Published on July 1st, 2015 | by Tina Casey16
Biomimicry Wave Energy Device Ready To Leave The Nest
July 1st, 2015 by Tina Casey
A new bio-inspired method of harvesting energy from the ocean has completed its shakedown on land, and now it’s finally ready for its first real test offshore. Called bioWAVE, the wave energy device won’t be venturing too far — Port Fairy in Australia is as far as it’s going — but we can hardly contain our excitement because we’ve been waiting 7 years for this moment.
A Bio-Inspired Wave Energy Device
BioWAVE first crossed CleanTechnica’s radar back in 2008, when we compared the new wave energy concept to kelp.
That might seem a little imaginative considering what the device actually looks like:
However, kelp is pretty much on the money in terms of biomimicry. The BioWAVE wave energy device was inspired by the way that kelp sways and pivots with the movement of ocean swell waves.
The bioWAVE actually gives you a twofer of potential and kinetic wave energy harvesting.
It consists of an array of floats that rise and fall with the up-and-down surface motion of swells, which accounts for the potential energy. The kinetic energy comes in under the surface, as the floats (or “blades”) sway back and forth.
The prototype pictured above is a 250 kilowatt model designed for operation at 30 meters, as a midway step to developing a one-megawatt commercial version for 40–45 meter depths. The eventual goal is to have entire farms of bioWAVE devices — like beds of kelp — linked together.
From bioWAVE To Electricity
The tricky part is converting all that motion into electricity. The company behind the wave energy device, BioPower Systems (what else?), developed an on-board power conversion system it calls O-Drive.
As illustrated by the schematic at the top of this article, O-Drive is based on a high-pressure hydraulic fluid system, in which fluid is stored in a bank of accumulators. The accumulators literally accumulate the herky-jerky energy of the wave motion and release it in a steady stream to a hydraulic motor. The motor goes to a generator, and the generator cranks electricity into an undersea cable for transmission to the shore.
To pare down maintenance costs, BioPower has designed the O-Drive converter as a detachable module that can be hauled ashore for servicing.
As for inclement weather, when extreme seas threaten to damage the equipment, the bioWAVE floats are designed to collapse automatically onto the safety of the sea floor.
To get a feel for what’s going to happen when the device is deployed later this year, you can catch the bioWAVE in action on Vimeo.
Whither Wave Energy?
One key advantage of wave devices is their relatively low profile above the surface, and in the case of bioWAVE, no profile at all. That provides much more flexibility for site selection than offshore wind turbines, which can easily run into aesthetic obstacles.
In any case, the Australian government has faith. The bioWAVE project is partly supported by the Australian Renewable Energy Agency (ARENA) and the government of Victoria.
This is a big year for ARENA, which is also behind the unique Perth wave energy project that launched in March.
Here in the US, wave energy is also getting a huge lift from us taxpayers in the form of a public-private shared test bed at Marine Corps Base Hawaii and funding from the Energy Department so group hug.