Panama Canal Backgrounder

And some thoughts on fusion.

The Panama Canal is in the news thanks to Trump blustering without any fact checking. I’m familiar enough with the parameters that I can write about them.

This video is a pretty good backgrounder on the Panal Canal itself, as well as a couple of alternatives in the region. I started mentioning drought and shipping impact with Change Partners and it came up again in We’re Gonna Fight: International Edition.

While it is using machine voice, I think an actual human wrote the script used. I detected no hair raising mistakes while listening to it.

Desalination:

The Panama canal is under stress due to water usage. Their historic peak was about 36 ships a day and it takes roughly 160 acre feet per ship for a total of about 2.1 million acre feet of water per year. Putting that in perspective, the Mississippi averages 429 million acre feet per year; it’s not a lot of water, just 5,760 acre feet per day.

An acre foot is equal to 1233 cubic meters, so the flow is 7.1 million cubic meters per day, or a bit less than 300,000 cubic meters per hour. Estimates on desalination energy requirements are between one kilowatt hour per cubic meter and three kilowatt hours. Using the higher number, that’s 900 megawatts of continuous power use, which would power about 450,000 American homes. Put another way, the six reactors at Fukushima had outputs of 460MW (#1), 784MW(#2 - #5), and one 1100MW (#6) unit. A single current nuclear plant design could provide the needed desalination.

The water has to be lifted 26 meters from the ocean to Gatun Lake. I did some gymnastics and came up with an estimate of just over 21 megawatts per hour. The brine produced will need to be further processed, either by drying it completely for salt production, or simply using a tanker to dump it at sea. The fresh water that produced the brine will be returned to the ocean, so this will not result in the sort of problem the Persian Gulf has. Older desalination plants there are struggling, as they’ve made the sea to salty for them to produce.

Erring on the side of caution, what will a two gigawatts fusion reactor of the type first mentioned in Humanities Hope: Helion cost? It must be competitive with other generation methods and nuclear costs are around $31/MWH. Operating a two gigawatt plant would cost $62,000/hour, or $543 million per year. The canal brings the Panamanian government ten times that much revenue annually.

These are very broad strokes that took me an hour to produce. Assuming Helion works as planned, using the highest generating cost, and assuming the current relatively poor efficiency membrane desalination systems , this plan is quite plausible, even if my estimates are off by a factor of two.

Additional Benefits:

If one is already constructing a reactor, it could be made just a bit bigger to cover the fuel cost of the train line running parallel to the canal. The canal is constrained to Panamax sized ships. Not only would this save the fuel cost, it would duplicate the Mexican rail route that is already under construction.

I have not spent much time on the associated port facilities for the canal, but the video mentions large ships are running light to get through. They plan to offload some containers, railroad them to the other side, and then reload. Once you’re taking cans off a 400,000 ton Chinamax ship, you’re in a place to break the load down to several smaller ships on the far side. Breaking down large numbers of containers this way may provide added efficiency and flexibility to the system.

Hydrogen & Ammonia

Once we have a working fusion plant it can produce hydrogen by electrolyzing water. The fusion reactor will need about a liter of deuterium per every 18 megawatt hours. Deuterium is double the atomic weight of plain hydrogen and it’s about one out of every 5,000 atoms. The separation is accomplished by fractional distillation, getting the hydrogen progressively colder, with the deuterium condensing out before the hydrogen.

If you’re already built a fractional distillation setup, there may be a way to using the same facility to collect nitrogen. Once you’ve got hydrogen and nitrogen, a simple, albeit very hot Haber-Bosch reactor can be used to produce ammonia. This is humanity’s most common industrial chemical, with 90% going into fertilizer, with the rest going to make adhesives, explosives, fabrics, and so forth.

Conclusion:

If you ever stopped to read Gamma Draconis Rising you’ll know I have a pretty jaundiced view of the future for our species. If we don’t start treating climate change like the existential threat that it is, we’re going to cross various points of no return. Remediation has been the underlying motivation in most of what I’ve done since 2007, and I very much fear that we’ve already broken things that can never be mended.

If what Helion is doing truly works, we might just wiggle through what is sure to be a bottleneck for our species.