But at some point, the inflow of capital will be unable to keep up, and we will see the depreciation, we are possibly seeing it right now.