- 20k square meters of hull space
- If fully covered with solar panels, on a sunny day, you could expect 1-2 MWh (when averaging in night time)
- Current diesel engines typically output 60MWh continuously while underway.
And that's not factoring in the solar panels getting covered in salt over time and losing efficiency. Plus preventing the ship from actually loading / unloading cargo efficiently.
It's not just a matter of panel efficiency either. If we had magic panels that could absorb 100% of the suns power over the 20k sqm deck, it would only equate to about four times as much (8% of the overall power need).
- Solar: 1–2 MW of average power; ~24–48 MWh of energy per day.
- Diesel: about 60 MW of mechanical power while underway; ~1,440 MWh of energy per day.
60 MWh per what? Per hour? thats just 60 MW continuous POWER or 1440 MWh ENERGY per day.
There's more than enough lithium out there, more discovered every month, and the perception that we are limited by lithium is mostly out there because certain media sources are trying to help out there fossil fuel friends by delaying the energy interchange by a few years.
Whether battery ocean shipping containers make technical sense is a different question, but I wouldn't worry about lithium use!
Lithium, rare earth metals, and a bunch of others are only "scarce" because right now China is the only country willing to put up with the pollution levels that the cheap, dirty version of their extraction produces.
Everything can be produced cleanly, safely, etc... but that comes at a price.
It's like when employers complain that "nobody wants to work". That needs to be translated to "nobody wants to work for the low wages I'm willing to pay".
If there is demand for batteries in ships, it is going to be far smaller than for cars, which is currently 80% of battery demand (the rest is mostly grid storage). So ship batteries will at most slow the fall of battery pricing by a small amount.
Honestly DJI and Boeing should get into this business. A boat's sail basically a plane's wing, aerodynamically speaking. They share a lot of similarities with endurance gliders.
Try to approximate the area needed to generate e.g. 50MW propulsion. It would be measured in hectares.
I’m too lazy to do it myself but 5 minutes of searching and calculating will show you that the area of solar panels required to move a ship is far, far, larger than the area of that ship.
Not to mention that a container ship’s deck is typically completely covered with, well, containers.
Also, lithium isn’t scarce.
I guess in theory that could be solved either with huge removable panels around the containers (to be "put aside" somewhere during the loading operations), or placing containers with solar panels (and ways to deliver the energy to the ship) on the outer sides of the cargo.
Actually, maybe the batteries themselves could be loaded as containers on the sides of the cargo, with solar panels on them; that might increase the risk for the cargo if some catch fire, though
But, I guess it wouldn't be worthwhile.
Besides PV, there's a long history of wind powered ships of course.
I wouldn't underestimate what creative and dedicated engineers can accomplish.