Per-transaction energy costs can be derived by dividing total network energy use by total number of transactions, for each payment method under consideration.

I rely on the energy use figures provided by Solana, Visa, PayPal, et al because they are commissioned by independent auditors (I link to Solana’s). And sure, I suppose all of the auditors could by lying, but with Solana at least we can get a gut check on their numbers by looking at the number of validators active on their network, their individual transaction processing capacity, and the hardware configuration that capacity implies. From that we can derive a fairly good estimate of each validator’s energy draw in watts.

It’s much easier to come by up to date numbers for Bitcoin energy use because of the volume of academic research that’s been published on the subject. Google Scholar and Statistica are both good sources.

My purpose here is not to persuade those determined to hate this technology. I promised to explain the data I used to evaluate the environmental impact of adopting Solana NFTs in Cinder; I am fulfilling that promise.

I welcome data from other sources, but when I’ve invited skeptics to share it with me, they shout that it’s not their responsibility to do the research. I concur. But if they won’t join me in seeking fact-based arguments for or against, I have nothing further to say to them on the subject.