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A Comparison of Platform Options for Deep-water Floating Offshore Vertical Axis Wind Turbines: An Initial Study

Bull, Diana L.; fowler, matthew f.; goupee, andrew g.

This analysis utilizes a 5 - MW VAWT topside design envelope created by Sandia National Laborator ies to compare floating platform options fo r each turbine in the design space. The platform designs are based on two existing designs, the OC3 Hywind spar - buoy and Principal Power's WindFloat semi - submersible. These designs are scaled using Froude - scaling relationships to determine an appropriately sized spar - buoy and semi - submersible design for each topside. Both the physical size of the required platform as well as mooring configurations are considered. Results are compared with a comparable 5 - MW HAWT in order to identify potential differences in the platform and mooring sizing between the VAWT and HAWT . The study shows that there is potential for cost savings due to reduced platform size requirements for the VAWT.

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Hydrodynamic module coupling in the offshore wind energy simulation (OWENS) toolkit

Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE

Fowler, Matthew J.; Goupee, Andrew J.; Owens, Brian; Hurtado, John; Alves, Marco; Bull, Diana L.; Griffith, Daniel G.

When considering the future of offshore wind energy, developing cost effective methods of harnessing the offshore wind resource represents a significant challenge which must be overcome to make offshore wind a viable option. As the majority of the capital investment in offshore wind is in the form of infrastructure and operation and maintenance costs, reducing these expenditures could greatly reduce the cost of energy (COE) for an offshore wind project. Sandia National Laboratory and its partners (TU Delft, University of Maine, Iowa State, and TPI Composites) believe that vertical axis wind turbines (VAWTs) offer multiple advantages over other rotor configurations considering this new COE breakdown. The unique arrangement of a VAWT allows the heavy generator and related components to be located at the base of the tower as opposed to the top, as is typical of a horizontal axis wind turbine (HAWT). This configuration lowers the topside CG which reduces the platform stability requirements, leading to smaller and cheaper platforms. Additionally this locates high maintenance systems close to the ocean surface thus increasing maintainability. To support this project and the general wind research community, the Offshore Wind ENergy Simulation (OWENS) toolkit is being developed in conjunction with Texas A&M as an open source, modular aero-elastic analysis code with the capability to analyze floating VAWTS. The OWENS toolkit aims to establish a robust and flexible finite element framework and VAWT mesh generation utility, coupled with a modular interface that allows users to integrate easily with existing codes, such as aerodynamic and hydrodynamic codes.

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Technological cost-reduction pathways for attenuator wave energy converters in the marine hydrokinetic environment

Bull, Diana L.

This report considers and prioritizes the primary potential technical costreduction pathways for offshore wave activated body attenuators designed for ocean resources. This report focuses on technical research and development costreduction pathways related to the device technology rather than environmental monitoring or permitting opportunities. Three sources of information were used to understand current cost drivers and develop a prioritized list of potential costreduction pathways: a literature review of technical work related to attenuators, a reference device compiled from literature sources, and a webinar with each of three industry device developers. Data from these information sources were aggregated and prioritized with respect to the potential impact on the lifetime levelized cost of energy, the potential for progress, the potential for success, and the confidence in success. Results indicate the five most promising costreduction pathways include advanced controls, an optimized structural design, improved power conversion, planned maintenance scheduling, and an optimized device profile.

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Results 76–95 of 95
Results 76–95 of 95