West coast floating offshore wind, pluses and minuses

A floating wind array in operation off the coast of Portugal.
A floating wind array in operation off the coast of Portugal.
A floating wind array in operation off the coast of Portugal.

As the offshore wind industry begins to blossom in the U.S., companies are eager to be part of the action even though questions still linger about the viability of meeting the federal government’s ambitious green energy goals.

The “single most important factor” to future development of the technology is government support, according to the Global Wind Energy Council.

The Biden-Harris administration is leveraging historic amounts of resources from its ‘Investing in America’ agenda to bring the nation’s first major offshore wind projects online. The administration’s goal is the deployment of a staggering 30 gigawatts (Gw) of offshore wind energy capacity by 2030.

Currently, the federal Investment Tax Credit provides a 30 percent credit for offshore wind projects that begin development before 2026, a potentially critical advantage for the U.S. market. 

So far, almost all of the offshore wind energy projects approved by the administration are located along the U.S. East Coast as the continental shelf extends far into the Atlantic allowing offshore wind turbines to be planted like massive redwoods directly into the seabed on a firm foundation in water up to 165 feet deep. 

About two-thirds of U.S. offshore wind energy potential exists over waters too deep for today’s fixed-bottom wind turbine foundations secured directly to the sea floor, and instead require floating platforms, these structures will be among the largest humankind has ever constructed. 

Such is the case along the U.S. West Coast, where the continental shelf drops off rapidly so turbines cannot be erected close to shore. 

Rather, offshore wind turbines would have to be positioned on floating structures anchored to the seabed with mooring lines.

The first ocean areas leased for potential West Coast offshore wind development are in federal waters adjacent to California. These areas were identified by the Bureau of Ocean Energy Management (BOEM) and auctioned in December of 2022 with project developers spending more than $750 million to gain site control.

In preparation for the development of offshore wind there, officials at the Port of Long Beach have released plans for Pier Wind, which when completed would be the largest facility at any U.S. port designed to accommodate the assembly of offshore wind turbines.

Port of Long Beach Executive Director Mario Cordero said no other location on the Coast “has the space to achieve the economics of scale” to drive down the cost of energy for the turbines, which will stand as tall as the Eiffel Tower.

“As society transitions to clean energy, our harbor is ideally located for such an enterprise – with calm seas behind a federal breakwater, one of the deepest and widest channels in the U.S., direct access to the open ocean, and no air height restrictions,” he said. 

“Imagine fully assembled wind turbines capable of generating 20 megawatts of energy towed by sea from the Port of Long Beach to offshore wind farms in Central and Northern California.” 

The $4.7 billion project involves construction of a 400-acre facility located in the Harbor District just southwest of the recently completed Long Beach International Gateway Bridge, the span which links Long Beach proper with the port’s massive cargo-handling facilities on adjacent Terminal Island. 

Officials at the BOEM have announced plans to hold a lease auction for floating wind energy sites off the Oregon coast. The two Draft Wind Energy Areas are located between 18 and 32 miles off the coast, and cover an area of more than 219,560 acres.

The four possible configurations for floating offshore wind power generators.
The four possible configurations for floating offshore wind power generators.

Overall, the goal of installing offshore wind infrastructure along the West Coast is a massive undertaking that’s not without its challenges – floating offshore wind farms require a more complex support network and, as a result, are more expensive to construct. 

In addition, greater wind speeds resulting in greater blade wear, strong seas, accessibility issues, the need for complex infrastructure support, and the construction of more specialized vessels combine to make the path to the development of floating offshore wind farms a challenging strategy to bring to fruition with an associated cost predicted to reach some $11 billion. 

Last year, floating offshore wind and its potential development spawned a growing number of reports, studies, and analyses of developing any one, or a combination, of the four types of floating wind platforms – spar-buoy, tension leg platform, semi-submersible, and barge.

According to a recent report compiled by the National Renewable Energy Laboratory, the generation of 55 Gw of energy along the entire West Coast by 2045 could require the construction of nine staging and integration sites at four to five ports and 17 operations and maintenance sites in Oregon, Washington state, and California, which is taking a particularly keen interest in floating offshore wind technology. 

“Floating offshore wind is the most suitable technology” to harness offshore wind energy along the California coast due to the depths of the waters, according to California State Lands Commission, citing that the Morro Bay Wind Energy Area has a development capacity of 3 Gw, while the Humboldt Bay Wind Energy Area can support 1.6 Gw. Both areas have wind speeds averaging around 20 mph, or approximately 9 m/s.

To address the concerns accompanying the development of floating offshore wind, the West Coast Offshore Wind Transmission Literature Review and Gaps Analysis project was launched in 2022 with funding from the U.S. Department of Energy’s Wind Energy Technologies Office (WETO).

The project supports the activities of the Floating Offshore Wind Shot (FOWS), a federal interagency program which aims at reducing the cost of producing floating offshore wind energy by 70 percent by 2035. 

“Investments in floating offshore wind energy will help usher in America’s clean energy future by tapping into 2.8 terawatts of potential power – more than double the current U.S. electricity consumption,” according to a joint statement from the group, which is composed of representative teams from the U.S. Departments of Energy, Transportation, Commerce, and Interior. 

Over the span of several months, the Washington-based Pacific Northwest National Laboratory reviewed a number of studies that examined the feasability of developing floating offshore wind projects along the U.S. West Coast.

Among them was an analysis published in May 2023 that was co-written by wind energy experts from the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy and found that the points of interconnection for the West Coast, particularly in key regions with robust wind resources, “are limited in number and onshore transmission capacities for integrating offshore wind power with the grid are not clear.” 

Work on the PNNL renewable energy research study was headed by Travis Douville, a professional engineer with extensive experience in the offshore wind sector.

The paper analyzed the options available to support floating offshore wind development through 2050. 

Developing offshore wind energy, Douville said, “needs to begin on land. The wind industry needs near-term targeted land-based infrastructure upgrades and technologies to prepare the existing grid for offshore power flows.”