My friend and colleague Simon Michaux joined the course today, and in the discussion after my lecture on Ravel, he told us of his work to quantify the minerals needed to create a non-fossil fuel based economy. The bottom line is that the minerals needed far exceed our current output of minerals, and in many cases exceed the minerals available in the Earth's crust.
He agreed to share his Excel file with us, and I hope over time he'll also port his data and analysis to Ravel, where it will be far more transparent than in Excel, even given the care Simon has taken to make the data auditable.