AWS-III MULTI-CELL WAVE POWER GENERATOR
MULTI-CELL WAVE POWER GENERATION
The AWS-III is a multi-cell array of flexible membrane absorbers which covert wave power to pneumatic power through compression of air within each cell. The cells are inter-connected, thus allowing interchange of air between cells in anti-phase. Turbine-generator sets are provided to convert the pneumatic power to electricity.
A typical device will comprise an array of 9 cells, each measuring around 16m wide by 8m deep, arranged around a catamaran structure. Such a device is capable of producing an average of 2.4 MW from a rough sea whilst having a structural steel weight of less than 3500 tonne. The AWS-III will be slack moored in water depths of around 100m using standard mooring spreads.
The AWS-III has a number of significant advantages for utility-scale offshore wave-power. The flexible absorbers are highly efficient and are the only moving part of the power-train exposed to the sea. The use of air as a transmission medium removes end-stop issues whilst the air turbines employed are reliable proven technology. The large hulls provide a stable and safe working environment to allow on-board maintenance of the turbines, generators and all ancillary systems to ensure high reliability. Transformers and switchgear are adequately housed on-board and again easily accessed for maintenance. The diaphragms are designed with maintenance in mind using a patented ‘cassette’ system to allow change-out at sea.
AWS Ocean Energy has completed a rigorous programme of tank testing to establish the performance and survival conditions for the AWS-III, allowing us to complete a full FEED study for a prototype device. A half-scale cassette was built, deployed and tested at sea during 2014 and the technology is now ready to progress to full prototype stage.