Donald Trump has created some buzz with discussing the potential for making the Mexico border wall a power plant: covering it with solar panels.
Amid Team Trump’s “Energy Week” (with nary a mention of wind or solar power, the fastest growing energy sources around the globe … and in the United States), a question to consider: how many coal-fired power plants would a solar wall displace?
First, to be clear, only the roughest of estimates can occur. The ‘solar wall’ is only notional at this time — while there is some analysis, there are no actual plans in place to evaluate fully. Rough estimates and initial calculations range from, if solar were across the entire length, are pretty far across the spectrum: from 3.6 terrawatt hours (tWh) per year to a(n unrealistically optimistic) high-end of over 80 tWh.
How does this compare to a coal power plant? A reasonable notional modern US coal plant is 600 megawatts of capacity. Running 24/7, that would mean 14,400 megawatt hours per day (14.4 gigawatt hours) or 5,256,000 per year (5,256 gigawatt hours or 5.256 twh). Now, power plants are — by definition — intermittent (despite all the ‘baseload’ noise) and do not run 24/7/365. In 2016, the average US coal power plant had a 52.7% utilization rate. Thus, this notional coal plant would generate 2,769,912 megawatt hours per year (2,770 gWh) or 2.7 tWh.
If an average coal plant produces 2.7 tWh, making the wall solar would displace the electricity production of somewhere between 1.3 to 22 coal power plants (with the actual figure likely somewhere in the 5-10 figure).
The reality is that, to date, solar has played a very small role in the decline of US coal (though the story is somewhat different elsewhere in the world: for example, in India, solar price competitiveness is leading to dramatic reductions in plans to exploit coal). In the US, the move away from coal has primarily occurred due to the drastic reduction in natural gas prices. Cheap gas has killed not-so-cheap coal. Now, with every passing day, solar is becoming more cost competitive with it achieving ‘cheapest’ in new markets virtually every month. Thus, if cheap natural gas killed off coal-fired power plants, what should be expected of even-cheaper solar?
Would making the ‘wall’ solar accelerate that ‘ever-cheaper’ and accelerate the (US and global) transition away from coal?
Thus, the impact of the solar wall on coal would not be constrained to those direct electrons but how the product, through driving economies of scale, would make solar even more price competitive even faster.
Notes: Some material re the solar wall includes:
- Powering America from Trump’s solar wall: how many kilowatts?
- Financial Times’ calculus puts this at 3.6 tWh/year.
- Jigar Shah: One Way to Get Mexico to Pay for Donald Trump’s Wall
- Business Insider
- The Motley Fool: Trump, Solar, and The Wall: What It Means for Solar Stock Investors