Download or read book A Remotely Operated Hydrokinetic Turbine to Reduce the Levelized Cost of Energy of Marine Turbines written by Armin Hamta and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel hydrokinetic turbine system is proposed to address key commercialization challenges facing the marine energy industry. Challenges include addressing icing issues by eliminating equipment that pierce the water/air interface; reducing the levelized cost of energy by simplifying demanding deployment and retrieval procedures; and positioning the turbine in the water column to maximize annual power production. Results of the experimental test matrix shows successful operation of the scaled counter-torque mechanism which operates with a 20 cm diameter rotor and is stabilized from the reactive nature of two point masses located at opposite ends of a spoke connected to the nacelle. Static and dynamic analytical modeling, computer aided design, manufacturing, and experimental testing of the prototype is the methodology that validates the operation of the counter-torquing mechanism. The prototype turbine is tested in a laboratory water tunnel at Reynolds numbers of 94 x 10^3, 104 x 10^3, and 115 x 10^3; with the generator loads ranging from free-wheeling to 6.2 W; and available counter-torque capacity varying from 0% to 40%. The maximum power coefficient obtained during the tests is 48.3% at a rotor tip speed ratio of 4.5. This research advances the Technology Readiness Level of the proposed novel turbine system from a level one to a level four based on the U.S. Department of Energy definition for technology development.

Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by M. Beam and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Designing Optimizing and Testing of a River Hydrokinetic Prototype Turbine System for Remote Northern Communities written by Raul Vaid and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A hydrokinetic turbine extracts energy from river currents and can enable communities worldwide to establish micro-grids to address part of their base loads. Hydrokinetic turbines offer a viable solution to produce power year-round to displace diesel generation in northern communities. However, these turbines must operate in reduced winter flows and not be impacted by ice. A passive-counter-torque and river-prototype hydrokinetic turbine integrated system is presented that offers a simpler and lower-cost approach to deploy, operate and maintain hydrokinetic turbines year-round in cold climates. A 500-W river prototype designed with a 0.48 m diameter two-blade impeller is optimized, built and tested. It produces a torque of 24.44 Nm at 200 RPM for a flow velocity of 2.0 m/s. For this in-situ prototype, shrouds, winglets, and wingtips are developed and optimized to reduce the levelized cost of electricity and micro-grid performance when flow velocities are lower than the design set point of 2.0 m/s. Such off-design conditions are mainly experienced during winter seasons. Numerical simulations confirm that the winglet design maintains the design power when experiencing up to 18% reduction in velocity. Various design combinations were tested by varying component dimensions: 2,216 combinations for shrouds and 4,103 for winglets. The optimal results were achieved using the shrouds, while the winglets were found to have the advantage to prevent stalling. Testing of the prototype turbine at the Canadian Hydrokinetic Turbine Testing Centre shows that the counter-torque design selected was stable. However, using a field vacuum pump to control the ballast in the configuration tested needs to be reconsidered.

Download or read book Marine hydrokinetic turbine power take off design for optimal performance and low impact on cost of energy written by M. Beam and published by . This book was released on 2013 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by and published by . This book was released on 2012 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 drive train, 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, low maintenance and cost with a low impact on the device Cost-of-Energy (CoE).

Download or read book Passive Pitch Control in Marine Hydrokinetic Turbine Blades written by Ramona Brockman Barber and published by . This book was released on 2014 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green and renewable energy technologies are becoming more and more necessary as demand for energy grows exponentially around the world. Recently, there has been increased interest in using marine hydrokinetic turbines to generate energy from ocean currents and tidal flows. The blades of these turbines are slender and are subjected to large, dynamic fluid forces; for that reason they are typically constructed from fiber-reinforced composites. The bend-twist deformation coupling behavior of these materials can be hydroelastically tailored such that the pitch angle of the blades will passively change to adapt to the surrounding flow, creating an instantaneous reaction that can improve system performance over the expected life of the turbine. Potential benefits of this passive control mechanism include increased lifetime power generation, reduced hydrodynamic instabilities, and improved load shedding and structural performance. There are practical concerns, however, that increase the complexity of the design of these bend-twist coupled blades. Large inflow variations in viable locations for turbine implementation combined with system component limitations such as restrictions on the generator and maximum rotational speed require consideration of practical and site-specific constraints. Using a previously validated boundary element method-finite element method solver, this work presents a numerical investigation into the capabilities of passive pitch adaptation under both instantaneous and long-term variable amplitude loading to better describe potential benefits while considering practical design and operational restrictions.

Download or read book Development of a Control Co Design Modeling Tool for Marine Hydrokinetic Turbines Preprint written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the ongoing and planned development of the software package CT-Opt (Current/Tidal Optimization), a control co-design modeling tool for marine hydrokinetic turbines. The commercialization of these turbines has faced significant challenges due to the complex, multidisciplinary nature of their design and the extreme environmental conditions of their operation. This project aims to create a modeling tool that will enable the efficient design of robust, cost-competitive hydrokinetic turbine systems. Rather than using traditional optimization methods, CT-Opt combines multiple models across a range of fidelities to enable coupled optimization of the system design and system controller via a control co-design approach. With this method, the parameters that affect system performance are considered more comprehensively at every stage of the design process. The lowest-fidelity, frequency-domain model called by CT-Opt is RAFT (Response Amplitudes of Floating Turbines), which was originally developed by the National Renewable Energy Laboratory (NREL) to model response amplitudes of floating offshore wind turbines. The highest-fidelity, time-domain model is OpenFAST, which was developed by NREL for land-based and offshore wind turbines. As part of the CT-Opt project, new functionalities will be added to RAFT and OpenFAST to enable the accurate simulation of fixed and floating marine hydrokinetic turbines. In addition to expanding the capabilities of RAFT and OpenFAST, new midfidelity models will be developed. These models will be based on RAFT and OpenFAST and will consist of linearized, state-space models derived from the fully coupled, nonlinear OpenFAST equations and derivative function surrogate models that approximate the nonlinear system behavior. Each model will be coupled with controllers to allow control co-design methods to be applied both within models and across fidelity levels, enabling efficient system optimization.

Download or read book Hydrokinetic Turbine Systems for Remote River Applications in Cold Climates written by John Woods and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In-situ testing of hydrokinetic river turbines demonstrates the feasibility of installing these turbines in cold climates and at remote communities without significant infrastructure requirements. Complete water-to-wire systems are deployed, tested in winter conditions and retrieved with major aspects of the technology investigated. A robust river-bottom anchoring system is developed and tested suitable for remote communities with minimal infrastructure. Vertical-axis 5-kW and 25-kW hydrokinetic turbines are deployed and tested in the Winnipeg River, under various climatic and flow conditions: -36oC to 30oC and 2.0 m/s to 2.6 m/s. Winter testing reveals that frazil ice accumulates on devices near the water surface, ice forms at the air-water interface, and ice sheets flowing with the stream can impact near-surface components. These factors lead to the conclusion that for low-maintenance and reliable year-round deployment in cold climates, systems must be fully submerged and removed if major ice floes occur. Hydrokinetic turbine generated power is delivered to a utility 12.47-kV overhead distribution line through pole-top transformers and bi-directional electricity meters, establishing a remote community water-to-wire system for the first time. Commercially available rectifier/inverters, developed for use in wind and solar energy capture, are successfully integrated into the power conversion system for the 5-kW and 25-kW units, reducing costs. A power conversion design is developed and tested. Concurrent measurement of river flow and turbulence with electrical power output from the permanent magnet generator are obtained in-situ. This data is used to investigate power production fluctuations resulting from turbulence in the flow. Turbulence is evaluated in detail, using time domain and frequency domain analysis. Calculated turbulence length scales varied from 0.7 m to 1.2 m, which are in the order of magnitude for the physical rotor elements. The results show that power extraction is maintained in the presence of moderate to high levels of turbulence in the range of 4% to 5% and that such level can improve energy capture. These studies indicate that hydrokinetic turbine systems can provide reliable power for both micro-grids and base-load applications in remote communities located in cold climates if placed below the water surface and not impacted by river ice floes.

Download or read book Analysis of Hydrokinetic Turbines in Open Channel Flows written by Arshiya Hoseyni Chime and published by . This book was released on 2013 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rivers and irrigation canals are good candidates to produce small-scale hydrokinetic power. Traditionally, gates are used to control water flow in such waterways by dissipating kinetic energy of the flow. This study investigates potential of replacing these gates with Horizontal Axis Hydrokinetic Turbines (HAHT). These machines are designed so that not only power can be extracted but also flow is going to be maintained at the required flow rate. This application increases renewable energy capacity and decreases energy dependency on foreign resources. In this study, theoretical and numerical approaches are used to model HAHT in open channel flows. Theoretical method uses one-dimensional control volume analysis to predict maximum power that an ideal rotor can extract from the flow as useful power and wake mixing at a given Froude number and blockage ratio. This method is then compared to three-dimensional Actuator Disc Model (ADM) developed in commercial Computational Fluid Dynamic (CFD) code ANSYS Fluent. This model uses a porous media to represent HAHT and Reynolds-Average Navier-Stokes (RANS) equations along with Volume of Fluid (VoF) model to solve for flow field and track the free surface. Same computation method is implemented with a more advanced model, Virtual Blade Model (VBM), which uses blade element theory to consider geometry of the blade and operating conditions such as angular velocity and pitching angle. This method is used to optimize the turbine geometry for maximum power and find operating limits to avoid cavitation. Previous literature mostly concentrates on performance of Horizontal Axis Tidal Turbines in channels where blockage ratio is low and consequently free-surface deflection is not a matter of interest. Even in cases where blockage was considered in order to validate flume experiments, velocity deficit of wake region was the main focus. However, this research attempts to fill the gap in literature for better understanding the power extraction of HAHT and subsequent head loss (flow control) in highly blocked flows using three methods mentioned above. In addition, this work attempts to use validated VBM to answer if one-dimensional theory and CFD ADM are capable of predicting power production of HAHTs in highly blocked and low head flows such as irrigation canals.

Download or read book An Evaluation of the U S Department of Energy s Marine and Hydrokinetic Resource Assessments written by National Research Council and published by National Academies Press. This book was released on 2013-04-23 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing renewable energy development, both within the United States and abroad, has rekindled interest in the potential for marine and hydrokinetic (MHK) resources to contribute to electricity generation. These resources derive from ocean tides, waves, and currents; temperature gradients in the ocean; and free-flowing rivers and streams. One measure of the interest in the possible use of these resources for electricity generation is the increasing number of permits that have been filed with the Federal Energy Regulatory Commission (FERC). As of December 2012, FERC had issued 4 licenses and 84 preliminary permits, up from virtually zero a decade ago. However, most of these permits are for developments along the Mississippi River, and the actual benefit realized from all MHK resources is extremely small. The first U.S. commercial gridconnected project, a tidal project in Maine with a capacity of less than 1 megawatt (MW), is currently delivering a fraction of that power to the grid and is due to be fully installed in 2013. As part of its assessment of MHK resources, DOE asked the National Research Council (NRC) to provide detailed evaluations. In response, the NRC formed the Committee on Marine Hydrokinetic Energy Technology Assessment. As directed in its statement of task (SOT), the committee first developed an interim report, released in June 2011, which focused on the wave and tidal resource assessments (Appendix B). The current report contains the committee's evaluation of all five of the DOE resource categories as well as the committee's comments on the overall MHK resource assessment process. This summary focuses on the committee's overarching findings and conclusions regarding a conceptual framework for developing the resource assessments, the aggregation of results into a single number, and the consistency across and coordination between the individual resource assessments. Critiques of the individual resource assessment, further discussion of the practical MHK resource base, and overarching conclusions and recommendations are explained in An Evaluation of the U.S. Department of Energy's Marine and Hydrokinetic Resource Assessment.

Download or read book Hydrokinetic Power written by Evan Mangold and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrokinetic energy, the power of moving water, is a promising new, vast, and renewable resource that is unhindered by many of the weaknesses experienced with other clean energy sources. The recent installation of a prototype hydrokinetic turbine at Yakima, WA's Roza Canal serves as an example of this, as the turbine produced over 5,000 kWh in one month, exceeding expectations. This thesis analyzes this turbine's performance while also looking at two canals in eastern Washington's Kittitas Reclamation District as potential sites for hydrokinetic turbines. The estimates demonstrate hydrokinetic turbines to not only be a clean, reliable, and continuous power source, but to also be a cost-effective investment in ideal sites.

Download or read book Numerical Modeling of the Effects of a Free Surface on the Operating Characteristics of Marine Hydrokinetic Turbines written by Samantha Jane Adamski and published by . This book was released on 2013 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine Hydrokinetic (MHK) turbines are a growing area of research in the renewable energy field because tidal currents are a highly predictable clean energy source. The presence of a free surface may influence the flow around the turbine and in the wake, critically affecting turbine performance and environmental effects through modification of the wake physical variables. The characteristic Froude number that control these processes is still a matter of controversy, with the channel depth, the turbine's hub depth, the blade tip depth and the turbine diameter as potential candidates for a length scale. We use a Reynolds Averaged Navier Stokes (RANS) simulation with a Blade Element Theory (BET) model of the turbine and with a Volume of Fluid model, which is used to track the free surface dynamics, to understand the physics of the wake-free surface interactions. Pressure and flow rate boundary conditions for a channel's inlet, outlet and air side have been tested in an effort to determine the optimum set of simulation conditions for MHK turbines in rivers or shallow estuaries. Stability and accuracy in terms of power extraction and kinetic and potential energy budgets are considered. The goal of this research is to determine, quantitatively in non-dimensional parameter space, the limit between negligible and significant free surface effects on MHK turbine analysis.

Download or read book Water Current Turbines written by Peter Garman and published by Intermediate Technology Publications. This book was released on 1986 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed from Intermediate Technology (now Practical Action) experience in Sudan, this handbook describes the development and testing of the water current turbine as a simple and inexpensive means of lifting water for irrigation purposes. With detailed technical information on the technology, this manual also includes an economic assessment of its cost-effectiveness compared with other pumping technologies. This book is designed for the use of engineers and development workers who may be interested in trying this technology

Download or read book Hydrokinetic and Marine Energy Technologies written by Progressive Management (Firm) and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Cost of Electricity written by Paul Breeze and published by Elsevier. This book was released on 2021-02-28 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cost of Electricity is an essential tool for any researcher or practitioner seeking to establish the economic and environmental cost of power generation, and thereby to analyse the economic feasibility of power systems. Chapters cover capital cost, fuel cost, levelised cost, subsidies and tariffs, lifetime emission analysis, net energy analysis, traditional generation costs and renewable generation costs. The work is based on published analyses of generation costs and generation cost predictions from trusted organisations such as the US Energy Information Administration and the IEA. Chapters proceed in a logical manner through cost factors before concluding with the current and future cost of electricity generation. - Analyses the factors that contribute to the cost of generating electricity together with the presentation of historical cost trends and predictions for future costs - Examines the environmental cost of power generation by lifecycle analysis, including carbon emissions impact - Reviews factors which distort the market cost of electricity

Download or read book Computational Fluid Dynamics Study of a Cross Flow Marine Hydrokinetic Turbine and the Combined Influence of Struts and Helical Blades Preprint written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational fluid dynamics study was performed for a cross-flow marine hydro-kinetic turbine. The analysis was done in three dimensions and used the unsteady Reynolds averaged Navier-Stokes solver in the commercial code STAR-CCM+. The base turbine configuration is the RivGen® Turbine, designed by the Ocean Renewable Power Company (ORPC). A convergence and uncertainty analysis was performed for both the spatial and temporal discretization; this was done using the base configuration which features support struts and helical foils. The proposed study aims to compare the impact of the struts on both power performance and blade loading for helical and straight blades.