Yes, it will take a while to reach $50,000. Many years.
But it will hit $5000 within the next 6 months.
A sustained $5000/BTC price would drive mining to attempt to consume about 0.3% of world wide power production. That is a lot, but at least is it
possible.
How much does the banking sector consume of world power, eg servers, atms, branches, minting cash, credit cards etc etc. I think that BTC can repalce 50% to 10% of banking finance sector at least. The Banking sector must be at least 5% and so will consume about 5% of power. This 0.3% is ok. Also mining as heating will be a very good using in cold countries as the power will be already paid for.
Having said that A POS such As Peercoin could take over at this point as it does not face the mining head wind