Engineering Noise reduction for Hydroelectric power plant

Steps that can be taken to help mitigate excessive noise in the hydroelectricity industries

Since the amount of machinery, such as turbines, air compressors, and rotors associated with each generating unit, noise production in Hydroelectric power plants is high.


The human body has few resources to defend itself from noise. This alteration can create many effects on the human organism including contemporary stress that changes working behavior, produces low productivity, high rates of absences from work and obviously hearing loss.

Hydroelectric Power Plants generate lots of power and sometimes excessive noise. Among hydropower plants, there are some built more than half a century ago, and the noise was not factored into plant design. To confirm that, most power plants have hard concrete walls that magnify sound. What happens is that energy doesn’t go anywhere, it just bounces off the walls. And that tends to increase the noise levels even way above the source.

To capture the noise profile and target even the subtlest reverberations, Soundproofing experts must perform acoustic surveys using cutting-edge analytical equipment to isolate hazardous noise sources.


“In marine vessels and submarines stationed across the globe, noise suppression technologies have been successfully used in engine rooms since the 1970s. They’ve put a lot of effort into making sure that a marine vessel is very quiet, so their engine rooms are really similar to a hydropower plant, with thick walls, and water all around. There may be a connection, relationship there and sure enough, it was. So, choosing a partner with strong expertise in the marine sector will help to solve noise concerns in these peculiar power plants.” LEARN MORE

Soundproofing Hydroelectric Plant

To mitigate noise, soundproofing experts must analyze and design solutions for treating the noise at the source (if possible), but, due to plant complexity, frequently the plan involves treating the transmission path to the receiver.

While designing soundproofing solutions, maintenance considerations must be taken into account in suggesting noise control techniques for hydroelectric power plants. Materials and methods need to be as maintenance-free as possible and still able to achieve the desired noise reduction level. Used materials also need to meet safety regulations for fire, smoke, and toxicity.

Here are some examples of soundproofing solutions for Hydroelectric stations:

  • Damping

Damping is a term used to describe applying a viscoelastic material to a structure to reduce the vibration of that structure. Since noise (acoustical energy) can be generated by a structure that vibrates and is an efficient radiator, reducing the surface velocity due to damping will also reduce noise.

  • Sound Absorption

Silencers are the most well-known example for absorbing energy to reduce noise. By adjusting the specifications of the silencers, acoustical energy at certain frequencies will be “trapped” within the silencer body and will dissipate.

  • Acoustic Barriers

The concept behind an acoustic barrier is simple. By placing a solid wall (barrier) between the sound source and the receiver, the acoustical energy gets reflected back to the source and will not reach the receiver, thus reducing overall noise. Acoustic enclosures and barriers are ideal for spaces where frequent access is required, yet a significant reduction in the transmission of acoustical energy is desired, such as a turbine pit.


Included in the supply are the previous surveys, the design, the construction, the installation, and the photometric measurements of an acoustic booth…(READ MORE)


Because of the variety of contributing noise sources in Hydroelectric plants, there is no one-size-fits-all solution. Due to the complexity of the acoustical challenges this sector faces, a tailored solution is required to ensure the deployment of effective noise control systems.

Following an initial consultation path with a leading industrial and environmental noise control manufacturer, is the quickest and most effective way to solve complex noise mitigation challenges.

Stopson Italiana has worked internationally with plant processing engineers and their consulting teams to provide accurate and cost-efficient, site-wide noise assessments and mitigation solutions of industrial sectors such as petrochemical complexes both large and small.


Enel Green Power soundproofs the Generation Group No. 3 of hydroelectric power plant in Bordogna with Stopson Italiana’s Acoustic Enclosures

Included in the supply are the ante-operam surveys, the design, the construction, the installation and the phonometric measurements of an acoustic booth, for the historic plant in Moio de Calvi, val Brembana.


The soundproofing intervention consisting of an acoustic enclosure for the Enel Green Power plant in Bordogna has recently been completed.

The acoustic cabin was designed to be installed inside the beautiful power plant built in 1932 which, exploiting a useful jump of 546.55 meters and a maximum derivable flow of 12 square meters/sec through two forced pipes that feed 3 hydraulic turbines Pelton is in able to provide efficient power of around 47,000 KW.

Acoustic Enclosure, Bordogna Hydroelectric Plant (Italy)

With a size of 11.6 x 11.1 x 3.8 m, the structure has been made accessible and completely removable by means of a bridge crane in its upper part, in order to facilitate the management of the turbine components.

The air outlet from the system has been designed using an electric fan, which, when coupled to a silencer, expels air outside the plant through an opening located on the central window.

The soundproof cabin was designed to guarantee an average residual sound pressure level of 78 dB (A), measured at 1 m from the cabin and 1.7 m from the floor.

Stopson Italiana acoustic enclosures are modeled around every type of noisy equipment, internal or external, on skid and on the ground. They are designed to provide excellent attenuation of sound emissions in any critical environment. The realization takes place in modular acoustic panels and coatings for noise insulation, guaranteeing at the same time the maintenance of the equipment, ventilation, weather protection and fire safety.


The typical applications of acoustic enclosures are:

  • Energy production systems, including gas turbine steam turbines, traditional and industrial recovery boilers, diesel generators;
  • Cogeneration plants (CHP);
  • Natural gas compression networks and facilities;
  • Manufacturing and process industry: for example the automotive industry, paper industries, printing houses, etc.


⟶ More information about Stopson Italiana Acoustic Enclosures here.