Posted on December 24, 2020
The U.S. Department of Energy has awarded $21 million to three offshore wind technology demonstration projects, including a study to develop a large floating offshore wind platform.
Houston-based engineering consultancy Atkins will develop a full-scale design of a floating offshore wind platform capable of supporting a 10-plus megawatt class turbine, the economical size deployed in most offshore wind developments. The funding will support scale model testing and simulation using methods developed for oil and gas floating production facilities.
Over the years, Atkins has been involved in more than half a dozen floating wind projects, including WindFloat, Hywind, Kincardin and Hexicon. The DOE-backed research project is specifically aimed at installation and commercial grid connection at Shell’s Mayflower Wind lease area off the coast of Massachusetts.
Mayflower Wind is an as-yet-unpermitted project located about 30 miles to the south of Martha’s Vineyard, with wind potential for about 1.6 gigawatts of energy. The project’s backers – Shell and EPDR – have sold about half that capacity to Massachusetts utilities with a 20-year power purchase agreement, and they plan to bring it online by the mid-2020s. The initial development plan calls for bottom-fixed turbines and a bottom-fixed offshore substation.
The Mayflower Wind lease parcel lies in between similar lots acquired by Orsted, Vineyard Wind and Equinor. Like the adjacent lease areas, its southwestern segment has water depths exceeding 30 fathoms (180 feet) – over twice the depth at the Block Island Wind Farm site, and well over the typical 50 meter (165 foot) limit for an economical bottom-fixed wind farm.
Deep water is the ideal application for floating wind platforms, which adapt anchoring technology from the offshore oil and gas industry to the purpose of supporting turbines. Floating wind platforms have not yet been installed in a full-scale commercial wind farm, and though wind resources are often better at locations further offshore, the capital expense involved in manufacturing and deploying them is expected to make them a more expensive option (on a levelized cost of energy basis) for the foreseeable future.