The Future of U.S. Offshore Wind: Floating Wind as an Innovative Alternative

The United States is poised to become a major player in offshore wind energy, with federal targets set to install 30 gigawatts (GW) of offshore wind capacity by 2030, including 15 GW of floating offshore wind by 2035. Projections suggest these goals will not be met until 2033 with 14 GW of offshore wind capacity expected in 2030, as projects faced soaring materials costs, high interest rates, and supply chain snags prompting multiple offshore wind companies in the last year to cancel or seek to renegotiate power contracts for planned U.S. offshore wind farms. As the U.S. aims to get back on track, technological innovation through the development of floating offshore wind turbines presents a promising alternative to fixed-bottom structures, offering a more environmentally friendly solution with the potential to revolutionize the U.S. energy landscape.

Floating offshore wind technology, as opposed to traditional fixed-bottom wind turbines, is designed to operate in deeper waters (> 60 m) where fixed structures are not feasible. This technology's adaptability to various marine environments unlocks vast areas for wind energy development, particularly off the U.S. West Coast and in the Gulf of Maine, where deep waters dominate. Moreover, floating wind platforms can have a reduced environmental impact, particularly concerning seabed disruption and marine ecosystems.

Overview of Floating Offshore Wind Configurations

Floating offshore wind turbines are supported by various types of floating platforms, each designed to maintain stability in the open ocean's harsh conditions. The three main configurations include:

1. Spar-buoy Platforms: These platforms consist of a long, vertical cylinder anchored deep into the water, providing stability through ballast. The weight distribution keeps the platform upright and resistant to tilting, even in turbulent conditions.

2. Semi-submersible Platforms: Supported by multiple buoyant columns interconnected by a horizontal structure, these platforms are designed to remain stable through a combination of buoyancy and mooring lines. Their design allows them to be used in a wide range of water depths and wind conditions.

3. Tension Leg Platforms (TLP): These platforms are anchored to the seabed with taut mooring lines, ensuring minimal movement. TLPs are particularly suitable for deeper waters, where traditional anchoring methods are less effective.

These configurations enable floating wind turbines to be deployed in areas previously considered unsuitable for wind energy, such as deep offshore regions. This adaptability not only increases the potential locations for wind farms but also allows for the optimization of wind resource utilization, as deeper waters often experience stronger and more consistent winds.

Environmental Benefits of Floating Offshore Wind

1. Minimal Seabed Disturbance

One of the primary environmental advantages of floating offshore wind turbines is the minimal disturbance they cause to the seabed. Fixed-bottom turbines require extensive piling and anchoring, which can disrupt marine habitats and the natural sediment flow. Their construction can produce dangerously high noise levels in the surrounding aquatic environment which can cause hearing damage to marine mammals.

In contrast, floating platforms have the potential to coexist more harmoniously with marine life, utilizing mooring lines that have a much smaller footprint on the ocean floor, preserving the seabed's ecological integrity. This reduced impact is particularly crucial in regions with sensitive marine ecosystems. Much of the fabrication and assembly work of floating offshore wind turbines can be done in a port and then towed to the site, minimizing the need for complex installation vessels.

2. Enhanced Flexibility and Siting Options

Floating wind technology opens the bulk of the U.S. offshore wind resources for development, including regions far from shore and in deeper waters. These areas often face fewer conflicts with other ocean users, such as commercial shipping and fishing, reducing the potential for environmental and economic conflicts.

Additionally, the ability to site wind farms further offshore can offer a more aesthetically pleasing option and mitigate visual impacts on coastal communities, an issue that has often slowed the deployment of fixed-bottom wind projects. By moving wind farms out of sight, floating technology could foster greater public acceptance of offshore wind energy, accelerating its adoption.

3. Potential for Co-generation and Marine Preservation

Floating offshore wind farms also offer opportunities for co-generation with other renewable energy technologies, such as wave and tidal energy. This co-location can maximize the use of ocean space while minimizing the environmental impact by concentrating energy infrastructure in designated areas.

The Technical Potential of Floating Offshore Wind

According to the National Renewable Energy Laboratory (NREL), the U.S. has a vast offshore wind energy potential, particularly in deep waters suitable for floating wind technology. NREL's 2022 assessment, which evaluated the technical potential of fixed-bottom and floating offshore wind technology across eight coastal regions, exhibited that areas with floating wind potential could contribute significantly to the nation's renewable energy supply, with the technical potential to generate 2.8 terawatts (TW) of electricity—far surpassing the current electricity demand in the U.S.

Data from 2022 National Renewable Energy Laboratory (NREL) Assessment: Offshore Wind Energy Technical Potential for the Contiguous United States

Data from 2022 National Renewable Energy Laboratory (NREL) Assessment: Offshore Wind Energy Technical Potential for the Contiguous United States

The federal target of 15 GW of floating offshore wind by 2035 represents a significant step towards tapping into this potential. Achieving this goal will require advancements in technology, cost reductions, and the development of a robust supply chain. However, the potential is attractive: floating wind could play a monumental role in meeting the U.S.'s clean energy goals while minimizing environmental impacts.

Developments Toward Advancing Floating Offshore Wind in the U.S.

The Biden-Harris Administration has placed an importance on floating offshore wind in the U.S. energy portfolio. The administration's goals include not only the 15 GW target but also initiatives to reduce the cost of floating wind by 70% by 2035 through research, development, and investment. This effort, known as the "Floating Offshore Wind Shot," aims to bring the cost of floating wind energy to $45 per megawatt-hour, making it competitive with other forms of renewable energy.

To advance the U.S. floating offshore wind goals, the Department of Energy (DOE) allocated nearly $50 million, supported by the Bipartisan Infrastructure Law, for research, development, and demonstration projects. This funding includes a $6.85 million innovation challenge to optimize floating wind technologies for large-scale manufacturing and commercialization. Additionally, a $3 million project will develop modeling tools for designing commercial-scale floating wind farms. Another $1 million initiative will address infrastructure challenges on the West Coast by outlining necessary port upgrades for deploying floating wind projects.

Most recently, the DOE announced $16 million in funding to drive innovations in floating offshore wind technology. This initiative seeks to advance the design, manufacturing, and deployment of floating wind turbines, focusing on cost-effective platform designs, improved manufacturing processes, and enhanced deployment techniques. By supporting these advancements, the funding aims to bolster the U.S. economy through job creation and industry growth, while contributing to the Biden-Harris Administration's objective of a carbon-free electricity sector by 2035. This effort positions the United States as a leader in the global floating offshore wind market and encourages diverse applicants from industry, academia, and national laboratories to participate, ultimately accelerating the commercialization and integration of this technology into the national energy grid.

The Bureau of Ocean Energy Management (BOEM) announced Oregon's first offshore wind lease sale on August 29, 2024. Set for October 2024, the auction will feature two areas totaling approximately 195,000 acres, offering up to 3.1 GW of capacity. The depths of the lease areas present an opportunity for the deployment of offshore wind. BOEM revealed in the Federal Register that the five companies eligible to bid are Avangrid Renewables, BlueFloat Energy Oregon, OW North American Ventures, US Mainstream Renewable Power, and South Coast Energy Waters. The agency initially identified these potential lease areas to the public in August 2023. At that time, the areas covered 219,000 acres with a potential capacity of 2.6 GW. One lease area is located 32 miles offshore from Coos Bay, while the other is situated 18 miles offshore from Brookings.

BOEM will hold its first commercial offshore wind lease sale in the Gulf of Main on October 29, 2024. This lease sale represents a significant opportunity for floating offshore wind technology, with the eight lease areas capable of generating over 13 GW combined and stipulations designed to spear the development of a robust domestic U.S. supply chain for floating wind. On August 19, 2024, BOEM announced the execution of the nation’s first floating offshore wind energy research lease (OCS-A 0553). The lease area covers approximately 15,000 acres located 28 nautical miles offshore Maine on the U.S. Outer Continental Shelf with potential for the deployment of up to 12 floating offshore wind turbines capable of generating up to 144 megawatts of renewable energy. The State of Maine designated Pine Tree Offshore Wind, LLC as the operator for the research lease.

In February 2024, Maine Governor Janet Mills announced Searsport as the preferred site for floating offshore wind fabrication, staging, assembly, maintenance, and deployment at Sears Island for floating offshore wind fabrication, staging, assembly, maintenance, and deployment.  Additionally, in July 2024, Maine and Massachusetts made a joint proposal for $200 million to the EPA’s Climate Pollution Reduction Grant program to support critical port infrastructure for floating offshore wind.

Currently in early development, CADEMO is an intriguing 60 MW pilot project in California which will trial two different floating wind base technologies through four floating wind turbines and is expected to begin operations in 2028. The U.S. Department of Defense (DoD) approved the project in early August 2024 allowing the wind farm to be located off the California coast near the Vandenberg Space Force Base. Environmental reviews are pending ahead of the final permit decision by the California State Lands Commission amongst other state and federal agencies.

These initiatives will be foundational for scaling up floating wind deployment and realizing its full potential. Floating offshore wind represents an innovative frontier in the U.S.'s renewable energy journey. With its favorable environmental impact, flexibility in siting, and vast technical potential, floating wind could be the greenest and most sustainable option for expanding offshore wind capacity.