Electricitymaps used to supply marginal emissions data. They stopped doing it because they realised it was driving bogus research. They're right. NYT, Gabriel Dance and a recent Harvard paper - all on Bitcoin mining - all used marginal emissions to come up with bogus clean energy numbers for Bitcoin, now debunked in a 2025 Cambridge study https://www.electricitymaps.com/content/from-power-markets-to-reality-does-the-marginal-power-plant-really-exist(Daniel Batten)