Marine Renewable Energy Laboratory

The MRELab is dedicated to developing technology to harness the abundant, clean, and renewable marine energy in an environmentally sustainable way and at a competitive cost. The current focus of the MRELab is to study the underlying science of the VIVACE Converter, which was invented in the MRELab (one patent granted, two patents pending) to harness the hydrokinetic energy of ocean/river currents/tides.

Marine Renewable Energy: Water is the largest and natural medium for energy storage. If we could harness just 0.1% of the ocean energy we would be able to cover the energy needs of 15 billion people. Of the solar energy available to Earth, 285 ZJoule/year are absorbed in water, 6 ZJoule/year are theoretically available in wind, and 1.8 ZJoule/year are absorbed in biomass. Worldwide energy consumption is less than 0.5ZJ. Marine renewable energy comes in five forms: currents, waves, tides, thermal gradient, and salinity gradient.

Sustainable Energy Harnessing: The primary challenge the World faces today is generation of renewable energy in an environmentally sustainable way at a competitive cost. Dams create major environmental problems. Turbines require an average of 5-7knots to be financially viable, while the vast majority of currents flow at speeds of less than 3knots. Concerns have also been raised regarding impact of turbines on marine life. VIVACE utilizes Flow Induced Motions (primarily Vortex Induced Vibrations and galloping), which are natural instability phenomena, and further enhances them using passive turbulence control and fish biomimetics.

The VIVACE Converter: VIVACE (Vortex Induced Vibration for Aquatic Clean Energy) is designed to: enhance rather than spoil vortex shedding; maximize rather than suppress VIV; harness rather than mitigate VIV energy. In 2005, the concept was model-tested in the Low Turbulence Free Surface Water Channel (LTFSWChannel) of the Marine Renewable Energy Lab. VIVACE takes the naturally catastrophic FIM's and successfully transforms them into a means of tapping into a virtually untapped energy source: the hydrokinetic energy of currents with speeds even less than 2knots. VIVACE is equally effective at high speeds as VIV is highly scalable. VIVACE is environmentally compatible technology estimated to generate energy at $0.055 -$0.10/kWh at maturity.

Facilities: Model testing is performed in the LTFSWChannel and the Towing Tank. Simulations are based on CFD and calibration. Model parameters include: Reynolds Number Re [8x103 -1.5x105], mass ratio m* [1.0 -3.14], current velocity U [0.35 m/s -1.15 m/s, aspect ratio L/D [6-36], mass-damping m*zeta [0.14-0.26], and spring stiffness. Four design parameters for Passive Turbulence Control via surface roughness and three fish-tail parameters complete the current matrix of parametric tests.

Education: Since the inception of MRELab in the summer of 2005, over 50 students have worked or are working in the lab at all degree levels: 10 PhD's; 1 PE; 2 MBA's; 5 MEng's; 5 MSE's; and over 20 undergraduates. Students study marine hydrodynamics, designing and conducting experiments, boundary layers, vortex induced vibration, galloping, laser visualization, energy harnessing, power take off, system integration, passive turbulence control, fish-biomimetics, marine renewable energy, environmental impact of energy harnessing, tech-transfer off an innovative idea, patenting process.

Research: PhD and publication activities focus on the following topics: (1) Enhancement of high damping VIV and galloping for energy harnessing, (2) expansion of the TrSL3 regime of high lift, (3) optimal FIM damping for energy harnessing, (4) electromagnetic power take off, (5) high damping VIV hysteresis, (6) passive turbulence control for FIM enhancement. (7) fish-biomimetics for energy harnessing, (8) CFD and calibration of cylinder flows in VIV, (9) flow past cylinder arrays, (10) energy phenomenological modeling, (11) VIV under nonlinear spring restoring force.


Director, Michael M. Bernitsas, Ph.D., Prof. of NA&ME, University of Michigan

Ph: (734) 764-9317; Cell: (734) 223-4223; Fax: (734) 936-8820;

Also: CEO and CTO Vortex Hydro Energy;