According to this web page: https://arstechnica.com/tech-policy/2017/12/bitcoins-insane-energy-consumption-explained/
...one bitcoin transaction consumes about 250 kWh of energy.
Is this the marginal energy cost of each additional transaction, or the average electricity cost of continuous mining (that would happen no matter whether there are transactions or not) divided by the relatively low transaction count?
What is the marginal energy cost of one additional bitcoin transaction? I.e. if the number of transactions would increase by one, by how much would the energy consumption of the bitcoin network increase?
Would the energy consumption of the bitcoin network double if the number of transactions doubled?
If each bitcoin transaction consumes 250 kWh, that would seem absurdly high. I do several hundred ordinary bank or card transactions per year, making the energy use about 75 000 kWh per year if I used bitcoin, which is 25 times higher than my current direct electricity use and probably still 10 times higher than my current direct and indirect electricity use combined.
Related: https://skeptics.stackexchange.com/questions/39910/does-one-transaction-on-bitcoin-require-215-kwh (I initially considered asking this on Skeptics, but they seem to have a habit of closing perfectly valid questions).