@stevenroose So that works out to 5300 joules / transaction. That seems rather high for a centralized system: presumably they're actually counting overall usage, including overheads and energy used by network connectivity, rather than marginal energy usage per transaction.
Remember that 5300J is the energy used by 1s at 5300W. That's something like a dozen high-end computers running flat out.
@pete Well it involves the payment terminal, the 5 seconds of heating for the person standing next to the payment terminal, all the internet devices powering the 3-5s connection between the terminal, the VISA server, the server of the bank that issued the card 😅
@pete @stevenroose I love how articles on Bitcoin's energy usage often straight out divide the estimated power consumption of miners by on-chain transactions per second.