ENERGY SECURITYOffshore Wind Farms Connected By an Underwater Power Grid for Transmission Could Revolutionize How the East Coast Gets Its Electricity
Offshore winds have the potential to supply coastlines with massive, consistent flows of clean electricity. One study estimates wind farms just offshore could meet 11 times the projected global electricity demand in 2040. In the U.S., the East Coast is an ideal location to capture this power.
Offshore winds have the potential to supply coastlines with massive, consistent flows of clean electricity. One study estimates wind farms just offshore could meet 11 times the projected global electricity demand in 2040.
In the U.S., the East Coast is an ideal location to capture this power, but there’s a problem: getting electricity from ocean wind farms to the cities and towns that need it.
While everyone wants reliable electricity in their homes and businesses, few support the construction of the transmission lines necessary to get it there. This has always been a problem, both in the U.S. and internationally, but it is becoming an even bigger challenge as countries speed toward net-zero carbon energy systems that will use more electricity.
The U.S. Department of Energy and 10 states in the Northeast States Collaborative on Interregional Transmission are working on a potentially transformative solution: plans for an offshore electric power grid.
At the core of this grid would be backbone transmission lines off the East Coast, from North Carolina to Maine, where dozens of offshore wind projects are already in the pipeline.
The plans envision it supporting at least 85 gigawatts of offshore wind power by 2050 – close to the U.S. goal of 110 GW of installed wind power by mid-century, enough to power 40 million homes and up from 0.2 GW today. The Northeast States Collaborative formalized their goals in July 2024 through a multistate memorandum of understanding.
Emerging research from the Department of Energy, the research company Brattle and other groups suggests that an offshore electric power grid could mitigate key challenges to building new transmission lines on land and reduce the costs of offshore wind power.
Cutting costs would be welcome news – offshore wind project costs rose as much as 50% from 2021 to 2023. While some of the underlying causes have subsided, such as inflation and global supply chain disruptions, interest rates remain high, and the industry is still trying to find its footing in the U.S.
What Is an Offshore Electric Power Grid?
Today’s offshore wind projects use a point-to-point, or radial design, where each offshore wind farm is individually connected to the onshore grid.
This method works if a region has only a few projects, but it quickly becomes more expensive due to the cabling and other infrastructure. Its lines are also disruptive to communities and marine life. And it requires more costly onshore grid upgrades.
