Solar Panels, from Sea to Shining Sea?
President Trump has creatively suggested the United States place solar panels on his administration’s proposed southern border wall. Electricity generated from the wall, the theory goes, might recoup some of the wall’s construction and maintenance expenses. How feasible is this plan? What will a solar border wall cost? How much electricity can the wall generate? Let’s explore a few factors that will determine whether or not installing a wall of solar panels from sea to shining sea makes sense.
Cost of Panels
The average standard size residential solar panel is roughly 65 inches by 39 inches. The average commercial size panel is 77 inches by 39 inches. Utility scale or custom panels for the wall project might be larger, so using a 39 inch width is not exactly perfect. But, assuming a wall of 1,989 miles, this equals 10,501,920 feet, or 126,023,040 inches of typical residential sized panels. That translates to 3,231,360 39 inch wide panels for either a five foot wall covered in panels or one row of continuously fixed tilt panels on top of a higher wall. A ten foot wall fully covered in panels would require 6,462,720 panels. This is a rough estimate based on current average solar panels. Custom designed panels would change the equation.
What might all these panels cost? The current rock bottom price for utility scale solar is about $1 per watt, with costs ranging from $0.99 per watt to $1.08 per watt. Those Costco-priced panels are likely made in China. As an all of the above American energy jobs leader, President Trump should not settle for less than American manufactured solar panels. This translates to $2.00-$2.50 per watt. Any company bidding to create the world’s largest solar installation, as this project would undoubtedly be, may be able to employ economies of scale that reduce the American-made panel cost. For purposes of this analysis, a $2.00 per watt price will be assumed to stay on safe side. After all, for security and durability purposes, these southern border panels will be more expensive than this, because the panels need to be constructed of high-grade materials that can be easily repaired or replaced in the likely event vandalism.
These average panels will have generation capacities of 250 to 300 watts. At 250 watts at $2 a watt for beautiful, U.S. manufactured solar panels, that’s $1,615,680,000 for a five foot wall or $3,231,360,000 for a ten foot wall. President Trump has, at times, even proposed a 40 or 50 foot wall. In that case, the U.S. will need to buy many more panels to cover the entire wall with vertical panels. These costs are rough estimates for the panels only. The estimates do not include installation, maintenance, custom design fees for the project or other expenses related to underlying wall construction.
Other analysts have attempted rough estimates for the cost of a great solar wall. A Politico Morning Energy analysis found the U.S. will, “need 4,364,434 panels from Home Depot to run the entire 1,989 miles of the proposed border wall.” At $125 a panel, the cost of a modest panel from Home Depot.com, that would run a cool $545,554,250 for the panels. Gleason Partners, a Nevada company, has already submitted a bid to the federal government to build a concrete wall with solar panels. Gleason Partners bid a price of $6 million dollars a mile for the wall with panels, or $11,934,000,000 for a 1,989 mile wall. An analysis by Financial Times columnist Bryce Elder suggests $3 billion for 10 million panels to convert the southern border wall into an electric tour de force. Gordon Johnson at Axiom Capital Management estimates the U.S. will need to acquire 13,358,136 solar panels to cover 1300 miles of a 40 foot tall wall, at a whopping cost of $7.6 billion.
In practical reality, tapping the solar power potential of a southern border wall will not mean installing panels on every last inch of the wall. Even if the U.S. does seek to maximize panel placement on the wall, spacing and alignment issues for the panels also mean the wall will likely need fewer panels than any of these estimates. And, it is far more probable the wall will feature smaller installations of solar panels with storage systems at various points along the wall to meet the electricity needs of both the wall (i.e. flood lights) and border security forces at key checkpoints.
How much electricity?
A wall comprised of 6,462,720 250 watt solar panels will have a generation capacity of approximately 1.61 gigawatts. In context, one gigawatt of solar can power approximately 750,000 average homes. The Politico Morning Energy rough analysis finds the Home Depot solar panels it uses as a benchmark would have, “1.25 gigawatts of total capacity.” Gleason Partners states their wall will have a generation capacity of two megawatts an hour, and Johnson’s analysis for a mega-solar wall pegs a 4.7 gigawatt capacity. There is a rub, however. An average solar panel typically operates at only 20 percent efficiency, although it is closer to 40%-50% efficiency in high sun exposure areas like the southwest. What all of this means is the actual amount of electricity generated on a regular basis will be 50%-80% less than the wall’s capacity.
Wall Geography and Electricity Delivery
The U.S.-Mexico border is certainly sunny territory, but much of the terrain is rough and remote. The costs of maintenance, security and grid interconnection for solar panels in difficult to reach areas must be considered versus the costs of a wall without the need for solar panel maintenance and grid interconnection. If the wall proposes to generate a serious electricity supply for the people, long distance, high voltage transmission lines will be necessary, as much of the southern border is not in close proximity to the existing U.S. electric grid. One estimate based on a 2012 study places a starting price tag on such a transmission line project at $8.5 billion.
Of course, this assumes an ambitious, large-scale solar wall project. If instead, the solar panels were only on small sections of the wall, combined with storage, and designed to offset electricity costs related to wall operation or other border control installations, it could potentially save taxpayer dollars in reduced electricity costs over the life of the wall. This could also improve the energy security of the wall. For example, smaller combined solar and storage installations may make it easier to power lights and operations on remote areas of the wall that cannot easily be connected to the existing electric grid.
Can the Great Solar Wall Pay for Itself?
Whether or not a grand southern border solar installation can pay for itself through electricity sales is difficult to predict in the absence of clear, specific proposals and construction plans. Gleason Partners, which proposed a wall of concrete and solar panels, estimates its proposed wall will pay for itself within five years. Another analysis of a generic wall by Axiom Capital Management’s Gordon Johnson is less optimistic. Johnson estimates the great solar wall will cost $27.6 billion to construct and will generate $221 million per year in profit, meaning it will take over a century for the entire wall plus solar panels to pay for itself. The solar panels themselves, however, represent only $7.6 billion of Johnson’s cost estimate for the wall. The panels could theoretically pay for themselves much more quickly than the entire underlying wall construction.
Putting solar panels on the southern border wall might make sense at some places on the wall, especially from a security and back-up power perspective for remote areas of the wall. A bigger, 1,989 mile wall length solar plant, on the other hand, will be quite expensive, increase security costs for the wall and necessitate the building of expensive transmission infrastructure if the wall-generated electricity is to be deliverable to U.S. households. The President and the American people need to carefully evaluate specific proposals for solar wall construction and then determine if the potentially premium costs will be worth the benefits of a significant source of zero variable cost electricity generation, improved energy security and job creation.