The amount of electricity used per Bitcoin transaction is stupidly high
While it may not cost a lot of power to broadcast a transaction to the Bitcoin network, once you take into account all the mining that occurs the cost per Bitcoin transaction is a remarkably high!
Here is a back-of-the-envelope calculation that will give us a reasonable lower bound on the amount of electricity used per transaction. One of the ASIC miners released 2016 claims that it expends 0.1J / gigahash (GH) and this is considered very efficient. Currently the hash rate is about 1,500,000,000 GH/s. Thus if everyone was using this particular machine the combined power would be 150,000,000W or 150MW. In a day (24 hours) this equates to 3600MWh
The number of transactions is currently sitting at about 225,000 per day. Dividing 3600MWh by 225,000 yields a cost per transaction of 16kWh/transaction!
This is just a lower bound for the following reasons:
- this only holds if every miner is using this particular machine which is top of the line and considered very efficient.
- this does not take into account electricity which is not used for mining but merely for running nodes
In fact this article puts the figure at 46kWh per transaction. This is enormous. It is about 1.57 American households worth of electricity per transaction. To put it another way, each transactions costs the same as turning on your dryer for a little over 15 hours.
I don't know about you all but I think this clearly shows that Proof of Work may ultimately be a flawed idea and that a successor algorithm (Proof of Stake?) is an imperative.