Researchers say 60-buoy array could capture 90% of wave energy in simulations
Simulations show 60 connected buoys could convert 90% of potential wave energy, but field tests are needed.
The proposed buoys would sit like flat drums on the water surface and connect to spring and generator units on the seabed. Each buoy would be individually tuned to match a particular wave rhythm, its resonance frequency, where the maximum amount of power can be produced. Professor Malte Peter of the University of Augsburg compared the principle to a child on a swing. “Only if the support comes at the right moment will the child swing higher and higher over time,” he said, in comments rendered by Google Translate. “Similarly, the waves must arrive at the buoy at the appropriate intervals so that its pendulum motion is as strong as possible.”
Ocean waves are difficult to capture because they are unpredictable. A large wave may hit a buoy that is already rising from a previous wave, causing much of its energy to be missed. Neighboring buoys can also deflect waves and affect one another’s movement. The larger arrays proposed by the team are intended to work as a sieve system: if one buoy misses a wave, another buoy that is better tuned to it can catch it, leaving little energy lost. The researchers describe careful adjustments to buoy positions and resonance frequencies to achieve the simulated result.
The idea builds on earlier work by some of the same researchers, who had developed a more basic two-dimensional model of a buoy farm. In the new paper, they extended the model into three dimensions, increased the size of the array and adapted it to a greater variety of wave directions. The design is meant to handle different types of waves rather than relying on a single fixed condition.
Despite the simulation results, the system remains theoretical. The team noted that each individual buoy could power “several hundred households” within the system, but installing and maintaining the equipment would be expensive. Field tests and further research are needed before the approach can be assessed as a practical source of renewable power, TechRadar reported.