Harnessing the Motion of the Ocean

Michael Bernitsas, an engineer from the University of Michigan, is making a splash with his new prototype for a machine that can harvest the power of the ocean’s waves.  The technology, known as the Vortex Induced Vibrations Aquatic Clean Energy (referred to as VIVACE for short), is able to harvest what energy experts consider to be a vastly untapped resource, ocean energy.  Bernitsas’ contraption is spawned by years of work trying to suppress wave energy for the oil industry.  According to Bernitsas, “about four years ago, it dawned on me that we should enhance the vibrations and try to harness the energy.”  So how does it all work?  When ocean currents flow over a cylinder it creates vortices that over time spin away and create energy.  The oil industry doesn’t like this, because this energy causes vibrations that can destroy the cylindrical moorings that hold up drilling platforms.

Bernitsas’ device mimics this phenomenon.  The prototype consists of evenly spaced round cylinders connected to springs that are submerged in water.  When the water moves, so do the cylinders, and VIVACE converts this mechanical energy into electricity (click here for video).  Hydrokinetic generators already exist, like the Pelamis Wave Power project off the coast of Portugal, but they depend on faster currents, around 6 knots, while most currents in the world’s oceans are somewhere around 3.  VIVACE is so promising because it is able to harness the energy of these slower currents.

While there are still many kinks to work out in the technology, recent trends hint at a sea change in the policy.  The Bailout was chock full of incentives for individuals and businesses to invest in clean energy, including ocean energy.  Also, both presidential candidates are ardent supporters of stimulating the green economy.  Don’t get too excited, though, it will take years, if not decades, for ocean energy to realize its full potential and Bernitsas admits “we’re where cars were 100 years ago.”  However predictions that ocean energy could provide up to 10% of US demand suggests that VIVACE may have a promising (and dare I say, lively) future.