Cryptocurrency is very environmental-unfriendly.

https://www.telegraph.co.uk/news/2018/02/12/iceland-set-use-energy-mining-bitcoin-powering-homes/

Iceland's crypto miners will consume more electricity than the residents and Iceland's government is considering taxing crypto miners to keep the electricity's demand and cost low.

Cryptocurrency's technology, the blockchain, profligates a lot of electricity which can otherwise be put to a more productive use.  In a nutshell, a computer instance is replicated across many servers in the crypto network whenever a transaction occurs but only one server is able to verify and process the transaction successfully within a specific time period, thereby, causing huge electricity wastages in other unsuccessful servers.  This kind of methodology will cause electricity shortages for normal usages and electricity costs will start to increase over time for ordinary residents.

This is the primary reason for a crypto miner to house the mining servers or rigs in a low-cost energy country but the local residents will pay more for electricity because of crypto mining.