This project investigated the effects of biofouling on a wave energy converter using an open loop seawater power take-off system.
We worked with Queen’s University Belfast to research replacing freshwater with seawater as the hydraulic fluid in the power-take-off system. Using freshwater means that if a leak occurs the system has to be flushed out and refilled. This can be expensive and time-consuming.
Using seawater would mean that the system can be refilled from surrounding seawater and leaks become less important. However, potential micro and macro biofouling by organisms from bacterial to invertebrate scale become an important consideration when utilising seawater.
The literature study results suggest that due to the complex nature of biofouling and the number of factors it depends on, it is difficult to accurately predict the effects without site-specific testing. However, components of the wave energy converter system most likely to experience effects were identified. They were the inlet screen, the low-pressure pipeline and the discharge tank. The high-pressure pipeline, the pump/ram and the turbine were considered to be less susceptible due to the faster flow of fluid through them.
The outcomes of this study are feeding into our developing plans for a programme of environment-focussed research, in which biofouling communities and anti-fouling measures are key work streams.
Improvements to anti-fouling measures could reduce operational and maintenance costs, making devices more cost-effective, improving their availability and providing real benefits to the industry.