if we stuck with GPU mining. then yes todays hashrate would require 140% (1.4x) (the world and then half again) electric supply
but the community have mitigated against that with asics.
currently today with this current generation of asics (not last gens bad mathematical statistic) we are at LESS than 0.1%
and if rumours are true of a 7nm asic of 28th and 0.8kwh... we would be at 0.3% at current hashrate
which means the hashrate can triple from octobers suggested 7nm release.. and still be below this summers 0.1% international usage
now. putting that stuff aside.
power companies make excess energy. they love it when industry buys the excess. and they can expand because that excess was waste is now paid = 100% profit of the waste for the energy company. so they have more funds to expand and add more generators/solar
thus help grow more production due to growing demand. thus the percentage used doesnt exceed percentage generated.
and putting that aside
we are at 20twh so let pretend 50% is in china (its less but shh dont poke the propagandists)
10twh bout out of chinas 830 EXCESS
that means using current asics. hashrate can go 83x and still be of no concern.
using next gen asics 249x
that means at lets say 50exa now
things can go to 12.25 zetahash (12450exa) before bitcoin even starts to touch regular consumed utility.
which is plenty of time and profitable income for power companies to expand
now i know people will shout limited supply if water for hydro.
ill just leave these crap pictures here.. hint.. recycle the water. dont let it just flush downstream