Making current with currents
Ocean currents never stop flowing. They’re a ceaseless source of energy—if you can harness them. They’re too slow to spin turbines and the ocean tends to wreak havoc on steel and concrete. A team of engineers led by professor Michael Bernitsas at the University of Michigan, however, have discovered a way nab the energy in ocean currents despite these problems.
Their new system, called VIVACE (Vortex Induced Vibrations Aquatic Clean Energy), exploits vibrations that can tear man-made structures apart.
It all has to do with Aeolian Tones. Originally described by Leonardo da Vinci, they’re the ghostly resonating sounds that strings or cables can emit when air passes over them. The vibrations that make those sounds are caused by vortices pushing the cable back and forth. These vibrations can be extremely violent, as seen in the infamous film of the Tacoma Narrows bridge oscillating itself to bits. Engineers typically try to avoid these vibrations when building structures, but Bernitsas is using them in VIVACE. Slow-moving ocean currents crete vortices that are strong enough to push steel tubes up and down, and generate power.
The system is currently being tested and could be ready for deployment in the near future. Bernitsas estimates that the ocean currents could generate enough power for the entire world. His company, Vortex Hydro Energy, plans to have systems on the market soon.
