Offshore Wind: How Offshore Wind Turbines Work and Where They Stand in 2026

Offshore wind puts the largest machines in the renewable energy industry out at sea, where the wind blows harder and more consistently than over land. Europe pioneered it, China now dominates it, and the United States finally connected its first large wind farms in 2026 after a year of legal fights.

This guide explains how offshore wind turbines work, the difference between fixed-bottom and floating designs, the largest wind farms, global capacity, and what is confirmed about US offshore wind as of October 2026.

What is offshore wind?

Offshore wind is electricity generated by wind turbines installed in bodies of water, usually the ocean, and connected to the grid on land by subsea cables. It uses the same physics as onshore wind, but at sea the wind is stronger, steadier and less disrupted by hills, trees and buildings.

That steadier wind is the main reason developers accept the extra cost of building at sea. Equinor reported that its Hywind Scotland floating wind farm achieved a capacity factor of 54% over its first five years, which it called the best of any UK offshore wind farm. Reviews of European experience reach the same conclusion: offshore sites have higher mean wind speeds and lower turbulence than comparable onshore sites, which raises output per turbine (Esteban et al., 2011; Bilgili et al., 2011). A capacity factor is the actual energy produced divided by the maximum the plant could produce running at full power all year.

Offshore wind is a subset of wind power. For the basics of how all wind turbines work, see our guide to wind energy.

How do offshore wind turbines work?

An offshore wind turbine converts the kinetic energy of the wind into electricity with a rotor and generator, then sends that power ashore through a chain of cables and substations.

1. Wind turns the blades. The rotor blades are shaped like aircraft wings; wind passing over them creates lift that spins the rotor.
2. The generator makes electricity. The rotor drives a generator in the nacelle, the housing at the top of the tower. Many large offshore turbines use direct-drive generators with no gearbox.
3. Array cables collect the power. Cables buried in the seabed link each turbine to an offshore substation.
4. The substation steps up voltage. Raising the voltage reduces losses over the long journey to shore.
5. Export cables bring it ashore. One or more export cables carry the power to an onshore substation, where it joins the transmission grid.

Turbine size matters because the energy in wind rises with the swept area of the rotor. Hornsea 2’s turbines are 8 MW each; the first commercial turbine at Coastal Virginia Offshore Wind is rated at 14.7 MW. You can see how rotor size and wind speed change output with our wind turbine calculator.

Fixed-bottom vs floating offshore wind

Fixed-bottom turbines stand on foundations anchored directly in the seabed and are used in shallower water. Floating turbines sit on buoyant platforms held in place by mooring lines and anchors, which allows wind farms in deep water.

Fixed-bottom foundations

Almost all offshore wind capacity today is fixed-bottom. Common foundation types:

• Monopile: a single large steel tube hammered into the seabed. The most common design.
• Jacket: a lattice steel frame, like an oil platform leg, used in deeper water or softer soils.
• Gravity base: a heavy concrete base that rests on the seabed by its own weight.

Floating platforms

Floating wind opens up coastlines where the seabed drops off quickly, such as the US West Coast, Norway and Japan. Common platform types are spar buoys (a tall, ballasted cylinder), semi-submersibles and tension-leg platforms.

Equinor’s Hywind Scotland, a 30 MW, five-turbine project off Peterhead, is the world’s first floating wind farm (Equinor). Siemens Gamesa reported it was installed in water depths between 90 and 120 meters (about 300 to 390 feet). Equinor’s Hywind Tampen in Norway uses 11 floating turbines to supply power to offshore oil and gas platforms.

Feature	Fixed-bottom	Floating
Foundation	Monopile, jacket or gravity base in the seabed	Buoyant platform with mooring lines and anchors
Water depth	Shallower waters	Deep water where fixed foundations are impractical
Maturity	Mature, used for nearly all capacity	Early commercial; small projects in operation
Assembly	Installed at sea by jack-up vessels	Can be assembled in port and towed out
Example	Hornsea 2, UK (1,320 MW)	Hywind Scotland, UK (30 MW)

How much offshore wind is there in the world?

The world had about 83 GW of offshore wind capacity at the end of 2024, according to the Global Wind Energy Council (GWEC). That was about 7.3% of total global wind capacity, with the rest onshore.

About 8 GW was added in 2024, which GWEC called the fourth-highest year on record. The pipeline is much larger: a record 56 GW was awarded in auctions in 2024, and 48 GW was under construction.

Metric (end of 2024)	Value	Source
Global offshore wind capacity	About 83 GW (83.2 GW)	GWEC, Global Offshore Wind Report 2025
Share of all wind capacity	7.3%	GWEC
Capacity added in 2024	About 8 GW	GWEC
Capacity awarded in 2024 auctions	56 GW (record)	GWEC
Under construction	48 GW	GWEC

Which countries lead offshore wind?

China is the clear leader, with about half of global offshore wind capacity, followed by the United Kingdom (GWEC). Germany, the Netherlands and Taiwan complete the top five. Europe built the industry in the 2000s and 2010s in the shallow North Sea, which is ideal for fixed-bottom foundations.

What are the largest offshore wind farms?

The largest operating offshore wind farm in the world is Hornsea 2, about 89 km off the Yorkshire coast in England, at 1,320 MW. It has 165 Siemens Gamesa 8 MW turbines and became fully operational on August 31, 2022 (Guinness World Records).

Wind farm	Location	Capacity	Status
Hornsea 2	North Sea, UK	1,320 MW	Operating since 2022 (largest operating)
Hornsea 1	North Sea, UK	About 1.2 GW	Operating
Hornsea 3	North Sea, UK	About 2.9 GW	Under construction
Coastal Virginia Offshore Wind	Atlantic, Virginia, US	2.6 GW	First power March 2026; full build-out expected by early 2027
Vineyard Wind 1	Atlantic, Massachusetts, US	800 MW	Construction complete, delivering power in 2026

Sources: Guinness World Records, Ørsted, Dominion Energy, Utility Dive. When finished, Hornsea 3 is expected to become the largest single offshore wind farm, and the Hornsea zone as a whole will exceed 5 GW.

What is the status of US offshore wind in 2026?

As of October 2026, the US has four commercial offshore wind farms delivering power, all on the East Coast, but federal policy has shifted firmly against new offshore wind. Projects that were already under construction have continued after winning in court, while new leasing has stopped and several developers have accepted federal payments to give up their leases.

Projects delivering power

Project	State	Capacity	Confirmed status
Block Island Wind Farm	Rhode Island	30 MW	First US offshore wind farm, operating since 2016
South Fork Wind	New York	130 MW	Delivering power to Long Island since early 2024
Revolution Wind	Rhode Island / Connecticut	700 MW	Began delivering power in 2026
Vineyard Wind 1	Massachusetts	800 MW	All 62 turbines built by March 2026; delivering power
Coastal Virginia Offshore Wind	Virginia	2.6 GW	First commercial turbine delivered power March 23, 2026; most turbines expected in service by end of 2026, the rest in early 2027

Sources: Harvard Environmental and Energy Law Program (EELP) tracker, Utility Dive, Dominion Energy, Virginia Mercury. Turbine commissioning is ongoing, so check developers’ updates for current output.

What changed in federal policy

The key events, based on the Harvard EELP federal offshore wind tracker:

1. January 20, 2025: a presidential memorandum withdrew US offshore areas from new wind leasing and ordered a review of existing leases.
2. April 2025: Interior ordered Empire Wind (New York) to stop work. Work later resumed.
3. July 30, 2025: BOEM rescinded all designated offshore Wind Energy Areas.
4. August 22, 2025: BOEM ordered the nearly complete Revolution Wind to stop work; a federal court enjoined the order in September 2025.
5. December 8, 2025: a federal court vacated the government’s pause on wind energy authorizations.
6. December 22, 2025: Interior paused five large East Coast projects (Empire Wind, Revolution Wind, Sunrise Wind, Coastal Virginia Offshore Wind and Vineyard Wind 1), citing national security.
7. January to February 2026: courts granted preliminary injunctions to all five, allowing construction to resume. Interior later let its deadline to appeal those rulings lapse.
8. March to August 2026: Interior reached buyout agreements under which TotalEnergies, Bluepoint Wind, Golden State Wind, Invenergy, Duke Energy and RWE agreed to relinquish leases in return for federal payments. California and other states have challenged some of these buyouts.

Why is offshore wind struggling, and what are the objections?

Offshore wind has been squeezed by two separate forces: rising costs worldwide since 2022, and, in the US, federal policy that turned against the industry in 2025. In late 2023 Ørsted cancelled its Ocean Wind 1 and 2 projects off New Jersey, citing high inflation, rising interest rates, supply-chain delays and a shortage of installation vessels (Utility Dive). Ørsted and its peers are compared in our guide to renewable energy companies.

The objections raised against offshore wind fall into a few stated categories:

• Cost and electricity prices, the same economics that hit Ocean Wind.
• Fishing and navigation conflicts, a major source of local opposition (see the environmental section below).
• Marine life, especially whales, although NOAA Fisheries reports no known link between whale deaths and offshore wind activities.
• National security: the December 22, 2025 pause cited radar “clutter” from moving blades and reflective towers, based on Defense Department reports (ABC13). Developers responded that the Defense Department had been consulted during permitting, and courts allowed all five projects to resume.
• Views from the coast, which push projects further offshore.

How big is offshore wind in US electricity?

Still very small. Wind as a whole supplied about 11% of US utility-scale electricity in 2025 (EIA), almost entirely from onshore turbines in the Great Plains, Texas and the Midwest. Once Coastal Virginia Offshore Wind, Vineyard Wind 1 and Revolution Wind are fully running, offshore wind will matter most to the electricity supply of the Northeast and Virginia.

History of offshore wind

Offshore wind began as a small Danish experiment in 1991 and grew into an industry of more than 80 GW in about three decades. Each step answered the same question: how far from shore, and how deep, can turbines go?

Denmark’s Vindeby, off the island of Lolland, connected 11 turbines to the grid in 1991 and is recognized as the world’s first offshore wind farm. It ran for about 25 years before Ørsted dismantled it in 2017 (Ørsted). Its total capacity was just under 5 MW, smaller than a single turbine at a modern project.

The first large-scale farm came in 2002, when Horns Rev 1 in the Danish North Sea put 80 Vestas 2 MW turbines into operation, about 160 MW (PNNL Tethys). Through the 2000s and 2010s the UK, Germany, the Netherlands and Belgium built ever-larger fixed-bottom projects in the shallow North Sea, and China began building at scale in the late 2010s.

Floating wind followed a separate path. Equinor (then StatoilHydro) installed Hywind Demo, a single 2.3 MW turbine on a spar buoy off Karmøy, Norway, in 2009 (PNNL Tethys). That led to Hywind Scotland, the first floating wind farm, commissioned in 2017 (Equinor).

The US arrived late. The 30 MW Block Island Wind Farm off Rhode Island began commercial operation in December 2016 (POWER Magazine), followed by South Fork Wind in 2024 and the first large East Coast farms in 2026 (Harvard EELP).

Year	Milestone	Source
1991	Vindeby, Denmark: 11 turbines, world’s first offshore wind farm	Ørsted
2002	Horns Rev 1, Denmark: first large-scale offshore farm, about 160 MW	PNNL Tethys
2009	Hywind Demo: first full-scale floating wind turbine, 2.3 MW, Norway	PNNL Tethys
2016	Block Island, Rhode Island: first US offshore wind farm, 30 MW	POWER Magazine
2017	Hywind Scotland: world’s first floating wind farm, 30 MW	Equinor
2017	Vindeby decommissioned after about 25 years	Ørsted
2022	Hornsea 2 (1,320 MW) fully operational, largest operating farm	Guinness World Records
2024	Global offshore capacity reaches about 83 GW	GWEC
2026	Coastal Virginia Offshore Wind delivers first power (March 23)	Virginia Mercury

Offshore wind vs onshore wind

Offshore wind trades higher construction and maintenance costs for stronger winds, bigger turbines and sites close to large coastal cities. Onshore wind is cheaper and faster to build but competes for land and faces local opposition.

Feature	Offshore wind	Onshore wind
Wind resource	Stronger and steadier	More variable, affected by terrain
Turbine size	Very large (8 to 15 MW class in recent projects)	Smaller
Construction	Specialized vessels, subsea cables, offshore substations	Roads, cranes, standard grid connection
Maintenance	By boat or helicopter, weather-limited	By road
Proximity to demand	Close to coastal cities	Often far from cities, needs long transmission
Main concerns	Cost, marine life, fishing, views	Land use, noise, wildlife, views

The full list of trade-offs for wind in general is in wind energy pros and cons.

What are the environmental impacts of offshore wind?

Offshore wind produces no emissions while operating, but construction noise, seabed disturbance and interactions with fishing, birds and marine mammals all need managing.

• Construction noise. Pile driving for monopiles is loud underwater. Projects use seasonal restrictions, bubble curtains and protected species observers to reduce harm to marine mammals.
• Whales. NOAA Fisheries states there are no known links between large whale deaths and ongoing offshore wind activities, and that it has not authorized death or serious injury of whales for any wind-related action.
• Seabed and habitat. Foundations and scour protection change the seabed locally; they can also act as artificial reefs that attract fish. A review of lessons from assessing offshore wind impacts on marine mammals and seabirds recommends judging effects at the population level, measuring responses to both construction and operation, and accounting for cumulative impacts as more farms are built (Bailey, Brookes & Thompson, 2014).
• Birds and bats. Collision risk exists and is assessed site by site.
• Fishing and navigation. Turbine spacing, cable routes and exclusion zones affect commercial fishing, a major source of local opposition.

Is offshore wind worth it?

Offshore wind is worth building where coastlines have strong winds and dense populations, little spare land, and grid operators who need large amounts of clean power close to demand. Northern Europe and China have reached that conclusion at scale; the US remains split.

The case for offshore wind rests on output: steady winds, high capacity factors and huge turbines deliver a lot of energy per project. The case against rests on cost, supply-chain bottlenecks, and local and political opposition. If you are curious how much energy a turbine produces in kilowatthours, try the kWh calculator alongside the wind turbine calculator. For a small machine on your own property, see our guide to a home wind turbine. For pay and training, see wind turbine technician careers.

Scientific references

• Esteban, M. D., Diez, J. J., López, J. S., & Negro, V. (2011). “Why offshore wind energy?” Renewable Energy, 36(2), 444–450. doi:10.1016/j.renene.2010.07.009
• Bilgili, M., Yasar, A., & Simsek, E. (2011). “Offshore wind power development in Europe and its comparison with onshore counterpart.” Renewable and Sustainable Energy Reviews, 15(2), 905–915. doi:10.1016/j.rser.2010.11.006
• Bailey, H., Brookes, K. L., & Thompson, P. M. (2014). “Assessing environmental impacts of offshore wind farms: lessons learned and recommendations for the future.” Aquatic Biosystems, 10, 8. doi:10.1186/2046-9063-10-8
• Manwell, J. F., McGowan, J. G., & Rogers, A. L. (2009). Wind Energy Explained: Theory, Design and Application (2nd ed.). Wiley. doi:10.1002/9781119994367

Bottom line

Offshore wind uses giant turbines at sea to capture stronger, steadier wind. The world had about 83 GW installed at the end of 2024 (GWEC), led by China and the UK, and the largest operating farm is the 1,320 MW Hornsea 2. Fixed-bottom foundations dominate today; floating platforms are opening up deep water.

In the US, Block Island, South Fork, Revolution Wind, Vineyard Wind 1 and Coastal Virginia Offshore Wind are delivering power in 2026 after all five December 2025 stop-work orders were blocked in court, but new federal leasing has stopped and several leases have been bought back. For how offshore wind compares with every other clean source, visit our renewable energy homepage or the renewable energy sources guide.