Orphan blocks on bitcoin network waste 16 GW

A new PNAS Nexus paper has shed light on a major source of hidden energy waste on the bitcoin network. Here, miners compete to solve a complex mathematical puzzle. The miner that solves a puzzle first is rewarded by the network with a block: new bitcoins plus transaction fees. An accidental fork occurs when two different miners solve the puzzle at almost exactly the same time. Because it takes a few seconds for a winning block to be announced to the rest of the network (called the propagation delay), a second miner might successfully mine the same block before they find out someone else has already won it. Eventually, the network chooses one block to keep and discards the other, which is called an orphan. The energy used to mine that orphan block is essentially wasted because it doesn’t contribute to the security or the history of the network’s official ledger. As part of the study, the researchers developed a model to calculate how often these forks happen based on the number of…