Is this correct

[eece_ret]

Bitcoin has been in the news a bit of late.  One item in particular though caught my eye.  Electrical use per transaction.  From my reading, a Bitcoin transaction on average consumes >700kwh.  Mind you my family of 4, in a hot climate, air conditioning crushing it AND an electric car (only charged at home) consumes about 1000 kWh per month.  Bitcoin >700 PER TRANSACTION????  Can that be right?  How many BC transactions occur in a day?  

[WkdPaul]

* thread moved to the Folding@home, Boinc, and Coin Mining section *

[HanZie82]

2 minutes ago, eece_ret said:

average consumes >700kwh

700 000Watt/hour for a transaction.

Hell naw. Thats higly unlikely, someone must've confused themselves with them numbers. Like almost every journalist of today's world does.

[tikker]

That's sounds about correct. Bitcoin mining's current energy consumption is about 134 TWh per year. We currently see an average of number of transactions per hour of 10174, which translates to just shy of 90 M transactions per year (89 124 240). We can then do the maths:

 

(134 TWh / yr) / (89124240 transactions / yr) = 0.0000015 TWh / transaction

 

If we simplifiy the powers of 10 that comes down to 1.5 MWh per transaction currently.

 

Sources:

https://cbeci.org/

https://bitinfocharts.com/bitcoin/

[RollinLower]

bitcoin mining uses a lot of energy. so yeah, i wouldn't be surprised if this turned out to be true.

[harryk]

Yes this is true. However, it's important to understand the nuance of this metric.

 

Miners consume power to mine. They receive bitcoin paid as fees for transactions, but are also rewarded for each new block on the blockchain. The block rewards are significantly greater than the transaction fees. While key to the longtime operation of Bitcoin, currently the transactions are more or less a footnote on the blockchain when measured in value to miners.

 

The current Bitcoin block reward is 6.25 BTC (or ~$230,00). By design, approximately every 10 min a new block is solved and rewarded. Thus every hour $1,380,000 in value is earned via block rewards by the collective of miners, consuming ~6GWh in the process (about ~$0.23 earned per kWh).

 

tldr; the power isn't really being used to complete transactions

[tikker]

7 hours ago, harryk said:

Yes this is true. However, it's important to understand the nuance of this metric.

 

Miners consume power to mine. They receive bitcoin paid as fees for transactions, but are also rewarded for each new block on the blockchain. The block rewards are significantly greater than the transaction fees. While key to the longtime operation of Bitcoin, currently the transactions are more or less a footnote on the blockchain when measured in value to miners.

 

The current Bitcoin block reward is 6.25 BTC (or ~$230,00). By design, approximately every 10 min a new block is solved and rewarded. Thus every hour $1,380,000 in value is earned via block rewards by the collective of miners, consuming ~6GWh in the process (about ~$0.23 earned per kWh).

 

tldr; the power isn't really being used to complete transactions

This is a good explanation of the nuance. The blocks exist to hold confirmed transactions though and in principle I wouldn't consider an unconfirmed transaction complete. While you don't explicitely spend this power to do the transaction, technically it isn't complete until confirmed, so you still sort of spend the energy to for/on the transactions.

[eece_ret]

Thank you!  So its a situation of "does it use 700kwh/transaction).

 

Short version:  Pretty much

Long version:  Kinda but not really

Sound about right?

[tikker]

17 minutes ago, eece_ret said:

Thank you!  So its a situation of "does it use 700kwh/transaction).

 

Short version:  Pretty much

Long version:  Kinda but not really

Sound about right?

Miners can technically mine so-called "empty" blocks without transactions, which will fortify the blockchain because it confirms earlier transactions more, but the transaction fees do incentivise including transactions in the block. The computational power required is not meaningfully different for an "empty" block or a "full" block. Mining can thus continue without transactions, but since most blocks still have transactions in them it's decent enough back-of-the-envelope math for illustrative purposes.

 

It's like kg of CO2 per person per km figures for travel by plane for example. It's not explicitely emitting extra CO2 just because you boarded the plane, but it provides context to compare it to other means of transportation