The growth of Bitcoin mining in America is due to miners partnering with oil and natural gas producers to use the energy that would be otherwise wasted. Instead of excess natural gas being flared, it's being used to run Bitcoin miners [1].
Everyone should read Lyn Alden's "7 Misconceptions About Bitcoin" [2], where she addresses the energy use; here's an excerpt:
Furthermore, a significant portion of the energy that Bitcoin uses could otherwise be wasted. Bitcoin miners seek out the absolute cheapest sources of electricity in the world, which usually means energy that was developed for one reason or another, but that doesn’t currently have sufficient demand, and would therefore be wasted.
Examples of this include over-built hydroelectric dams in certain regions of China, or stranded oil and gas wells in North America. Bitcoin mining equipment is mobile, and thus can be put near wherever the cheapest source of energy is, to arbitrage it and give a purpose to that stranded energy production.
Bitcoin mining converts the output from those cheap stranded sources of energy into something that currently has monetary value.
[1] https://www.coindesk.com/energy-giant-equinor-to-cut-gas-fla...