Well... The idea now is to have a line of solar panels on top of the wall, sell the electricity to Mexico and that way we ber the wall money back..

Some problems to this is that at best we will get 2 billions from selling the electricity, the wall is goign to cost over 10 billions and to carry the electricity we will need at least 2 billions of infrastructure along the wall...

In the positive side... those mexicans probably just steal the panels and walk back to their country instead of invading us... so at least the panels will motivate them to turn back to where they came from...