The world's largest offshore wind farm, with several Ørsted wind turbines standing in rows in dark blue ocean.

Offshore wind energy

Offshore wind power plays an indispensable role in the global green energy transition.

In just a few decades, offshore wind has gone from being an untested idea to a mature and competitive technology.

In Denmark, where Ørsted is headquartered, offshore wind power has reduced carbon emissions and developed a new industry that employs thousands of people throughout the country.

In 1991, we built the world’s first offshore wind farm, Vindeby, in the shallow waters of Lolland, Denmark. With eleven small wind turbines, this wind farm could power almost 2,200 households' energy consumption. Today’s turbines are significantly larger and more efficient. Just one turbine at one of our new wind farms can produce more electricity than the entire Vindeby wind farm could back then.

Size comparison between various Ørsted wind turbines and the Statue of Liberty and Victoria Art Center Spine.

Electromagnetism in offshore wind turbines

Electrical energy can be generated by rotating magnets inside a coil of conductive wire. The big question is how to achieve that rotation.

In conventional power stations, fossil fuels like coal, gas and oil are burnt to heat water, producing high pressure steam that can drive a turbine and, in turn, an electrical generator.

Unfortunately, this also produces carbon dioxide, other harmful emissions, and relies on finite resources that need to be constantly extracted and transported to a power station. In a wind turbine, the rotation is achieved through the clean, natural, and ultimately unlimited power of the wind.

Illustrative walkthrough of the different components of Ørsted wind turbines, ranging from the foundation to rotor blades.

How do we bring wind power ashore?

Each wind turbine sends its power through cables down the tower and under the seabed to an offshore substation. Here the energy is stepped up to a higher voltage ready to send ashore via high-voltage cables. Higher voltage means less energy is lost in transmission.

On land, another substation adjusts the voltage again so that the electricity can be fed into the grid and distributed via power lines to the homes and businesses that need it.

Learn more about what happens when the power reaches land

Illustrative walkthrough of how power is generated from wind turbines and transfered to peoples' homes

Frequently asked questions

  • How do wind turbines turn wind into electricity?
    When the wind blows on the blades of the turbine, it causes them to rotate. This rotation is turned into electricity using the principle of electromagnetism, where magnets are rotated inside a coil of conductive wire. The electrical energy is then sent ashore through cables where it can be used by homes and businesses.
  • What is wind energy used for?
    Wind energy can be used for anything that needs electricity, from supplying homes and businesses to lighting streetlights, powering mass transit or charging electric cars. It can also be used to produce carbon-neutral synthetic fuels and green hydrogen that can be burnt for processes that can’t be electrified. Learn more about green hydrogen on our global website.
  • How does wind energy power my home?
    Power from wind turbines feeds into the regional or national electricity grid, along with power from other sources, like solar farms and conventional power plants. When you use electricity in your home, the energy comes through the grid from this mix of sources
  • How reliable is wind energy?
    Offshore wind power is more reliable than you might think. The wind blows much more consistently out at sea, and the turbines are designed to generate power even from a very light breeze. In the rare case that there really isn’t enough wind, other sources of power that contribute to the grid can compensate for this. Even in a future world that runs entirely on green energy, offshore wind won’t be the only energy source.
  • How clean is wind energy?
    Offshore wind is very clean because it provides an emissions-free alternative to fossil fuel-based energy generation. Some one-off emissions are produced in the manufacture and installation of offshore wind turbines. But over its lifetime, an offshore wind farm emits 99% less carbon dioxide than coal-based power stations for the equivalent amount of power production.
  • How much energy does offshore wind produce?
    Offshore wind technology has been around for about 30 years now. In that time, the capacity of the wind turbines has increased significantly. So too has the number of wind turbines we’re able to install at one wind farm. As a consequence, a large new offshore wind farm built today can produce at least as much energy as a conventional power station.
  • Is offshore wind good for the environment?
    Yes. Offshore wind is good for the environment because it generates electricity without burning any fuel or emitting any carbon dioxide.
  • Can you hear or see the offshore wind turbines?
    Usually, offshore wind is located many kilometres out at sea, it can hardly be seen from the shore, and can’t be heard at all. What is the main benefit of capturing wind out at sea? The wind at sea is stronger, more consistent, and less turbulent than on land. This means more power can be generated more reliably.
  • Why are you building wind farms in the sea rather than on land?
    It’s possible to transport much larger towers and blades by boat than by road, making it easier to construct much larger wind turbines, generating more power. The sea is a huge area with plenty of space to construct large numbers of turbines, while avoiding shipping routes or ecologically sensitive areas.
  • What do we do with old offshore wind farms?

    When an offshore wind farm eventually reaches the end of its lifespan, it’s either decommissioned, life-extended, or repowered. While life extension involves repairing and maintaining the existing wind turbines for further years of service, both decommissioning and repowering mean removing the old turbines.

    Repowering involves replacing the old turbines with the latest larger and more efficient models, while decommissioning means completely dismantling the wind farm. In either case, the old turbines need to be removed. At present, up to 95% of a wind turbine can be recycled, with the lightweight blades proving more challenging. In 2021, Ørsted committed to send no more blades.

  • What about the impact on birds?
    Wind turbines pose only a tiny danger to bird life. Far greater is climate change, which threatens many species with extinction. Wind power is an important way of reducing that threat. At present, up to 95% of a wind turbine can be recycled, with the lightweight blades proving more challenging. In 2021, Ørsted committed to send no more blades to landfill, but instead to explore options for reuse and recycling.
  • Will my property lose value if there is an offshore wind farm nearby?
    Offshore wind farms are generally located far out at sea with very little impact on the view. Studies reveal that offshore wind has little to no influence on property prices.
  • How can offshore energy coexist with fishing industry?
    Offshore wind already coexists successfully with maritime and fishing industries, with close collaboration throughout development, construction and operation.
A row of wind turbines standing next to the shoreline with birds flying next to them.

Our green energy transformation

One of the world's most sustainable energy companies

In just ten years, we transformed our business from one of the most fossil fuel-intensive to a company 100% focused on renewables.