I understand that, in fact probably uniquely to people on this thread I've been on a rotor sail boat (not sailing though, in dock).
They do work when the ratio of the sail area to the boat is appropriate. In the case of the one I went on it was a very efficient hull too - very light weight catamaran.
The ships in the article you link have huge sails on reasonably small ships. The ones suggested by Norsepower are absolutely tiny compared to the ship. They are, like i've said, about the same cross sectional area of a small pleasure sailing yacht on huge container ships.
They do work when the ratio of the sail area to the boat is appropriate. In the case of the one I went on it was a very efficient hull too - very light weight catamaran.
The ships in the article you link have huge sails on reasonably small ships. The ones suggested by Norsepower are absolutely tiny compared to the ship. They are, like i've said, about the same cross sectional area of a small pleasure sailing yacht on huge container ships.