[stale2002]

Bank of America also puts carbon in the air in order to make your debit card work. Those offices cost a lot of money, resources, and carbon in order to keep the lights on and make those databases work.

How are crypto-currencies any different than that?

[bpodgursky]

This conversation has been done a million times, and I don't feel like going through the motions again when it's so easy to look up.

The fact is it is different

(1) fundamentally, because BoA would use 0 electricity if it could, while it will ALWAYS be worthwhile to spend a certain fraction of Bitcoin's transaction volume on electricity in order to capture transaction fees, and that will ALWAYS involve pointless hashes. GPU /ASIC efficiency gains will only drive more miners to mine.

(2) obviously, just look at the comment chains on previous posts for numbers (https://news.ycombinator.com/item?id=14751971); bitcoin burns a stupid amount of electricity to process a minute fraction of BoA's volume

[stale2002]

Crypto currencies would absolutely use zero electricity if they could too.

There are efforts RIGHT NOW to solve this problem. So just like how BOA wastes electricity right now, and is trying to reduce its electricity use, so too are cryptocurrencies.

For example, one way to do it is to power the blockchain via "wasted" electricity from other sources, that was going to do nothing anyway. For example, a heater literally sends electricity through wires, and "wastes" that energy to create heat. One could imagine a heater that uses the electricity/heat from mining for "free".

Or even at a more basic level, imagine a electric dam, that produces so much power during certain times in the day, that it has to sell it for negative prices on the market. Thats Free energy right there!

Another example is Proof of Space algorithms. The way it works is instead of using GPU heavy hashing algorithms, you use "Space" intensive hashing algorithms.

The reason why you do this is because there is a TON of extra hard disk space that is just lying around doing nothing. We could take that extra space for "free" and use it to secure a blockchain (while allowing the user to reclaim the space at any time with no effort), and it would cost very little electricity.

[jstanley]

> For example, a heater literally sends electricity through wires, and "wastes" that energy to create heat. One could imagine a heater that uses the electricity/heat from mining for "free".

Right, but once people do that, mining becomes more efficient. If mining becomes more efficient, more people start mining, then the difficulty adjusts, and then you're back at the beginning.

It's not a bad thing: efficiency gains are good. But they don't reduce the total energy expenditure, because they incentivise increased mining.

[stale2002]

No, mining does not become more efficient. It make it unprofitable for people to mine bitcoin, because they are competing with people who are using free electricity.

The only people who would be mining are the ones who are spending 0$ on electricity, because the electricity would otherwise be wasted.

By heater, I meant literally a heater in someone's house.

The idea is that the only electricity that would be spent on the blockchain is electricity that was going to be sent down the drain anyway.

[jstanley]

I meant "mining becomes more efficient" in the sense that using it as a heater is an efficiency gain over not using it as a heater. I didn't mean to imply that legacy non-heater miners also become more efficient.

Intuitively, you're right. However, I read an article (can't find it now, still looking) that presented a convincing case that if there is $X up for grabs for doing a certain amount of work (mining), then the amount of work that is done increases until $X is being spent on the work. So if you're getting heating out of it as well, X increases, but that just means more mining is done until it's no longer marginally profitable.

But intuitively you're right. So I don't quite know where the mistake lies.

[IanCal]

> It's not a bad thing: efficiency gains are good. But they don't reduce the total energy expenditure, because they incentivise increased mining.

I think it's a stretch to say the two are perfectly linked.

If you dropped someone's electricity price in half, would they buy twice the equipment to mine? If you dropped it to 1%, would they buy 100x as much equipment?

[mulmen]

That's not exactly the question. It's more like if you dropped the price of electricity to 1% would 100x as many people participate. The answer to that is generally yes.

[IanCal]

Would they? There are still significant fixed costs for a risky reward. A quick way of looking at the extreme end is: does everyone with free electricity do it?

[panda88888]

Crypto currencies will never be as energy efficient as a traditional financial network with trusted players because of the need to calculate pointless hashes (or other variants of proof of work) in order to resolve trust and consensus issues.

For BoA (or other financial institutions), simply sending a message through the trusted financial network saying "I pay you $5" is sufficient. Whereas for BitCoin (or other crypt currencies), a difficult hash has to be calculated that takes many orders of magnitude more energy.

[cperciva]

Bank of America processes orders of magnitude more transactions per ton of CO2 emissions.

[DoctorBit]

LOL, that's an interesting new metric for financial transactions - I like it! I sure hope Vitalik et. al. can pull off Casper as advertised.