MiniWEC works to maximize wave energy capture (Video)

 
Researchers from the University of Washington’s Applied Physics Laboratory (APL-UW) are conducting tests on a small wave energy converter test platform whose results could make a contribution to the greater marine renewable energy community.

The video below features descriptions of the MiniWEC test platform provided by APL-UW team which is researching the technology to provide scalable wave energy converter (WEC) models and adaptive computer controls to maximize energy capture.

The MiniWEC is a floating point absorber that uses the rotation of a spring loaded spindle to produce power. A heave plate is tethered to the spindle opposing the springs such that the motion of the waves causes the spindle to oscillate around the equilibrium point, according to APL-UW.

Rob Cavagnaro, Senior Engineer at APL-UW, said: “The relative motion between the float and the plate creates tension on a line that is able to ‘translate’ a generator. The generator consists of a bunch of coils that are being moved across a bar of permanent magnets that induces a current and creates electricity. So, it’s the force from the motion of two bodies that pulls the generator.

“Just based on the hydrodynamics of the two bodies, the system has some level of springiness and some resistance to motion. With the control system you can change those parameters actively, so you’re able to adjust how springy it is and how much energy you’re taking off.

“It’s set up so that it runs autonomously, so we give it the control parameters that we’d like to apply and we just let it run. It makes decisions based on the feedback from its various sensors – we’re measuring velocity, voltage, current and how the float is moving itself.

“All those pieces of information can be used to tune the system to get more energy out.”

The APL-UW team is working in collaboration with private companies which are developing similar wave energy devices.

Curtis Rusch, Ph.D. student at UW Mechanical Engineering, said: “We’re working with CalWave to look at various heave plate shapes. They’re interested in developing a better understanding of heave plates and their hydrodynamics in the interest of making a heave plate suitable to their wave energy converter.”

Rusch added the APL-UW team is also working with Seattle-based Oscilla Power to try and develop a better understanding of how well a model will work when you apply it to real world situations.

The MiniWEC has been tested in real conditions in the waters of Lake Washington, and Puget Sound.