Direct link to paper: https://www.pnas.org/doi/10.1073/pnas.2304318120

Not my field but takeaways from a quick glace are that they note that the more energy dense they make it the worse it is at being concrete, and that their 10kwh number needs 45m³ of concrete. That would be 15x15x0.2m or like 55ftx55ftx8in which isn't crazy but it's a pretty decent amount.