During installation of monopiles and jackets at sea the noise generated by high energy pilling may harm the marine environment. There are different methods to reduce these noise levels. One of these mitigation methods is the use of bubble curtains. These bubble curtains are generated by using a loop hose on the seabed, pressurized by air compressors on a support vessel, enclosing the pile driving location. The current practice of bubble curtains is mainly based on experience within previous projects with a limited number of companies offering this service. Due to the lack of understanding of the working principles and practical application there are large variations in the performance of the application of the bubble curtains. For offshore contractors and (renewable) energy companies a better understanding would enable better engineering of bubble curtains, leading to reduced costs of the curtains and reduced sound levels for the local environment.
Fundamental knowledge of the working mechanisms of the bubble curtains is limited which hinders optimisation. Optimisation is, however, necessary to increase the efficiency of the bubble curtains and for example reduce the number of compressors and/or fuel use (and consequently reduce the CO2 footprint).
As a part of the ‘Paris Convention’ many new wind turbines will be installed in the North Sea and around the world. More efficient and effective use of bubble curtains is important to reduce the throughput time, cost, environmental impact and moreover the influence on the marine life. To achieve this MARIN initiates the Bubbles Joint Industry Project.
BUDGET, PLANNING AND PARTNERS
The total secured budget for the bubbles JIP is 1.2 million Euro.The JIP started Q2 2020 and will have a duration of 2 years. The work plan consist of 8 work packages. The findings of the Bubbles JIP will be summarised in a 'Best practice' reference document.
Participating parties are Boskalis, Heerema, Wageningen University and Research, TNO, TU Delft, Seaway Heavy Lifting, IHC, Van Oord, GROW and MARIN.