Humans have utilised wind power for thousands of years, from propelling sailing ships to grinding grain with windmills [1]. The modern offshore wind industry began in 1991 with ten turbines off the coast of Denmark. Since then, offshore wind farms have expanded significantly. In 2023, there were 292 projects worldwide, generating 59,009 MW of power [2]. The global offshore wind capacity is constantly expanding, with additions expected to reach 19 GW in 2025 and sector-wide expenditure due to hit $80 billion [3].
The scale of offshore wind power
Offshore wind turbines stand out in size, construction, and setup. These turbines are often over 800 feet tall, with long blades that capture stronger and more consistent ocean winds [4]. Transporting the components to the sea is a complex process due to their size, requiring specialised ships, equipment and crews [5]. Environmental assessments and input from local communities further extend the timeline, and, as a result, it can take a decade or more to complete an offshore wind project. However, once operational, these turbines provide a reliable, long-term renewable energy source, delivering significant environmental and economic benefits.
How offshore wind turbines generate power
Offshore wind turbines convert wind energy into electricity using advanced aerodynamics and electromechanical systems [6]. As the wind spins the blades, their motion powers a generator through a gearbox or direct drive, turning mechanical energy into electricity. This electricity travels via underwater cables to an offshore substation for stabilisation before being sent through export cables to onshore substations, where it integrates into the grid for distribution.
The role of foundations and substations
Offshore wind turbines are anchored to the seabed using various foundation types, such as monopiles, jackets, or gravity-based structures [7]. These foundations offer stability against ocean currents and harsh weather conditions. An offshore substation has a key role in collecting power from multiple turbines, increasing voltage and transmitting it efficiently to the shore via buried subsea cables [8].
The benefits of offshore wind energy
Offshore wind energy has many advantages. For example, more energy can be produced as winds over the sea tend to be stronger and far more consistent than on land. While offshore wind farms need some onshore infrastructure, such as pre-assembly yards, substations, transmission lines, and sometimes storage, they still occupy less overall onshore space, making them a suitable option for crowded coastal areas. They also help reduce reliance on fossil fuels and support renewable energy goals [9]. Plus, offshore wind projects create jobs in manufacturing, construction and maintenance – boosting local economies [10].
Challenges and future prospects
Even though offshore wind energy has plenty of benefits, it still faces challenges like high construction costs, potential environmental impacts, and regulatory hurdles. However, technological advancements and strong government support are making it more viable. With continued investment and innovation, offshore wind is set to play an even greater role in the global transition to clean energy, helping to create a more sustainable, carbon-free future.
References:
- https://offshorewindmaryland.org/how-offshore-wind-works/
- https://www.energy.gov/eere/wind/articles/offshore-wind-market-report-2023-edition#:~:text=Offshore%20Wind%20Powering%20Up,over%2011%2C900%20operating%20wind%20turbines.
- https://www.offshorewind.biz/2025/03/04/global-offshore-wind-to-rebound-in-2025-adding-19-gw-of-capacity-rystad-energy/
- https://offshorewindmaryland.org/how-offshore-wind-works/
- ibid.
- https://www.energy.gov/eere/wind/how-do-wind-turbines-work
- https://www.nyserda.ny.gov/All-Programs/Offshore-Wind/About-Offshore-Wind/Offshore-Wind-101
- ibid.
- ibid.
- https://us.orsted.com/renewable-energy-solutions/offshore-wind/what-is-offshore-wind-power/how-do-offshore-wind-turbines-work#keeping
