INTELLECTUAL MERIT: The modern world needs a diverse energy portfolio and during the past decade, significant investments have been committed to harnessing marine renewable energy sources which have a theoretical potential to far exceed the world's present power generation needs. Of these untapped resources, open ocean currents, or predominantly unidirectional large scale circulations located near eastern coastlines of most continents, are located in deeper ocean areas (>250m), but flow near the sea surface. Various commercial interests now propose to install turbines to convert these vast kinetic energy reserves into usable electrical power, but thus far no large-scale commercial production prototypes have been constructed or tested in relevant environments. Perceiving the value these resources and to nurture their commercial development, the U.S. Department of Energy has designated three national centers to investigate solutions that help accelerate the pace at which marine renewables deliver base-load power to the grid and to provide testing capacities for evolving technologies. One such center, the Southeast National Renewable Energy Center (SNMREC) at Florida Atlantic University (FAU), is specifically tasked with enabling commercialization of open ocean current technologies.
A partnership between the SNMREC, the School of Naval Architecture and Marine Engineering at the University of New Orleans (UNO) and the Center for Energy Harvesting Materials and Systems (CEHMS) at Virginia Polytechnic Institute and State University (VT) has been organized to leverage the strengths of each institution to achieve the goal of helping the emerging ocean current energy industry overcome specific technical hurdles to promote and enable eventual commercialization. Future farms of ocean current turbines (OCTs) will be strategically located in the most energy dense portions of ocean current flows (near the surface, but anchored in deep ocean areas) to maximize power generation. To achieve positioning stability and to maximize generated power, OCTs are expected to efficiently avoid the wakes of nearby turbines and destructive environmental forces, but seek high energy density and consistent flow. Thus, these turbines must achieve autonomous and integrated electromechanical and position control. Unfortunately, because early commercial turbine design efforts are still focused on energy conversion demonstrations, small-scale validation, and hardware suitability for the operational environment, no significant effort has yet been applied to develop joint motion control for farms of OCTs, especially when coupled with power generation considerations. This effort therefore proposes to develop autonomous electromechanical and flight control systems to maximize the generated electricity by a single OCT unit, and then test effectiveness with a physics-based numerical simulation. Control optimization will involve active OCT rotor blade pitch angle control by leveraging helicopter flight control and modern multivariable constrained control techniques. The solutions will then be extrapolated to a farm of OCTs, which will require novel advanced collaborative control methodologies and will be validated with physics-based numerical simulation.
BROADER IMPACTS: For OCT concepts to become commercially viable, motion control and power generation optimization systems are needed. This project will achieve this requirement, will advance turbine modeling science, and will advance modern control design. This effort will directly enable the commercialization of ocean current energy conversion and will bring focus upon a new control and optimization application which will inspire significant innovation beyond this work. Major findings from this project will be directly integrated with the SNMREC, UNO and VT active outreach and education development programs which regularly share research outcomes with the public through presentations, workshops, the web, and conferences. A K-12 STEM enhancement curriculum and trained teachers in culturally diverse school districts will further benefit from this work. The university partners have also developed cooperative laboratory tools planned for direct incorporation into undergraduate curriculum. UNO, VT and FAU promote dissemination of applicable research data, helping prepare a future professional workforce toward a robust marine renewable energy sector.
