By Ramona Cornell du Houx
March 14, 2025
As electricity use rises to power transportation, buildings, AI, and more, researchers estimate that the western United States will need 400 additional gigawatts (GW) of generation capacity by 2050.
A January 2025 report shows that floating offshore wind could bring 33 GW of energy to the western United States by 2050 and bolster the resilience of coastal communities. And in some scenarios, the additional transmission that would be built to transport the offshore wind could also help to transport lower-cost energy like solar and hydropower, ultimately leading to billions of dollars in savings across the Western Interconnection.
The Department of Energy’s (DOE’s) Pacific Northwest National Laboratory and National Renewable Energy Laboratory spent the last two years studying the costs and benefits of adding floating offshore wind turbines along the United States’ Pacific coast.
Offshore wind energy in deep waters off the coast blows with force day and night. Access to offshore wind energy could improve grid resilience in coastal communities. Cities along the coast are far from where energy is generated by other sources, such as hydropower dams, solar panels, land-based wind turbines, and natural gas generators.
The research team scanned the entire West Coast for possible sites to place offshore wind turbines, but one area stood out in terms of wind strength and consistency. Between 10 and 50 miles off the coast of northern California and southern Oregon sits a 9,265-square-mile region of ocean where wind speeds average about 22 miles per hour.
“We found that approximately 30 GW of offshore wind energy and transmission components could be deployed in economically favorable locations off central and northern California and southern Oregon,” said Greg Brinkman, NREL coauthor on the study.
The researchers made sure to minimize or completely avoid overlap with parts of the ocean that are protected or used by other groups, such as the Coast Guard or Tribal communities.
“Building offshore wind comprehensively on the West Coast requires understanding which communities have the potential to benefit and where there are trade-offs between different transmission options,” said Katie Arkema, a coauthor on the report who studies the intersection of human and natural systems at PNNL. “Before anything can be built, we need to figure out how to deliver benefits from offshore wind to the communities that need them.”
Floating wind also offers some flexibility when it comes to operations and maintenance once a project is completed. “Repairs of fixed-bottom turbines must occur at site, but floating turbines can be towed to port, where maintenance can be carried out in a protected harbor,” the report said.
Developing that port infrastructure will be costly, the researchers said. The development of one port site could take up to 10 years and cost $1 billion. The report cites a 2023 study that found deploying 55 GW of offshore wind energy on the West Coast by 2045 would necessitate nine staging and integration sites — four or five ports — and 17 operations and maintenance sites, which would require an investment of around $11 billion.
“One of the main challenges is that port and grid infrastructure required for this level of offshore wind deployment does not exist along the West coast today,” the report said.
Researchers identified that by adding 13 GW offshore California and 2 GW offshore Oregon by 2035, and increasing that to 25 GW offshore California, 6 GW offshore Oregon and 2 GW offshore Washington by 2050 as the least-cost scenario.
Adding that capacity would help the Western U.S. reach the 400 GW of new generation the region is estimated to need by that year, and assist with the deployment of other generation by bolstering a transmission buildout, according to the report.