Green alternative for hydraulic system
The aim of the AQUAGEN (Development of cost-effective, water based power take-off system for marine energy applications) project was to create a more dependable, environmentally friendly PTO system. A consortium of small and medium-sized enterprises (SMEs), engineering consultants and researchers developed innovative components for the new PTO system. These include a variable-speed generator, an adaptive blade turbine, elastomeric structures and the overall hydraulic system, and new protective coatings for marine environments. Project partners also modelled the ageing elastomeric structures and developed wireless controlled monitoring of offshore equipment. AQUAGEN's main focus was the development an elastomeric PTO system and the prototype that was designed, built and tested. Researchers investigated criteria such as performance benefits, cost of manufacture, and operating and maintenance requirements. They found that the elastomeric pump unit exhibited lower maintenance requirements than conventional oil-hydraulic cylinders. This was due to the design (a rolling seal), which showed reduced stress and wear on sealing components compared to conventional piston-type seals. In addition, the working fluid (water) is incompressible and considerably cheaper than hydraulic oil. The combination of the rolling seal element and water as the working fluid have far greater tolerance to contamination and therefore require less filtration and specialised handling. Results from the AQUAGEN initiative will be integrated into the existing Poseidon P80 wave energy converter (WEC) platform, which is designed to operate in significantly deeper water than most existing WECs. The platform can be used for the direct pressurisation of water and fed into a reverse osmosis desalination plant to produce freshwater. It can also be used for hydrogen production and small-scale hydropower generation. AQUAGEN supports the EU's policy on renewable energy by enabling the conversion of wave energy into electricity around the coasts of Member States. Its outcomes will improve economic growth and quality of life throughout the EU by aiding job creation and the growth of SMEs, increasing energy security and producing drinking water in arid regions located near the sea.
Keywords
Power take-off, marine environment, energy applications, elastomeric structure, rolling seal
