In a vacuum,what is the difference in voltage potential between earth ground and 6' elevation?

Question

I understand a vacuum to be a perfect insulator? Would the concept of ground to atmosphere vacuum originated power differentials be of use as power/energy supply to humans? Perhaps the entire circuitry would be inside a vacuum too, a double insulated vacuum?

Answer 1

V = Ed

if top is 6' above bottom:

V(top) - V(bottom) = E1 * (x + 6) - E2 * (x)

taking earth ground to be 0 => V(top) = E1 * 6

where E1 is the electric field on top