Greenov conducts tests at sea for the SubSea Quieter®, our underwater noise reduction system

News | 5 March 2024

GREENOV, a mission-driven company housed in the Incubator Central Nantes, has initiated the first sea trial of the SubSea Quieter®, a disruptive noise mitigation system based on an innovative membrane designed to mitigate the impact of maritime activities on underwater ecosystems. With six years dedicated to its development, the SubSea Quieter® offers a unique solution for coastal and offshore companies to minimize their environmental footprint.

The initial prototype, tailored for 2.5-meter diameter piles, will undergo extensive real-world testing for two months starting in early 2024. These trials aim to validate the acoustic performance and user-friendliness of the future full-scale system.

Reducing underwater noise: a priority to protect our oceans

Underwater noise reduction is a critical priority for safeguarding our oceans. The rapid propagation of sound underwater—four times faster than in the air—makes it imperative to mitigate the disruptive effects of human activities on marine life, which relies heavily on sound for navigation, communication, and feeding.

Pile driving operations used for wind turbines installation generate intense underwater noise, reaching up to 260dB, causing significant disturbances to aquatic fauna. They disrupt the communication of marine animals – through masking – and behavioral changes can be observed. Loud noise can cause temporary or permanent hearing loss. Some particularly intense noises can even lead to the death of animals, for example by causing physical impacts on hearing organs or the bladders of fish to explode. As people build more ports to combat global warming, and as offshore wind farms multiply to decarbonize our energy supply, the sources of underwater noise in our oceans are exploding! Global regulations, particularly in Europe and France, are therefore increasingly stringent in reducing these impacts.

The SubSea Quieter – A disruptive and highly effective solution for reducing underwater noise and turbidity from marine operations

The SubSea Quieter® system is a noise abatement technology which aims to impede the transmission of underwater noise from works operations in the marine environment. It can also contain turbidity generated by coastal works. The SubSea Quieter® system is based on a multi-layer membrane into which a fine particle of air is injected to create a barrier to the sound waves.

Particularly innovative and relatively simple to use, the system reduces noise by 10 to 35 decibels depending on the sound frequencies, i.e., a 94 to 99% reduction in the acoustic power of marine operations, a performance well above that of existing systems such as bubble curtains.

Greenov has developed two types of the SubSea Quieter®:

  • The SubSea Quieter® Blue Shield, which takes the form of a curtain to enclose an extended area corresponding to coastal / port work;
  • The SubSea Quieter® Pile Driving, A set of membrane panels that are attached together to form a double barrier around the pile, and which are then inflated prior to pile driving operations.

The SubSea Quieter® has won several recognitions in France such as Prix Décibels d’or 2024, selected as one of the 30 start-ups in the first French Blue Tech Index 2023, Prix Port du Futur 2022, Prix Du Ministère de la Transition Ecologique, Prix Solar Impulse, etc.; as well as the AMBA Global Start-up of the Year 2022 award and the prestigious European EIC Accelerator program.

A reduced-scale test in the port of Saint-Nazaire in Q1 2024

This is the first time the company will be testing the SubSea Quieter® pile driving system. Testing began in December 2023 with the assembly of the system and an initial validation of the subsystems in air. They will be followed by a series of tests over a 4-week period between February and March 2024 under sea conditions in the Port of Saint-Nazaire (France).

The trials are being carried out in collaboration with Bouygues Travaux Publics Régions France and Quiet-Oceans, two companies providing their expertise in marine civil construction and underwater acoustics.

Entirely designed and manufactured by a network of partners in the Pays de la Loire region, France and Europe, the system is 10m high, 5m in diameter and weighs 25 tones. It is equipped with membrane panels held in place by two metal structures: a high structure equipped with powerful winches that allow the system to slide around the pile to be beaten, and a low structure that functions as a basket into which the membrane is folded before being deployed until the seabed. These trials will also enable the company to invite its network of partners: local authorities, public organizations, manufacturers, suppliers, NGOs and future customers.

The final stretch before market launch and fund-raising

With these tests, Greenov aims to confirm the viability of its system and accelerate its commercialization. Following these trials, Greenov aims to see its SubSea Quieter® become the new standard solution in the underwater noise reduction market, estimated at €350M/year worldwide, and will launch a dedicated subsidiary called SEALENCE in mid-2024, with a strong ambition: to become the world leader in the sector within 5 years!

Greenov will soon be raising €10M to complete its R&D work and expand internationally, with its sights set on the European, North American and Asian markets, and several exciting projects already signed. Directly and with local partners, Greenov aims to create more than 200 jobs.

Let’s forge ahead with determination, passion, and a shared commitment to safeguard the oceans — one innovation at a time.


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