The book The Windup Girl is maybe only adjacent to solarpunk, but it features the return of sail ships along with some similar changes.

It seems like a smart option to consider for slower cargo runs: humans used to cross the ocean frequently with no fuel - with the reliability and safety of modern shipbuilding designs, radio communications, and engines when they need them, it seems like it could be safe and practical (less fast and reliable but without externalizing the cost of those benefits)

Edit: also, it reminds me of waterworld, and that’s cool