[dojomouse]

For what it's worth I think the energy related claims are pretty weak. Technically you can store energy in the kinetic energy of the mass moving at speed, and with diamagnetic ('quantum') levitation the losses are very low... however the costs, overall efficiencies, and dynamics make it barely interesting as a theoretical exercise, and totally worthless as a practical one.

Powering with PV on top of the tube, on the other hand, should be entirely realistic (at least on an average consumption vs average generation basis), and the incremental PV cost will be really low since you'd install it as part and parcel of the tube.