Why on earth does the mining have to use more power than a medium size country as the price rises?
Because the miners get paid with block rewards in bitcoin. As the price of bitcoin rises so does the block reward.
And as long the mining gear produces more rewards than the power to run it costs, it will stay online. And at, say $500K per coin and 12.5BTC/block that would be like $900M rewards/day or ~$330B/year. A large amount of that would be going into paying the electricity bills.
This is actually a really interesting point. I wonder then if the adoption curve is retarded by the block reward. I guess then any order of magnitude moves (such as i speculated) are some 10-20 years off.
Thats going to test some patience!
You have to consider miners getting more effienct very fast.
A miner that is delivered a fee months late is worthless on arrival(unless bitcoin value spiked during those months) that's how fast miners advance. This will continue to happen at least until miners catch up with the current line of semiconductor technology, which is 14nm I believe.
As long as ASIC chips are lagging behind on chip technology they will have a very rapid growth compared to moores law because catching up is easier than having to design new hardware from scratch.
Also you need to consider the limitations to the actual manufacturing. Miners can want more equipment all they want but if the miner manufacturers can't keep up with producing them, the miners can just wait forever.
There's only so much miners that can be produced in a certain timeframe so even if bitcoin value goed through the roof a couple of times, the energy consumption will not be requiring the output of three suns, because simply not that many miners can be produced that sudden.