The market for NFTs soared last year to $44 billion. This brought a lot of attention to Ethereum, the blockchain network where most NFTs are bought and sold. It also brought a lot of attention to something else: the massive energy wastefulness of cryptocurrency mining. Both Bitcoin and Ethereum, the two largest cryptocurrencies, rely on a consensus mechanism called “proof of work” to maintain a time-ordered ledger of transactions. Crypto miners are at the core of that process.