Donald Trump’s plan to build a solar border wall, explained with math

Last week, President Donald Trump insisted that he really isn't joking about putting solar panels on the border wall he’s promised to build between the United States and Mexico.

“There is a chance that we can do a solar wall. We have major companies looking at that. Look, there’s no better place for solar than the Mexico border — the southern border,” he said. “And there is a very good chance we can do a solar wall, which would actually look good.”

When Trump first pitched the idea of a solar wall at a meeting with Republican Congress members at the White House in June, he claimed that the idea was his (it wasn’t) and that the energy generated by the panels could cover the cost of the wall.

Now that it seems he really wants solar panels on there, we decided to do the math on this possibility of the wall “paying for itself.” That would, theoretically, help him sell the plan to fiscal conservatives, among others.

A border wall would be really, really expensive

As Vox’s Dara Lind and Tara Golshan explained in May, Trump faces a multitude of obstacles in building more border wall (there are already 654 miles of fence and wall down there). Chief among them is convincing Congress to pay for it. While Trump maintains that he will somehow get Mexico to eventually pay for the wall, American taxpayers will have to foot the bill initially.

The US-Mexico border fence stops while passing through farmland near Fort Hancock, Texas. Throughout vast stretches of West Texas, the current fencing starts and stops along the bank of the Rio Grande, which is often nearly drained due to irrigation for crops. Photo taken on October 14, 2016.