> They are an attractive option for some military ships, but I doubt anyone would be willing to risk it for regular commercial shipping.

There's been a few built over the years, mostly for research.

Russia apparently still operates one.

https://en.wikipedia.org/wiki/Sevmorput

Despite hurtles you've pointed to it is still being considered:

https://www.spglobal.com/commodity-insights/en/news-research...

> This source of power confers some advantages. "You will have ships going maybe 50% faster because the fuel is essentially free once you have made the upfront capex investment," Sohmen-Pao said.

You achieve ~0 emissions AND avoid increasing transit time going with pure sailing ships.