How do you think transactions are verified? There's a limit to the number of transactions per block, and each block takes ~10 minutes to mine. So; ~2000 transactions/block, 600 seconds, 0.3 seconds/transaction. How much energy does the global bitcoin network use in 0.3 seconds?

About 700 KwH, far as I can tell. (Based on 76.87 terawatt hours annually in 2020, as an estimate for bitcoin). A house uses ~1000/month, ballpark.