Saw this article over on the solarpunk subreddit and wanted to bring it over here with my own opinion attached.
For being a near-zero way to travel in the air it's solar, but the reasons the author criticizes solar-electric propelled airships make it punk. The issues pointed out by the author - slow travel time, lower passenger counts, and windows of time for viable travel, a need for sleepers - could also be seen as its strengths.
For one, slow travel time and lower passenger counts make it a lot easier to meet and connect with strangers with little social risk. They also wouldn't need sleepers. With tight spaces like that, they're less comfortable than economy. My wife and I took a long distance train here in the U.S. (which has its own issues), but we loved the social interaction and actually preferred our economy seats over the sleepers. Two years later, we still like to chat about some of the folks we met and speculate on how they're doing.
The long transit time and specific travel windows would force people to rethink how badly they actually wanted to travel overseas and consider a more local scope. If that's not solarpunk...
The discussion below the original article mentions "Caspian Sea Monster" - which uses "ground effect", but there are more modern versions that are not monsters - for example this electric sea-glider might be promising for coastal trips ?