[adamrezich]

you really think that every credit card reader in the country, every ATM, every computer and piece of electronics at every branch of every bank, and all of Wall Street and everything, adds up to less than the sum total of Bitcoin mining in the country, in terms of energy usage? how could this possibly be the case? I'm not even a Bitcoin guy and this is absurd on its face.

[jcranmer]

Yes.

This article gives an estimate of about 2% of all electricity usage going to bitcoin mining. All data centers in the country combine to a similar ballpark in energy usage (another comment states 1-3%). Finance accounts for 20% of US GDP, so we'll be charitable, round up its usage of datacenters to 50%, to get about 1% of electricity from financial data centers.

There are about 6.7 million employees in the financial sector [1]. Assume everyone has a computer with a 600W power supply at full bore for 12 hours a day [2]. That comes out to about 18 billion kWh of electricity a year, which is (checks math) 0.425% of US electricity consumption [3]. Sure, I'm not accounting for all the PoS systems at every retail location in the country, but they're going to use far less energy than even the overspecced numbers I'm using.

So overall, this comes out to about 1.5-2% of US electricity usage going to the financial sector, less than Bitcoin mining. Also remember that magically switching everything over to Bitcoin would still require all those PoS systems, not to mention large fractions of Wall Street and bank branches and whatnot, so this isn't really a fair comparison overall. And some amount of the financial sector includes cryptocurrency companies already.

[1] https://www.bls.gov/iag/tgs/iag52.htm

[2] This basically comes out to a decently powerful computer being used at max spec for an 84 hour work week. A generous overestimate, I'd hope you agree.

[3] https://www.eia.gov/energyexplained/electricity/use-of-elect...

[lgleason]

Right, but the financial system is actually used by most people in the US. Bitcoin, a small fraction of that...and this figure does not include all of the energy expended to process bitcoin transactions.

[beau_g]

You are comparing the transaction cost of credit cards/banking/trade to the transaction cost + infrastructure cost of bitcoin. Credit card companies, banks, financial institutes have millions of employees that drive to work, HVAC in their offices, etc. that is not required with bitcoin. This is ignoring all of the rest of OPs point that preserving the dollar system has countless other external costs.

[ipdashc]

I would think those employees exist because people demand a whole bunch of services from the financial system, like fraud protection, chargebacks/disputes, customer support, and so on. If you stripped down Visa or whatever to its bare minimum of just processing online transactions, I'm sure it could do it pretty efficiently. Conversely, if all our money ran on Bitcoin, I'm sure most people would still want to interact with companies that provide extra services and support on top, and then you'd be back in the same place.