Would it be feasible to build a solar wall along the southern border?

January 17, 2019 7:29 PM

In light of the current federal shutdown in the United States, is there any way that a solar wall could be used to turn this crisis into an opportunity to expand green energy capacity in the United States? It would take a solar field roughly 10 or 11 miles in width to provide enough solar power to power the entire United States. It there any way this could work?

It would address so many issues--end the federal shutdown, put Americans to work in green energy jobs, give both parties a political (and bipartisan) win, and end our reliance on fossil fuels. I am not sure if the shutdown over the wall is grandstanding, idiocy, or subterfuge--but at least it could be a way for democrats to turn a ridiculous and xenophobic waste of resources into a long-term investment in our economy and future. Why wouldn't this work?

posted by metasunday to Law & Government (14 answers total)

Any wall along the southern border would cause the same problems in regard to disrupting natural habitat and creating issues with eminent domain. There are plenty of places to locate solar energy fields in the US without creating disruptive infrastructure.
posted by Autumnheart at 7:40 PM on January 17, 2019

Jigar Shah proposed exactly that last week. He took it a step further: selling the power to Mexico, and thus provide cover to Trump because Mexico would be "paying for the wall".

Jigar Shah: Give Trump Money for a Wall by Funding the Green New Deal [LinkedIn]

He's since said he was kind of joking, but I'm not so sure.
posted by intermod at 7:57 PM on January 17, 2019

There is loss in transmission of electrical power; this is proportional to distance, so powering NYC from a solar cell thousands of miles away will waste a lot of power. Further, the US doesn't have a single grid, it has four (East, West, Texas and Alaska) and the Eastern grid is about 2/3 of the power, but doesn't touch the Mexican border.

Further to that, even if the grids were connected, there would still need to be massive new power transmission infrastructure built, because right now power is generated all over the place; say, Houston gets most of its power from coal or wind or gas or nuke plants relatively nearby. The grid in the area can handle Houston's power demand with enough spare capacity to handle shifts if there are spikes nearby. If, instead, the power grid was a wall on the Mexican border, then the grid in the Houston area would not only have to handle the local power needs plus a little extra capacity, it would also have to handle all the power needs of the cities whose power is coming from the border past Houston, ie most of the east coast.
posted by Homeboy Trouble at 7:57 PM on January 17, 2019

there would still need to be massive new power transmission infrastructure built

Came here to say this. A plan to build a giant solar farm in the Sahara to power Europe fell apart because they couldn't solve the power transmission issue.

Also, I suspect a solar wall would be neither a good wall nor a good solar farm in a place we don't need them.
posted by bluecore at 8:05 PM on January 17, 2019

I am not sure if the shutdown over the wall is grandstanding, idiocy, or subterfuge

You can be sure that it is 100% idiocy and bigotry. It is not a technical problem in search of an honest solution, it's a physical statement that all Mexicans are rapists.

On the one hand, it wouldn't work because (almost all) Democrats don't think all Mexicans are rapists and so don't want to spend money loudly proclaiming that they are.

On the other hand, it wouldn't work because it would require the Republicans to agree to spend something north of a trillion dollars on solar power.
posted by GCU Sweet and Full of Grace at 8:12 PM on January 17, 2019

We need to solve the demand problem before we can power the whole country with PV. Currently, we pretty much make solar power based on whether or not the sun is hitting the panels at any given moment, rather than based on how much power is actually needed. Until we can store and release all that energy as necessary, solar can only supply a fraction of the country's power. People are working hard on this problem but we're not there yet.

Also yeah, transmission is an issue. You want to spread the production around geographically because it's hard to ship electricity across the entire country; you need a ton of infrastructure and there are inevitably transmission losses.

Also, a solar farm is not a wall in any meaningful sense. You'd need to build a wall to keep people out of your solar wall. There are code requirements about that kind of thing, to stop hooligans from getting into them and frying themselves to a crisp.
posted by Anticipation Of A New Lover's Arrival, The at 8:29 PM on January 17, 2019

a lot of the border footprint is in a floodplain. not where you want to build anything, really.
posted by eustatic at 9:54 PM on January 17, 2019

The solar wall idea has been considered, mocked up, and rejected already.
posted by ejs at 10:05 PM on January 17, 2019

a lot of the border footprint is in a floodplain. not where you want to build anything, really.

Significant portions are also mountainous and not practical to maintaining infrastructure. Even DHS's systems commonly don't function (ground sensors, for example), and they have few resource constraints because Congress appropriates DHS more money every time an agent sneezes.
posted by migrantology at 7:40 AM on January 18, 2019

Putting critical infrastructure that close to a foreign border would make it massively at risk for attack. Who's going to guard it? Border Security? The military? TSA? Would the cost to defend it be offset (and thensome) by the income it would generate?

The security concerns and on-going cost concerns would likely lead to the whole idea being shouted down.
posted by vignettist at 7:43 AM on January 18, 2019

I mean even if the wall was one single continuous thousand-mile-long array (which would be a nightmare to maintanin, the ground moves around too much) you could go through it with nothing more than a screwdriver (just pull a mod) or a sawzall (a mixed-substrate demo blade would make short work of the glass-and-aluminum construction of a solar array) and a willingness to risk fatal electrocution. Also you can either duck under the bottom edge of the array, or just walk up it and then climb down the other side. By the time you had hardened your array enough to function as a useful barrier, you would probably have been better off just building a wall in front of it.

My source here is that I work in solar and I help build and design these things. A solar array is just not a wall.
posted by Anticipation Of A New Lover's Arrival, The at 9:29 AM on January 18, 2019

The solar panels, which have to face south, would be on the Mexico side. They're also rather delightfully breakable: a well-aimed rock or slingshot pebble can take one out, and enough knocked out along inverter strings can render the entire installation useless.

Any attempt to sell the power to Mexico by the US might quickly end up in literal pieces.
posted by scruss at 11:37 AM on January 18, 2019

Oh yeah, they're easy to vandalize and ruin. Just throw rocks at them, as you say. Boom, string's down.
posted by Anticipation Of A New Lover's Arrival, The at 1:07 PM on January 18, 2019

Also, a solar farm is not a wall in any meaningful sense.

Most of the things I came in here to say have already been said. I want to reemphasize this one, though - you are proposing combining two things that are just not the same. We may as well try to turn the border into one long car factory to provide domestic jobs. Or one long hydroponic farm to provide lettuce in the winter. Also a 10-mile-wide stripe along the border is a WAY bigger undertaking than a couple hundred yards of wall and related support infrastructure. By, like, a factor of 10.
posted by Joey Buttafoucault at 9:14 PM on January 18, 2019