[Feeble]

It's wrong to see it as power consumption per transaction. The power used is to secure the monetary network. So for VISA you would have to factor in all their offices, running systems, employees, security etc. used to secure their financial network.

[floatingatoll]

Those resources use a significantly lower total amount of energy per annum and per transaction relative to cryptocoins, as they do not depend on brute force scans of cryptographic hash spaces in order to perform and secure transactions.

[nicbou]

I'd still assume that Visa uses less power than Austria.