How large would the offshore wind turbines be?

We do not yet know the exact size of the wind turbines proposed for the Humboldt Wind Energy Area (WEA) (1), as no specifics have been yet proposed by the developers. However, based on the other projects currently planned around the world, each wind turbine would likely stand (2) (or float) at least 900 feet above the ocean’s surface (about 90 stories, or almost as tall as the Eiffel Tower) with (3) a rotor diameter of about 775 feet and a swept area of more than 470,000 square feet (the size of Image courtesy of Abigail Lowell / EPIC more than eight American football fields). For a more local reference point, the former pulp mill smokestack in Samoa is about 270 feet tall, so the wind turbines would likely be at least about three times that height.

Wind turbines continue to increase in size with new and emerging engineering innovations, and developers are likely to build the tallest turbines physically and economically possible at the date of installation,

with current aims for at least 20-megawatt (MW) turbines that could power between 4.5-6 million homes for a whole year. In 2023 the Chinese company Ming Yang Smart Energy Group presented a conceptual 22-MW turbine called the MySE 22MW (4), which is projected to be 1,050 feet tall with a rotor diameter of 1,017 feet and a swept area of more than 800,000 square feet. The efficiency and economic value gained from producing larger turbines has resulted in significant technological advancements in the wind energy sector. In 2024, multiple 20+ megawatt turbine prototypes have been announced (5), from companies worldwide. As of December of 2024, a renewable energy company in Denmark, Siemens Gamesa, was in the process of finalizing the installation of a 21-MW offshore wind turbine prototype in their local testing facility. Separately, the Ming Yang Smart Energy Group, a Chinese power manufacturing company, developed a prototype for a 26-MW offshore wind turbine intended for areas with 8m/s wind speeds or higher in October of 2024. They project a single unit annually to harvest enough energy to power upwards of 55,000 homes.

One advantage of larger wind turbines is that they produce more energy per rotation than smaller wind turbines, such that they produce more energy using fewer materials and less sea space (6). This means that you can generate more electricity using less steel, fewer cables, fewer maintenance trips, and all of the other aspects of offshore wind that cause environmental impacts. This greatly reduces the amount of environmental impact (6) per megawatt of electricity generated. Taller turbines can also access faster, more consistent winds farther away from the friction of the air-sea interface. Of course, larger wind turbines will cause greater visual impacts while the turbine is being constructed and stored in the bay awaiting installation due to their greater size. Current plans indicate that there would be space for up to 12 turbines to be stored in the bay at any given time.

Watch the video below about why floating offshore wind turbines are so large, and only getting bigger (7):

References​

1. Bureau of Ocean Energy Management. (n.d.). Humboldt Wind Energy Area. www.boem.gov/renewable-energy/state-activities/humboldt-wind-energy-area 

2. Lazo, A. (2024, February 8). Legislators unveil measure to ask voters for $1 billion offshore wind bond. CalMatters. https://calmatters.org/environment/2024/02/offshore-wind-bond-california/ 

3. Vestas. (2024). V236-15.0 MW™. www.vestas.com/en/energy-solutions/offshore-wind-turbines/V236-15MW 

4. Renewables Now. (2023, October 23). Mingyang presents 22-MW offshore wind turbine concept. https://renewablesnow.com/news/mingyang-presents-22-mw-offshore-wind-turbine-concept-837415/ 

5. Buljan, A. (2025, January 1). Offshore wind turbines in 2024: 20+ MW prototypes rolling out in Europe, China; 16 MW remains most powerful turbine installed offshore. Offshore Wind. https://www.offshorewind.biz/2025/01/01/offshore-wind-turbines-in-2024-20-mw-prototypes-rolling-out-in-europe-china-16-mw-remains-most-powerful-turbine-installed-offshore/

6. Akhtar, N., Geyer, B., Schrum, C. (2024). Larger wind turbines as a solution to reduce environmental impacts. Sci Rep, 14: 6608. https://doi.org/10.1038/s41598-024-56731-w 

7. Undecided with Matt Ferrell. (2023, April 25). Why Are Floating Wind Turbines So Huge? [Video]. YouTube. www.youtube.com/watch?v=83FqqfODmmg