Offshore wind power : wind turbines on the sea

Offshore wind power is a booming renewable energy sector. By harnessing the stronger, more regular winds off the coast, offshore wind has considerable energy potential to contribute to the energy transition and the fight against climate change. This is a recent innovation inwind power, made possible by improved technical capabilities and incentives.

Efficiency and performance

The efficiency of offshore wind turbines is generally higher than that of onshore turbines, due to the quality of the wind in the marine environment. Offshore winds are stronger, more regular and less turbulent than onshore winds, which improves turbine performance and enables them to generate more electricity. According to a study by the International Energy Agency, the average load factor of offshore wind turbines is 40-50%, compared with 20-35% for onshore turbines.

Technologies specific to offshore wind power

Offshore wind power requires specific technologies to withstand harsh weather and marine conditions, such as storms, waves and corrosion. Offshore wind turbines are generally larger and more robust than onshore turbines, with reinforced blades and nacelles to withstand strong winds. Offshore wind turbine foundations are also specific, with steel or concrete structures submerged in water, fixed to the ground or floating.

Floating wind turbines are a major innovation in offshore wind energy, making it possible to harness the wind off deep, steep coasts. These turbines are anchored to the seabed by cables and flotation systems, and can be installed in water depths of over 60 meters.

Challenges and issues facing offshore wind power

Offshore wind power faces a number of technical, economic and environmental challenges:

  • Investment and maintenance costs: Installation and maintenance costs for offshore wind turbines are generally higher than for onshore wind turbines, due to the complexity of operations in the marine environment and the specific technologies required. However, offshore wind power costs have fallen in recent years, thanks to technological advances and increased production volumes.
  • Environmental impacts: Offshore wind power can have impacts on marine wildlife, the seabed and coastal ecosystems, particularly in terms of habitat disturbance, collisions with birds and marine mammals, and underwater noise emissions. It is therefore essential to carry out impact studies and implement appropriate protection and monitoring measures.
  • Social acceptability and conflicts of use: Offshore wind farms can give rise to opposition from local residents, fishermen and tourists, who fear the visual, environmental and economic impacts of offshore wind farms.

There are also the challenges associated withwind power in general, such as intermittency.

Prospects for offshore wind power

The outlook for offshore wind power is promising, particularly in Europe, Asia and the United States. By 2020, installed offshore wind capacity worldwide will have reached around 35 GW, 80% of which will be in Europe. According to the International Energy Agency, offshore wind capacity could reach 200 GW by 2030 and over 1,000 GW by 2050, driven by falling costs, supportive policies and growing demand for renewable energies.

Technological innovations such as floating wind turbines, energy storage systems and smart grids will play a key role in the large-scale deployment of offshore wind and the integration of intermittent renewables into power systems.

At present, onlyhorizontal axis wind turbine (HAWT) projects are planned. I haven’t seen any marine projects forvertical-axis wind turbines,bladeless wind turbines orflying wind turbines.