Surprisingly, no. Last time this was posted there were some efficiency figures, wingsails being the best, but Flettner rotors still beating old-fashion sails an

Surprisingly, no. Last time this was posted there were some efficiency figures, wingsails being the best, but Flettner rotors still beating old-fashion sails and kites. And rotors are very likely cheaper than a sail/kite long term (they need complete replacement quite often because of rips and tears).