This author is getting the causation backwards:
> Is there a correlation between power consumption and the cost of bitcoin.
Yes, of course there is a correlation, but he's getting the causation entirely backwards.
The profitability of mining is directly proportional to the price of bitcoin, because you're paid with 12.5 Bitcoins per block. But your costs are fixed in USD -- you pay for electricity costs, per kilowatt. Therefore as the Bitcoin price goes up, it's profitable to run that many more miners, to produce that many more hashes, until you fill up the profit with electricity costs again.
So the price of Bitcoin determines the hashrate, not the other way around, like he's presuming here:
> If this correlation is strong enough, it means the Bitcoin will always be bounded by the cost and availability of electricity.
This guy also assumes that miners are paying the average electricy price in the US and China. Miners pay nothing like that. California electricity rates are around 15¢/kW. Central Washington is 2-4¢. That's 6-7x cheaper. The same is true for China.