This was originally something I looked at over the course of a few minutes and wanted to post on Twitter, but then realized there was no way I was going to make it fit. So here it is on the depository I created for the long-form version of my most boring-est thoughts.
A story broke earlier today that President Trump suggested adding solar panels to the border wall to help it pay for itself. In light of this and earlier accounting suggesting the price of the Border Wall as originally envisioned could be as high as US$66.9 billion, I was wondering how much electricity we could currently build in solar for that amount of money. As it turns out (assuming my math is correct), if we were talking about using that sum of money to build utility scale single axis tracking solar systems, we could potentially build enough solar capacity to generate about 10% of the total electricity consumption of the US.
My 30 second Excel spreadsheet completed with a Wikipedia source is below.
| Value | Unit | Source |
| 1.49 | $/Watt Solar Energy | http://www.nrel.gov/docs/fy16osti/66532.pdf |
| 66,900,000,000 | Dollars (66.9 Billion) | http://time.com/4745350/donald-trump-border-wall-cost-billions/ |
| 44,899,328,859 | Total Watts | 66.9 billion/$1.49 per Watt |
| 393,318,120,805
(393 billion) |
kWh/yr | (Total Watts/1000)*365*24 |
| 3,913,000,000,000
(3,913 billion) |
US Electricity Consumption (kWh/yr) | https://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption |
| 10.1% | % of Total US Electricity Consumption |
In fairness to myself, that Wikipedia article did do a good job of at least listing its source, the CIA World Factbook.
Now, would the wall provide sufficient surface area for all that wattage? Google tells me that solar panels generate 10-13 Watts per square foot. Based on my total wattage number above, 44899328859, this means we would need about 4489932885.9 square feet of area using the conservative 10 Watt/square foot number (see what I did there?). My favorite source also tells me that the US-Mexico border is 1954 miles (10117120 ft). That would make the border wall need to be over 400 feet wide to accommodate the proposed wattage at 10 watts per square foot.
This doesn’t really belong here, but here’s a picture I took of an ostrich to break up all the boring text.
Yeah, so none of this seems likely for a bunch of reasons. On top of the behemoth panel width, I’m guessing the proposed panels were probably fixed and not tracking, which brings down the efficiency, and the installation costs would be massive and likely in addition to the actual construction costs of the wall instead of displacing any of those costs. As for how you tie in 1954 miles of 400 foot wide solar panels into a distribution grid and how much you would lose in transmission losses tying all that in, I’m just going to say that’s outside my scope. Not even I like math that much.
Feel free to check my work and let me know what I messed up if you find anything.
P.S.-After posting, I realized the formatting of the Excel table is terrible. I’m not fixing it, I just wanted to make sure you knew that I knew that it is terrible, that’s all.
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