> FWIU we already have enough abandoned mines in the world to do all of our energy storage needs?

Here's a prompt for this one, for the AI:

"Let's think step-by-step: how much depth or volume of empty mines are needed to solve for US energy storage demand with gravitational potential energy storage drones on or off tracks in abandoned mines? Please respond with constants and code as Python SymPy code with a pytest test_main and Hypothesis @given decorator tests"