With a burgeoning human population creating an ever-increasing demand for energy, technological advancements aim to harness the natural forces of the planet to generate power. Offshore wind turbines constitute one such technology. As a renewable source of energy, offshore wind has the significant benefit of not being depleted through use in contrast to nonrenewable sources such as fossil fuels. Moreover, unlike fossil fuels, energy produced by offshore wind also benefits the environment by creating zero emissions. While offshore wind turbines present their own set of concerns which warrant consideration, the turbines are a promising technology that should be beneficial to the world’s quest to meet its energy needs while minimizing the harm done to the environment.

An International Presence

Although the U.S. has begun to install offshore wind turbines, other countries embraced this technology sooner. The U.K., Germany and China lead the offshore wind industry, with the U.K. and Germany installing 44% and 34% of Europe’s 5,402 offshore wind turbines respectively. In addition, China has accelerated the pace of its deployment of offshore wind turbines installing enough turbines in 2020 to produce 3,000 new megawatts (million watts) of electricity. Denmark, Belgium, and the Netherlands have also constructed a significant number of wind turbines, the first of which became operational in 1991. At present, the U.S. has seven offshore wind turbines installed and operating which produce just 42 megawatts of electricity.

How Do Offshore Wind Turbines Work?

Wind turbines are in effect modernized windmills designed for producing electricity. Offshore wind turbines have been constructed primarily during this century and are situated in bodies of water miles from shore. In the U.S., the federal government engages in lease sales for specified federal waters with corporations and partnerships, which install and maintain the turbines. Turbine manufacturers assemble the offshore wind turbine components at seaport facilities specifically built for this purpose. The turbines consist in part of long turbine blades (exceeding 100 yards in length), large nose cones (nacelles), and very heavy steel columns (monopiles). Barges and ships carry these components to the designated site for installation. Internationally these sites lie on average 30 kilometers (approximately 20 miles) from shore. In the best weather conditions, turbines are visible up to 26 miles from shore. (The seven existing U.S. offshore wind turbines are significantly closer to shore.) In shallower waters (up to 60 meters), the turbines are attached to the seabed with a fixed foundation. In deeper waters, the companies installing the wind turbines use floating offshore wind platforms. With both fixed foundation and wind platform turbines, workers bury cables attached to the turbines under the seafloor. Through these cables, the power produced by the turbines travels to facilities in coastal cities, where load centers distribute it into the electrical grid.

Pros and Cons

Pros

Offshore wind turbines share a number of strengths with land-based wind turbines. In addition to providing renewable energy while emitting no greenhouse gases, both offshore and land-based wind turbines provide a domestic source of energy and create jobs all without using water. Offshore wind turbines do however offer numerous advantages over land-based wind turbines. As offshore turbine components are transported by barges and ships, they avoid the challenges encountered in moving land-based turbine components to their installation sites, such as narrow roads and tunnels. For this reason, the components for offshore wind turbines can be larger and yield more energy. At the same time, because these turbines lie many miles offshore, their acoustic and visual impact is less than land-based turbines. Furthermore, wind tends to move at higher speeds over water than over land due to the lack of barriers, and the higher wind speeds result in greater energy production. Similarly, wind blows more steadily offshore than on land yielding a more reliable energy source. The U.S. population tends to live in coastal cities, which is where offshore wind energy enters the electrical grid. Thus offshore wind energy can be readily available where it is needed most.

Cons 

The disadvantages of offshore wind turbines merit attention. Since the offshore wind industry is relatively young, its environmental impacts are still being assessed. Commercial fishermen are concerned that wind farms in the vicinity of their fishing operations will pose problems with equipment and navigation, as well as with fish and shellfish populations. Conservationists worry the turbines will kill large numbers of birds and negatively impact marine life, such as endangered whale species. Furthermore waterfront property owners argue the turbines will diminish views from, and decrease the values of, their property. Those in the tourism industry have similar concerns. Owing in part to concerns like these, the review process for proposed offshore wind turbines is lengthy and uncertain. The Cape Wind Energy project exemplifies this. In 2001, Cape Wind submitted an application to construct up to 130 wind turbines off the shores of Massachusetts. After engaging in numerous efforts to secure all necessary governmental approvals and encountering local opposition, Cape Wind also experienced difficulty with obtaining financing and terminated the project in 2017. Indeed, once governmental entities have completed required reviews of proposed offshore wind turbines, the challenges and expense of building and maintaining them remain. This construction and maintenance requires very specialized and expensive equipment because of the turbines’ offshore location. Similarly, the placement of power cables beneath the seafloor generates significant expense. Deeper water depths compound all of these challenges. Offshore wind turbine components must also be built with greater redundancy to address the difficulty of gaining access to the site for maintenance. Moreover, the motion of the waves, as well as very high winds during storms and hurricanes, can damage the turbines.

Addressing Challenges

Technology

The offshore wind industry is pursuing technological advancements to overcome some of the challenges it faces. Primary among these advancements are floating offshore wind platforms. Rather than attaching the turbines’ foundations to the seabed (which is impractical in waters over 60 meters deep), the companies can utilize floating offshore platforms. Engineers have developed three types of floating offshore platforms: semi-submersible, tension leg platform, and spar-buoy. These new technologies allow for the installation of wind turbines in much deeper waters, which is where the majority of U.S. sites suited to offshore wind power are located. Furthermore, siting the wind turbines at a greater distance from shore renders them less visible from land and thereby addresses some of the concerns of property owners and the tourism industry.

Research

The U.S. government seeks to address concerns about offshore wind turbines through scientific research and monitoring. On October 13, the U.S. Department of Energy (DOE) announced $13.5 million in funding for four research projects focused on offshore wind turbines. These projects will assess the impact of offshore wind turbines on wildlife and the environment with the goal of reducing such impacts through improved scientific understanding. Two of the projects focus on the east coast and will investigate wind turbine impacts on birds, bats, and commercial fish, as well as marine mammals and invertebrates. In the other two projects, researchers will study similar issues on the west coast. Similarly, DOE has initiated the U.S. Offshore Wind Synthesis of Environmental Effects Research (SEER) project. This project seeks to provide information to stakeholders and also gather feedback from them. In addition, the project will analyze research conducted on offshore wind turbines in the U.S. and abroad to determine the wildlife and environmental issues in greatest need of further research. These same efforts are expected to yield information regarding monitoring tools and mitigation strategies.

U.S. Plans for Offshore Wind Power

Last March, the new administration in Washington, D.C. established the goal of deploying 30,000 megawatts of offshore wind power in the U.S. by 2030. As a step toward achieving this goal, in October, the current administration announced plans to develop up to seven offshore wind farms. More specifically, the Department of Interior (DOI) intends to hold lease sales by 2025 in the gulfs of Maine and Mexico, the New York Bight and Central Atlantic, as well as off the coasts of Oregon, California, and the Carolinas. This significant commitment to the development of offshore wind power was preceded in May by DOI’s approval of the Vineyard Wind project, which will be sited off the coast of Massachusetts and the country’s first large-scale offshore wind power project. DOI’s written decision approving the Vineyard Wind project includes mitigation measures aimed at avoiding, reducing, and eliminating negative effects from the project. The wind farm developers have also agreed to place their turbines one nautical mile apart to address fishermen’s navigation concerns. Similarly, the developers will curtail construction during many months of the year and employ an underwater curtain of bubbles, with both measures designed to limit disturbances experienced by whales in the area of the wind farm. More recently, in November, DOI approved the South Fork Wind project, the second major U.S. offshore wind project. The wind farm, to be located off the coast of Rhode Island, will generate power for New York’s Long Island. As with the Vineyard Wind project, DOI’s written decision approving the South Fork Wind project includes mitigation measures aimed at avoiding, reducing, and mitigating negative effects from the construction and operation of the project.

Future Prospects

The U.S. has approached offshore wind power with greater caution than some countries. Given the disadvantages of this source of power, this hesitancy is unsurprising. Yet, as a renewable source of energy, offshore wind power calls for concerted efforts to overcome its weaknesses through technological advancements, scientific research, and mitigation strategies. Concurrent with its declaration to now actively pursue this renewable energy source, the U.S. has made clear its commitment to address concerns about offshore wind power. This stance proffers hope that offshore wind power can assist the country in meeting its energy needs while also avoiding the emission of additional greenhouse gases into the atmosphere.

SOURCES 

American Geosciences Institute. What are the advantages and disadvantages of offshore wind farms? Retrieved from https://www.americangeosciences.org/critical-issues/faq/what-are-advantages-and-disadvantages-offshore-wind-farms 

Daly, M. (2021, October 13). New wind farms would dot U.S. coastlines under Biden plan. Los Angeles Times.  Retrieved from https://www.latimes.com/world-nation/story/2021-10-13/new-wind-farms-would-dot-u-s-coastlines-under-biden-plan 

Davenport, C. (2021, October 13). Biden Administration Plans Wind Farms Along Nearly the Entire U.S. Coastline. The New York Times. Retrieved from https://www.nytimes.com/2021/10/13/climate/biden-offshore-wind-farms.html 

Environmental and Energy Study Institute. (2010, October). Offshore Wind Energy [Fact sheet]. Retrieved from https://www.eesi.org/files/offshore_wind_101310.pdf 

Grandoni, D. (2021, November 24). Biden administration approves first offshore wind farm to supply power to New York. The Washington Post. Retrieved from https://www.washingtonpost.com/climate-environment/2021/11/24/biden-offshore-wind-new-york/ 

Iberdrola. What is offshore wind energy. Retrieved from https://www.iberdrola.com/sustainability/how-does-offshore-wind-energy-work 

Morrison, J. (2021, October 25). Virginia unveils $200 million wind facility. The Washington Post. Retrieved from https://www.washingtonpost.com/local/virginia-politics/200-million-wind-turbine-facility-planned-for-virginia/2021/10/25/b8ce4714-359a-11ec-8be3-e14aaacfa8ac_story.html 

Partlow, J. (2021, May 8). Biden wants to move energy offshore, but choppy seas are ahead. The Washington Post. Retrieved from https://www.washingtonpost.com/nation/2021/05/08/biden-wants-move-energy-offshore-choppy-seas-are-ahead/ 

The White House. (2021, March 29). Biden Administration Jumpstarts Offshore Wind Energy Projects to Create Jobs [Fact sheet]. Retrieved from https://www.whitehouse.gov/briefing-room/statements-releases/2021/03/29/fact-sheet-biden-administration-jumpstarts-offshore-wind-energy-projects-to-create-jobs/ 

U.S. Department of Energy. (2021, October 13). DOE Announces $13.5 Million for Sustainable Development of Offshore Wind. Retrieved from https://www.energy.gov/articles/doe-announces-135-million-sustainable-development-offshore-wind 

U.S. Department of Energy, Wind Energy Technologies Office. (2021, November 8). Atlantic Offshore Wind Transmission Study Will Inform Options to Support National Goals. Retrieved from https://www.energy.gov/eere/wind/articles/atlantic-offshore-wind-transmission-study-will-inform-options-support-national

U.S. Department of Energy, Wind Energy Technologies Office. (2021, October 13). Spotlight on SEER: Awareness for Offshore Wind Development. Retrieved from https://www.energy.gov/eere/wind/articles/spotlight-seer-awareness-offshore-wind-energy-development 

U.S. Department of Energy, Wind Energy Technologies Office. (2021, August 30). Top 10 Things You Didn’t Know About Offshore Wind Energy. Retrieved from https://www.energy.gov/eere/wind/articles/top-10-things-you-didnt-know-about-offshore-wind-energy 

U.S. Department of Interior. (2021, November 24). Interior Department Approves Second Major Offshore Wind Project in U.S. Federal Waters [Press release]. Retrieved from https://www.doi.gov/pressreleases/interior-department-approves-second-major-offshore-wind-project-us-federal-waters 

U.S. Department of Interior. (2021, October 28). Interior Department Takes Action to Advance Offshore Wind in the Atlantic and Gulf of Mexico [Press release]. Retrieved from https://www.doi.gov/pressreleases/interior-department-takes-action-advance-offshore-wind-atlantic-and-gulf-mexico

U.S. Department of Interior. (2021, October 13). Secretary Haaland Outlines Ambitious Offshore Wind Leasing Strategy [Press release]. Retrieved from https://www.doi.gov/pressreleases/secretary-haaland-outlines-ambitious-offshore-wind-leasing-strategy 

U.S. Department of Interior. (2021, May 11). Biden-Harris Administration Approves First Major Offshore Wind Project in U.S. Waters [Press release]. Retrieved from https://www.doi.gov/pressreleases/biden-harris-administration-approves-first-major-offshore-wind-project-us-waters

U.S. Department of Interior, Bureau of Ocean Energy Management. (2015, September) Cape Wind Energy Project [Fact sheet]. Retrieved from https://www.boem.gov/sites/default/files/renewable-energy-program/Studies/Cape-Wind-Fact-Sheet—Sept-2015-clean-%281%29.pdf 

U.S. Department of Interior, Bureau of Ocean Energy Management. Cape Wind. Retrieved from https://www.boem.gov/renewable-energy/studies/cape-wind

Wind Europe. (2021, February 8). Offshore wind in Europe – key trends and statistics 2020. Retrieved from https://windeurope.org/intelligence-platform/product/offshore-wind-in-europe-key-trends-and-statistics-2020/