Design synthesis of oscillating water column wave energy converters: performance matching

The matching of a Wells air turbine to an oscillating water column (OWC) is addressed, with particular reference to design synthesis at the Islay prototype wave power converter. The level of damping applied by the turbine must optimize the hydraulic performance of the OWC in order to facilitate efficient conversion from wave power to pneumatic power. Furthermore, a Wells turbine is only able to convert pneumatic power to mechanical power over a limited range of flow coefficients. Therefore, the efficient operational range of the turbine must extend over a sufficient and optimal proportion of the range of flow coefficients generated by the OWC. Suitable analytical models that describe the behaviour of the system are presented and subsequently the wave conditions and conversion performance at the Islay plant are outlined in order to exemplify the design synthesis to be achieved.