Not so easy.
I did a deep dive into the container ship industry many years ago in order to understand unit economics and how certain technologies could improve the ecologic impact of this massive industry. It was very interesting. I learned a lot.
I see a lot of comments about going electric, hydrogen, solar, sail, some kind of hybrid, etc. I don't think any of this is near any time horizon I can name or recognize.
Why?
Cargo ships use something called "Bunker Fuel" [0].
What is bunker fuel?
Well, to put it simply, it is what's left after you take petroleum and distill it into various grades of gasoline, diesel, industrial oils, etc. It is often referred to as "the bottom of the barrel". Another way to think of it is that bunker fuel is the waste product. Some grades of bunker fuel are so thick you can walk on it and will only flow if heated. This should not come as surprise, asphalt is the next level down and that stuff is solid enough to make roads out of it.
Why did I say "not so easy"?
Because these ships are effectively burning the waste product from the manufacturing process that leads to all the fuels and lubricants we consume in massive quantities.
What does this mean?
If we stopped using bunker fuel next Monday, what would we do with the absolutely massive amounts of bunker fuel produced every year? Think about that for a moment.
Sure, hydrogen and electric sound "clean", but you would have a potentially larger ecologic disaster in having to dump bunker fuel somewhere. The bottom of the barrel isn't going to magically disappear just because we transition cargo ships to something else.
What to do then? It's a tough problem. One solution, maybe, I don't know, is to evaluate how efficiently and cleanly we might be able to burn bunker fuel on land vs. on a ship. My point is that we might be able to extract and use this energy in a super-clean way, to charge batteries or whatever. I haven't studied this at all. I would imagine that if we set out to truly create a super-clean process to burn bunker fuel on land for energy generation it could be a good path forward. I don't know how much better we could do on land (in terms of clean burning) than on a ship. I'd like to think we could do a lot better.
I do think the future is electric, in some form. What I can't see or predict is how we transition from today's reality to that reality. This isn't a case of just having to solve the containership problem, you have to solve the entire oil/fuel ecosystem because, if you don't, you are going to have astronomic amounts of bunker fuel (waste product) to contend with. This is how shifting cargo ships to electric could actually be worse for the environment than letting it be and working to make them as clean as possible. Weird, isn't it?
[0] https://en.wikipedia.org/wiki/Fuel_oil
