Thank you for the response. Per the source in cited for Solana's energy use per transaction, the number in kWh is 0.00051:

https://solana.com/news/solana-energy-usage-report-november-2021

If you're claiming that when Solana's transactions scale to the same volume as Visa's their energy use will be comparable, I would note that while Visa currently processes MUCH more transactions, Solana's per-second processing capability has already matched theirs, meaning the Solana network doesn't need to grow exponentially to process their 138B transactions (Visa claims capacity of 24k/sec, in reality they process less than 2k/sec).

Another important point: the actual Visa network is just one stop on the long inefficient odyssey of an online credit card purchase. It also goes through an acquirer like WorldPay, various data miners, the issuing bank, et al before going back through the whole sequence to the merchant.