Ethereum's energy consumption from 2015 until it moved to a proof-of-stake (PoS) consensus mechanism late last year is equivalent to that used by all of Switzerland in just a year, according to the University of Cambridge's Centre for Alternative Finance. The Cambridge Blockchain Network Sustainability Index estimates that Ethereum's consumption totaled 58.26 TWh between 2015 and the Merge. Ethereum's energy consumption is now orders of magnitude smaller than Bitcoin's. However, CCAF is careful not to take a view on which algorithm might be better or worse. CCAF estimates Ethereum will consume 6.56 GWh of electricity annually.

(By Ian Allison)