Vacuum Insulated

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

I understand the emptiness to be a perfect insulator? Would the concept of earth's atmosphere gap created power differences be used as fuel / energy supply humans? Perhaps the complete circuit in a vacuum would be too much, a double vacuum insulation?

V = Ed if the top is 6 " bottom to top: V (above) - V (bottom) = E1 * (x + 6) - E2 * (x), having to Earth to 0 => V (up) = E1 * 6, where E1 is the field electric on top

Vacuum Insulated

Vacuum Insulated