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The U.S. marine energy industry is actively pursuing development of offshore wind and marine hydrokinetic (MHK) energy systems. Experience in the wind energy sector demonstrates that new technology development requires thorough measurement and characterization of the environmental conditions prevalent at installation sites and of technology operating in the field. Presently, there are no turn-key instrumentation system solutions that meet the measurement needs of the marine energy industry. The 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop brought together technical experts from government laboratories, academia, and industry representatives from marine energy, wind, offshore oil and gas, and instrumentation developers to present and discuss the instrumentation needs of the marine energy industry. The goals of the meeting were to: (1) Share the latest relevant knowledge among technical experts; (2) Review relevant state-of-the-art field measurement technologies and methods; (3) Review lessons learned from recent field deployments; (4) Identify synergies across different industries; (5) Identify gaps between existing and needed instrumentation capabilities; (6) Understand who are the leading experts; (7) Provide a forum where stakeholders from the marine energy industry could provide substantive input in the development of new marine energy field deployable instrumentation packages.

Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a power-take-off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drivetrain, power generator, and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost, and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency and low maintenance and cost, with a low impact on the device cost-of-energy (CoE).

This report provides an overview of developments and considerations regarding wave, tidal, and in-stream energy generation technology. It summarizes federal involvement in the regulation of this new industry and highlights current issues in the field.

Ocean current energy represents a vast untapped source of renewable energy that exists on the outer continental shelf areas of the 5 major continents. Ocean currents are unidirectional in nature and are perpetuated by thermal and salinity sea gradients, as well as coriolis forces imparted from the earth's rotation. This report details THORs Power Method, a breakthrough power control method that can provide dramatic increases to the capacity factor over and above existing marine hydrokinetic (MHK) devices employed in the extraction of energy from ocean currents. THORs Power Method represents a constant speed, variable depth operational method that continually locates the ocean current turbine at a depth at which the rated power of the generator is routinely achieved. Variable depth operation is achieved by using various vertical force effectors, including ballast tanks for variable weight, a hydrodynamic wing for variable lift or down force and drag flaps for variable vehicle drag forces.

This fact sheet explains how the Marin Solar Program (MSP) conducted market analysis and created a solar potential map on a small budget.

Polycrstalline diamond (PCD) bearings were designed, fabricated and tested for marine-hydro-kinetic (MHK) application. Bearing efficiency and life were evaluated using the US Synthetic bearing test facility. Three iterations of design, build and test were conducted to arrive at the best bearing design. In addition life testing that simulated the starting and stopping and the loading of real MHK applications were performed. Results showed polycrystalline diamond bearings are well suited for MHK applications and that diamond bearing technology is TRL4 ready. Based on life tests results bearing life is estimated to be at least 11.5 years. A calculation method for evaluating the performance of diamond bearings of round geometry was also investigated and developed. Finally, as part of this effort test bearings were supplied free of charge to the University of Alaska for further evaluation. The University of Alaska test program will subject the diamond bearings to sediment laden lubricating fluid.

The ocean-energy industry is still in its infancy and device developers have provided their own equipment and procedures for testing. Currently, no testing standards exist for ocean energy devices in the United States. Furthermore, as prototype devices move from the test tank to in-water testing, the logistical challenges and costs grow exponentially. Development of a common instrumentation package that can be moved from device to device is one means of reducing testing costs and providing normalized data to the industry as a whole. As a first step, the U.S. National Renewable Energy Laboratory (NREL) has initiated an effort to develop an instrumentation package to provide a tool to allow common measurements across various ocean energy devices. The effort is summarized in this paper. First, we present the current status of ocean energy devices. We then review the experiences of the wind industry in its development of the instrumentation package and discuss how they can be applied in the ocean environment. Next, the challenges that will be addressed in the development of the ocean instrumentation package are discussed. For example, the instrument package must be highly adaptable to fit a large array of devices but still conduct common measurements. Finally, some possible system configurations are outlined followed by input from the industry regarding its measurement needs, lessons learned from prior testing, and other ideas.

This report describes wave, tidal, and in-stream energy generation technologies -- also referred to as hydrokinetic or marine energy. It discusses the recent changes in law aimed to clarify the federal role in ocean wave and renewable energy.

This fact sheet describes the federal incentives available as of April 2013 for the development of water power technologies.

AbstractThis paper describes a recent study to investigate the applicability of a horizontal-axis wind turbine structural dynamics and unsteady aerodynamics analysis program (FAST and AeroDyn, respectively) for modeling the forces on marine hydrokinetic turbines. This paper summarizes the added mass model that has been added to AeroDyn. The added mass model only includes flow acceleration perpendicular to the rotor disc and ignores added mass forces caused by blade deflection. A model of the National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI wind turbine was analyzed using FAST and AeroDyn with seawater conditions and the new added mass model. The results of this analysis exhibited a 3.6% change in thrust for a rapid pitch case and a slight change in amplitude and phase of thrust for a case with 30° of yaw.