The total network of computers plugged into the Bitcoin network consumes as much energy each day as some medium-size countries — which country depends on whose estimates you believe. And the network supporting Ethereum, the second-most valuable virtual currency, gobbles up another country’s worth of electricity each day.The energy consumption of these systems has risen as the prices of virtual currencies have skyrocketed, leading to a vigorous debate among Bitcoin and Ethereum enthusiasts about burning so much electricity.

https://mobile.nytimes.com/2018/01/21/technology/bitcoin-mining-energy-consumption.html