Wave energy is regarded as one of the best sources of alternative energy, however, for the moment it cannot be considered as the most important as it’s very hard to harness water’s energy as the currents are not very strong. This obstacle hasn’t stopped researchers to try and find a way to generate energy from the natural motion of water, and an engineer from the University of Michigan has developed a hydrokinetic generator which uses ocean’s slow-moving currents to produce energy.

The hydrokinetic generator needs ocean’s natural “reflex” to produce energy as small vortexes are created when currents flow over a cylinder. This motion causes vibrations which means that there is a lot of energy waiting to be harnessed.

“About four years ago, it dawned on me that we should enhance the vibrations and try to harness the energy. No one has ever thought of patenting this idea, even though vortex induced vibrations were first observed in 1504 by Leonardo da Vinci,” said engineer Michael Bernitsas.

Bernitsas decided to commercialize his idea so he founded a company called Vortex Hydro Energy. Although there were many projects proposed to harness wave energy, only a few were put into practice like the Pelamis Wave Project located off the coast of Portugal, a system which generates only 2 megawatts of power. The problem is that wave turbines need fast-moving currents at over six knots, but the strongest currents move with less than three knots. However, Bernitsas’ technology requires only slow-moving currents so this won’t be a problem.

“There is a huge amount of hydrokinetic energy in currents but a lot of that we cannot harness with the present technology and that’s where my device comes in, to extract energy at speeds down to 1 knot. It taps into a new energy source,” said Bernitsas.

As the idea sounded very promising, Bernitsas managed to attract “investors” like the National Science Foundation, the U.S. Navy, and the Department of Energy who all raised $2 million for the development of the hydrokinetic generator. Bernitsas developed a prototype and called it the Vortex Induced Vibrations Aquatic Clean Energy.

The VIVACE system consists of cylinders measuring a few inches, and when the water flows past them, it creates vortexes which cause the cylinders to move up and down. Eventually, the system will convert the mechanical energy coming from these vortexes into electricity using rotary or linear generators. Although this project is only at the beginning, Bernitsas is very confident that in the future he will develop modular 50-kilowatt devices that will be used in power plants to generate a total of one gigawatt of power.

The VIVACE system will have to feature only state-of-the-art techniques to generate energy so that it would be very efficient, and Bernitsas was inspired by fish, wales, and other underwater creatures, which all use wave energy in a very efficient way.

“The muscle power the fish have is not enough to support the speed at which they are going. So, if you study more carefully, there are lots of things going on. A fish will curve its body, collect a vortex, shed it, and collect one on the other side and shed that, alternating on the two sides of its body,” said the engineer.

According to Bernitsas, his hydrokinetic generator will produce 50 watts per cubic meter of water at three knots currents, and you should be aware that the Pelamis system in Portugal produces only 21 watts per cubic meter of water. Although this looks very promising, there are lots of wave energy experts who do not believe in the success of the VIVACE system.

“I think that it’s at a very, very early stage of development,” stated Roger Bedard, analyst at the Electric Power Research Institute in Palo Alto, California.

Another downside of Bernitsas’ project is that he has “to go through 20 to 25 different regulatory agencies in this country,” meaning that you have to ensure the Government that the system is safe, doesn’t have technical issues, and that the wildlife will not be affected. Once again Bernitsas claims that the VIVACE system is more eco-friendly than any other systems.

“We’re where cars were 100 years ago. Hopefully it won’t take us 100 years to get where we need to be,” said the engineer. In conclusion, Bernitas said that a ready-to-use prototype will be deployed in the Detroit River in one year, but it could take less than this depending on the regulatory issues.