Oscillating water column (OWC) wave energy converters (WECs) have a well-proven feasibility, reliability and survivability when compared to many other wave energy converters. A good example for this is the LIMPET OWC plant, which has generated electricity to the grid for more than 60,000 hours in a period of 10 years. OWCs are quite successful when compare to other types of wave energy converters, including their simplicity and reliability in structure, their reliability and survivability in power take-off and conversion, and their adaptability in installation on shoreline, shallow water or deep water regions, but so far the wave power generation is still quite expensive. To reduce the cost of OWC wave power generation, one important aspect is how to design an efficient OWC device from the aspects of hydrodynamics and primary energy conversion.
This paper presents an investigation to the relation between wave energy conversion efficiency of OWC devices and the water column, including the column sectional area (column size) and water column length (column length). An analytical analysis/deduction has shown that in order to convert wave energy efficiently and with a high conversion efficiency, the column size and column length must be designed appropriately. Generally, a larger column size may be helpful in capturing more wave energy based on the mathematical equation and the relevant experimental validation. For an OWC device, a larger column size may also mean a higher conversion efficiency.
