“What Bitcoin does is run a computerised lottery, in a process called “mining.” Bitcoin miners guess a number. They take their guess, they combine it with a block of transactions that are waiting to be processed, and they do a simple calculation on them. If the calculation gives a small enough number, the miner wins six-and-a-quarter fresh new bitcoins! And their block of transactions is added to the public blockchain. The more guesses you make, the better your chances. In June 2020, Bitcoin miners were making 100 quintillion guesses every second. This used as much electricity as all of Austria.45 This is called “proof-of-work” — though it might better be termed “proof-of-waste.” Blocks come out approximately every ten minutes. If miners win coins too often, the difficulty goes up, to slow the system down — so the miners have to add more computers to compete. This results in spiraling electricity use — Bitcoin is, literally, anti-efficient. The point of all this waste is to secure the blockchain — the threat model is that nobody can change the blockchain without wasting at least as much electricity. The Bitcoin mining system is incredibly slow, and very hard to scale up. Bitcoin now consumes between 0.1% and 0.5% of all the electricity in the world — for the same seven transactions per second, worldwide, that it could do in 2009, when it was just running on Nakamoto’s desktop PC. Bitcoin is the most inefficient payment network in human history.”