French wind propulsion firm AYRO — which is supplying Oceanwings sails to cut fuel use by up to 35% on a ro-ro vessel that will transport Ariane 6 rocket parts — is taking a flexible design route compared with its rigid sail rivals.

The company has developed polyvinyl chloride (PVC) material sails that can be furled and reefed in similar ways to traditional sails but provide the aerodynamic benefits of wings at a much lighter weight.