Comprehensive Shared-Mooring Solutions to Minimize the Cost, Risk, and Footprint of GW-Scale Floating Wind Farms
Alliance for Sustainable Energy, LLC
Recipient
Golden, CO
Recipient Location
$1,081,893
Amount Spent
Active
Project Status
Project Update
The team completed the project design basis, which defines the assumptions to be used when developing mooring system designs throughout the project. The design basis includes site-specific wind, wave and current data, technical design requirements such as safety factors, a variety of regional design considerations, and the project's baseline floating wind turbine design. This baseline design consists of the IEA Wind 15-MW reference turbine, two semisubmersible platform options, and a taut polyester-rope mooring system. The baseline design was simulated for key load cases and its OpenFAST input files are available on GitHub.
Next, the team developed a four-stage methodology for designing shared mooring systems for large floating wind farms. The first stage is a linear two-dimensional layout design that is used for rapid, initial design screening. The second stage uses three-dimensional quasi-static models to size individual mooring components. The third and fourth stages use more sophisticated models (the frequency-domain model RAFT and the time-domain model FAST.Farm) to further evaluate and refine the designs, with feedback loops to earlier design stages to balance efficiency and accuracy.
The team applied the first two stages to explore a variety of shared mooring system conceptual design options including shared mooring lines, shared anchors, and hybrid shared configurations. A full 1-GW floating wind farm design was generated for each mooring concept, including the layout within the lease area, initial component sizing, and cost estimates. In parallel, the team identified key stakeholders for design feedback, installation logistical requirements for different mooring configurations, and the marine mammals and environmental impacts that warrant the most consideration. These efforts are leading to weightings and metrics that will be factored into design decisions. After the conceptual design options are compared according to these metrics, the top concepts will be selected for advancement to more detailed design stages.
The Issue
Floating wind farms rely on mooring lines and anchors to keep each wind turbine in position and limit their horizontal motions so that power cables are not strained. In the deep waters found off California, conventional mooring approaches face challenges. Longer mooring lines are required to reach the seabed, increasing the material use, cost, and footprint of the mooring systems. The space needed for each mooring line can cause difficulties in maintaining adequate clearances around mooring lines and power cables. Seismic activity in the region poses a further challenge by increasing the risk of anchors failing. These challenges call for mooring solutions that are more cost-efficient, compact, and resilient to component failures.
Project Innovation
This project will develop comprehensive shared mooring system solutions that minimize the costs, failure risks, and environmental impacts of GW-scale floating wind farms in California site conditions. The approach combines state-of-the-art techniques for sharing mooring lines and anchors with installation and maintenance innovations that bring additional cost reductions and reliability improvements. Strategic use of shared mooring lines will make the designs especially resilient to anchor failures, which will be critical to the viability of large-scale floating wind farms in California.
Project Goals
Project Benefits
The project will lower electricity costs and improve electricity reliability. These benefits are the result of the project’s support for the feasibility, cost reduction, and risk reduction of floating offshore wind farms in California
Key Project Members
Matthew Hall
Subrecipients
Texas A&M University
University of Iowa
Cal Poly Humboldt Sponsored Programs Foundation
H.T. Harvey and Associates
Principle Power
American Bureau of Shipping
Delmar Systems, Inc.
Match Partners
Texas A&
M University
University of Iowa
H.T. Harvey and Associates
Schatz Energy Research Center
Principle Power
American Bureau of Shipping
Delmar Systems, Inc.
