Seafloor carpet mimics muddy seabed to harness wave power
By Nick Lavars
February 23, 2014
Many organizations around the world are looking at ways to harness the power of waves as a renewable energy source, but none are covering quite the same ground as a team of engineers from the University of California (UC), Berkeley. The seafloor carpet, a system inspired by the wave absorbing abilities of a muddy seabed, has taken exploring the potential of wave power to some intriguing new depths.
Muddy seabeds have long been known to absorb the impact of ocean waves. When a severe storm strikes in the Gulf of Mexico, local fisherman make for areas where they know the ocean floor to be heavily laden with mud, as the softer sub-surface takes the sting out of the waves and provides respite from the storm and violently surging seas.
Drawing inspiration from this, the UC team set about devising a system where the energy would not only be absorbed, but converted to usable energy.
A rubber mat forms the "carpet," which while sitting atop a grid of hydraulic actuators, cylinders and pumps, takes on the motion of the incoming waves. In moving up and down, the carpet creates hydraulic pressure in the cylinders, which is then piped back to shore to be converted to usable power.
Experiments conducted at UC Berkeley have shown that the carpet is capable of absorbing more than 90 percent of the wave's energy. According to the researchers, one square meter (10.8 sq ft) of seafloor carpet would generate enough electricity to power two US households, while 100 square meters (1080 sq ft) of carpet would provide the same power as a soccer field covered in solar panels (6,400 square meters or 68,889 sq ft).
“We plan to start testing this system in the ocean within the next two years, and we hope to have it ready for commercial use within the next 10 years,” said Assistant Professor of Mechanical Engineering at UC Berkeley, Reza Alam.
The team emphasizes the durability and versatility as strengths of the system. As it is seabed-based, made from flexible non-corrosive materials and intended to be installed in shallow coastal water about 60 ft (18 m) deep, it should be able to "survive the strong momentum of the stormy seas." The team says the system can be easily transported and its modular design allows it to be scaled up or down in width, depending on environmental and energy demands.
In addition to offering an alternate source of energy, the conversion process produces seawater at high pressure, which can be used for desalination and distributing fresh water, a potential boon for residents in coastal regions prone to drought.
Having tested experimental setups in the Berkelely laboratory, the team has turned to Experiment, a crowdfunding site for research projects, to drive the next phase of the endeavor. If their goal is reached, the team will develop a larger prototype to test performance and identify materials for real ocean applications.
You can hear from Alam and other brains behind the project in the video below.