Big Bubble Curtain: Protecting Marine Life During Offshore Wind Expansion

As the global expansion of offshore wind farms accelerates, so does the awareness of the need to protect marine ecosystems. One of the biggest environmental challenges during wind farm construction is underwater noise—especially from pile driving the foundations into the seabed. A highly effective solution has emerged: the Big Bubble Curtain.

What Is the Big Bubble Curtain?

The Big Bubble Curtain (BBC) is a system of perforated hoses laid on the seabed around the construction site. Air is pumped through these hoses, rising in the form of bubbles to create a kind of “soundproof wall” in the water. This bubble wall alters the propagation of sound waves by reducing and reflecting their energy—similar to an acoustic barrier.

Why Is Underwater Noise Protection Necessary?

Marine mammals such as the harbor porpoise, native to the North and Baltic Seas, are highly sensitive to noise. They rely on sound for orientation, communication, and foraging. Construction noise from offshore wind farms can disorient, drive away, or even injure them.

• Underwater noise in the North and Baltic Seas has doubled every 10 years over the past 35 years.

• At sound pressure levels above 160 dB re 1 µPa, harbor porpoises show behavioral changes; at 180 dB, physiological damage is possible.

• Studies show that the Big Bubble Curtain can reduce sound pressure levels by up to 20 dB, enough to protect marine life and comply with legal limits.

Where Is It Required?

Several countries have made the use of noise mitigation systems like the Big Bubble Curtain mandatory or strongly recommended during offshore wind construction:

• Germany: Mandatory above 160 dB according to BSH regulations.

• Netherlands, Belgium, Denmark: Environmental laws require noise mitigation.

• USA (e.g., California): Environmental impact assessments increasingly demand noise protection.

• United Kingdom: Recommended as part of environmental permitting.

• Taiwan, South Korea, China: Increasingly adopting ecological standards for offshore projects.

Market Outlook: A Growing Need

With Europe aiming to reach 300 GW of offshore wind capacity by 2050, the demand for noise mitigation technologies like the Big Bubble Curtain is set to grow rapidly.

Global Forecasts:

• Global offshore wind capacity was around 75 GW in 2024.

• According to IRENA, it is expected to reach 500 GW by 2030—a 14-fold increase from 2020.

• The average power output of new offshore turbines is projected to rise to 15 MW by 2030.

Infographic: Global Offshore Wind Expansion by 2030

This infographic highlights the dramatic growth in offshore wind capacity and turbine efficiency expected by the end of the decade.

Conclusion

The Big Bubble Curtain is more than just a technical solution—it symbolizes a responsible approach to marine conservation in the era of renewable energy. As offshore wind becomes a cornerstone of global decarbonization, technologies like the BBC ensure that climate action and biodiversity protection go hand in hand.