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Comment by gus_massa | Hacker News Reader

> The problem, of course, is that if it takes an Argentina's worth of electricity to run Bitcoin now, how does the world manage if Bitcoin has a 10 or 100 times greater market cap?

The amount of electricity is not proportional to the market cap. It's proportional to the difficulty. You can create a copy of bitcoin where the difficulty is keep very low and add a very big amount of transactions and be very easy to make fake blocks and forks and other nasty stuff. The difficulty is adjusted to keep the time to find a block somewhat constant.

One problem to handle a bigger marketcap is the block size. One solutions is to increase the block size, another is to use a secondary chain. I'd like to increase the size, but most people prefer the other.

Also, when you add the energy that goes directly from sun light to soy beans, I think that we are in Argentina still using a little more more energy than bitcoin.

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>The amount of electricity is not proportional to the market cap This misses the point of the argument, which is to say that if the market cap of bitcoin goes up, the marginal benefit of mining by definition goes up. This in turn drives up demand for electricity, until the marginal cost of additional mining units and associated power equilizes. That's not to say that there isn't a benefit to a more efficient proof-of-work scheme, as in theory if the scheme can support _all_ future and current transactions like the current banking system, then there's a cap on energy consumption. However, what OP points out is that the speculation and monetary utility of Bitcoin both act to increase power consumption due to basic economic forces.

>Also, when you add the energy that goes directly from sun light to soy beans, I think that we are in Argentina still using a little more more energy than bitcoin.

This is a non-sequitur. The point of using Argentina is to illustrate that in verifying transactions, Bitcoin uses as much energy as millions of people lighting their homes, watching television, running air-conditioning, heating water, charging their phones, etc etc etc. Nobody is claiming that Bitcoin consumes more metabolic energy or solar energy, OP's just highlighting that Bitcoin's electricity costs are potentially unsustainable.

> The amount of electricity is not proportional to the market cap. It's proportional to the difficulty.

But the difficulty is proportional to the amount of miners, which is proportional to the profitability of mining, which is proportional to the price, which the market cap is proportional to (i.e. price x supply). So electricity is indirectly proportional to the market cap.

> One solutions is to increase the block size, another is to use a secondary chain.

Those solutions don't address the energy spent on mining, they just allow more people to transact. The former means more transactions (more fees), the latter means fewer but more expensive on-chain transactions (more fees). Either way I believe the block reward (and thus the amount of energy miners will throw at getting that reward) will be roughly the same, it'll be a function of how much people value and want to use bitcoin.

"It's proportional to the difficulty."

You just confused the amount of electricity it takes to mine one block, vs, the amount of total electricity all miners spend.

And the total amount of electricity is indeed proportional to the market cap. (with a constant of proportionality being halved every 4 years).

As the original poster said, it is ridiculous that we still have to debate this.

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