As a teenager growing up in Huntington Beach, CA – the original “Surf City” (yes, the town even trademarked the Surf City USA name!) – the sound of someone shouting “surf’s up” was our rallying cry! One of our greatest thrills was seeing Corky Carroll win the U.S. Surfing Championship at the Huntington Beach pier in 1969. Some of you may have seen it "live" back then on ABC’s Wide World of Sports, but we were there!
Now some Scottish and Italian engineers have added a new meaning to the expression “surf’s up”. Giacomo Moretti, Gastone Pietro Rosati Papini, Luca Daniele, David Forehand, David Ingram, Rocco Vertechy, and Marco Fontana, researchers at the University of Edinburgh and the Italian Universities of Trento, Bologna, and Scuola Superiore Sant’Anna Pisa, have published the results of their wave energy converter, based on dielectric elastomer generators (DEC-based WEC) in the Proceedings of the Royal Society A. For those not familiar with that publication, it is the Society’s mathematical, physical, and engineering sciences research journal. The Royal Society, itself, has an impressive history, having been founded in 1660 to promote the principles envisioned by Sir Francis Bacon.
The prototype DEC-based WEC has flexible rubber membranes on top of a vertical tube that is placed in the ocean. The wave motion causes the tube to partially fill with sea water, and it rises and falls as a result of the wave action. As the waves pass the tube, the water inside the tube pushes the air trapped in the top of the tube to inflate and deflate the membranes (DEC), which generates electricity. Of course, it’s obviously a bit more complicated than that, so my apologies to the researchers for my simplistic explanation. (You can read their complete paper here.)
When tested in the University of Edinburgh’s FloWave Ocean Energy Research Facility’s wave tank – "a circular 2 m-deep basin with a diameter of 25 m, circumferentially ringed by 168 absorbing wave makers" – the device produced peak power of up to 3.8W. According to the researchers, at commercial scale that would equate to several hundred kW (500kW could economically power 100 homes in coastal areas).
Granted, the waves off the coast of the barrier island in South Florida, where I now live, are not nearly as impressive as those in Huntington Beach. So it’s not often that we hear the cry of “surf’s up” here. But I would be certainly excited to hear “power’s on” when the waves break, regardless of their shape!
BONUS: For more on Corky Carroll, here's a vintage video from 1973:
A regular contributor to HPAC Engineering and a member of its editorial advisory board, the author is a principal at Sustainable Performance Solutions LLC, a south Florida-based engineering firm focusing on energy and sustainability.