Abstract: Wave energy convertor (WEC) 100 and related control methods. The WEC has at least one cell 102 of variable volume containing an energy transfer fluid and at least partially bounded by a movable flexible membrane 106, and the at least one cell has a substantially constant membrane pressure differential during at least part of a respective cell volume deflation or inflation stroke. Pressure differential between the exterior and interior surfaces of the membrane of the respective cell can be maintained as stable and constant as possible for a substantial part of the volume change during deflation and inflation of the membrane/cell. Membrane and/or cell inclination angle can range between 35° and 50°. Chord ratio of the flexible membrane of at least one cell can be between 1.01 and 1.3 during operation. A control surface 108 can modify the available membrane surface or limit of operation of the membrane for operation and/or modify an internal wall or surface of the cell.

Abstract: Wave energy convertor (WEC) 100 and related control methods. The WEC has at least one cell 102 of variable volume containing an energy transfer fluid and at least partially bounded by a movable flexible membrane 106, and the at least one cell has a substantially constant membrane pressure differential during at least part of a respective cell volume deflation or inflation stroke. Pressure differential between the exterior and interior surfaces of the membrane of the respective cell can be maintained as stable and constant as possible for a substantial part of the volume change during deflation and inflation of the membrane/cell. Membrane and/or cell inclination angle can range between 35° and 50°. Chord ratio of the flexible membrane of at least one cell can be between 1.01 and 1.3 during operation. A control surface 108 can modify the available membrane surface or limit of operation of the membrane for operation and/or modify an internal wall or surface of the cell.