When photovoltaic panels absorb sunlight under the glow, when wind turbine blades spin to generate electricity in the wind, and when rushing water stores energy to generate power, most of these clean energy sources rely on the "power granary"—energy storage systems—for storage and distribution.But did you know that this great contributor to energy stability can sometimes become a "noise source"?From the hum inside containers and the vibration from equipment operation to the wind noise of energy storage systems, such noise not only affects the surrounding environment but may also shorten the service life of equipment.Today, NCC is uncovering the mystery of energy storage noise reduction to show how technology enables energy storage systems to "work quietly".

First, Understand: Where Does Energy Storage Noise Come From?

Mechanical Noise

This is the primary noise source of energy storage systems. When equipment such as power conversion systems (PCS), cooling fans of large liquid cooling units, and water pumps are in operation, the rotation of internal bearings, blade air cutting, and friction of mechanical components all generate vibrations, which are then converted into audible noise. With a frequency range of 200-2000Hz, it sounds particularly harsh, with a sound pressure level of 85dB (A).

Aerodynamic Noise

To maintain a suitable operating temperature for batteries, energy storage systems are equipped with large liquid cooling units and water chillers. Axial or centrifugal fans are commonly used to ensure heat dissipation of energy storage equipment. Turbulence and eddy currents generated by high-speed fan operation, as well as airflow impact at the fan inlets and outlets, all produce aerodynamic noise. This type of noise has a wide propagation range and slow attenuation speed, with a sound pressure level of 80dB (A).

Electromagnetic Noise

When electric current passes through the coils and iron cores of energy storage equipment, electromagnetic force is generated, causing iron core vibration. This vibration is transmitted to the equipment housing and forms noise. Especially at the moment of charge-discharge switching in energy storage systems, the electromagnetic force changes drastically, leading to a sudden increase in noise.

Core Principles: The Three "Magic Weapons" of Noise Reduction

Energy storage noise reduction is not a one-size-fits-all sound insulation solution. Instead, it combines the three core principles of "absorption, insulation, and silencing" based on different noise types and propagation paths, achieving noise reduction goals from three dimensions: source control, process blocking, and end weakening.

Magic Weapon 1: Sound Absorption – Let Noise "Be Absorbed"

The sound absorption principle is mainly targeted at air-borne noise. By using porous and loose sound-absorbing materials (such as glass wool, polyester fiber cotton, rock wool, or foam aluminum), noise sound waves enter the pores inside the materials.As sound waves propagate through the pores, they rub against the pore walls, and the mechanical energy of the sound waves is converted into thermal energy and dissipated, thereby achieving noise attenuation.

Based on this principle, NCC has researched, developed and provided matching standard Acoustic  louvers and ventilation Acoustic Enclosure products (QUIET 10 model), which can effectively reduce high-frequency noise generated by cooling fans. Without affecting equipment ventilation and heat dissipation, cooling capacity output and energy consumption, the noise can be reduced by 10-15dB after sound absorption treatment—equivalent to reducing the noise of a busy street to that of a quiet office.

Magic Weapon 2: Sound Insulation – Set a "Barrier" for Noise

If sound absorption is "internal consumption", sound insulation is "external blocking".The sound insulation principle utilizes the reflection and attenuation characteristics of sound waves when propagating through different media. By installing dense and heavy sound insulation structures (such as Aoustic wall Panels, Acoustic barriers), noise transmission from the noise source to the surrounding environment is prevented.

For high-noise equipment such as power conversion systems (PCS), a common practice is to customize NCC Aoustic wall Panels for them, with two models NVT50 and NVT100 available. The panel adopts a double-layer steel plate structure, with a sound absorption layer on the inner side, a sound insulation layer on the outer side, and damping materials filled in the middle. It can not only block noise from spreading outward but also suppress the vibration of the equipment itself.The sound-absorbing and insulating walls at the boundary of energy storage stations can reduce the 70-80dB noise of the station to below 50dB outdoors, meeting the European, American and international environmental noise standards for residential areas.

Magic Weapon 3: Acoustic – Let Noise "Attenuate on the Way"

Acoustic is mainly targeted at aerodynamic noise, with the core being the installation of Acoustic on the noise propagation path.Through internal structures such as perforated pipes, resonance chambers, and expansion chambers, silencers make sound waves reflect, interfere and diffuse during propagation, thus gradually attenuating the noise.According to different noise types, Acoustic can be divided into reactive Acoustic, resistive Acoustic and composite Acoustic.

For example, in the ventilation ducts of energy storage systems, NCC resistive Acoustic (model NCC-MS) are installed at the fan inlets and outlets to absorb airflow noise by using sound-absorbing materials; for low-frequency airflow noise in the ducts, reactive Acoustic are adopted to offset noise through the resonance effect of resonance chambers.The NCC Acoustic system can reduce the noise of ventilation ducts by 20-30dB, completely solving the problem of "the fan roars, the whole city hears it".

Practical Solutions: Combined Noise Reduction "Tactics" for Different Scenarios

Energy storage systems are applied in a variety of scenarios, from large-scale centralized energy storage power stations to distributed household energy storage, with different noise reduction needs. Therefore, it is necessary to match the "absorption, insulation, silencing" solutions in a targeted manner.

Centralized Energy Storage Power Stations

Such power stations feature concentrated equipment and high noise intensity, and usually adopt a combined solution of "NCC ventilation and Acoustic Enclosure + NCC Acoustic louver".Core noise-generating equipment such as PCS and transformers are enclosed in Acoustic Enclosure, the ventilation system is equipped with composite Acoustic, and sound insulation barriers are installed around the power station to form an all-round noise reduction system.

Distributed Energy Storage (e.g., Industrial, Commercial and Household)

Such energy storage equipment is small in size and close to crowds, with greater emphasis on "lightweight" noise reduction.Low-noise fans can be used to replace traditional fans, the equipment housing is coated with damping materials to suppress vibration, and small NCC Acoustic louvers are matched. This solution can not only meet noise reduction requirements but also satisfy the aesthetic needs of appearance.

Outdoor Containerized Energy Storage

Containers themselves have a certain sound insulation effect. On this basis, sound-absorbing materials can be pasted on the inner walls of containers, and shock absorption pads can be installed between the equipment and the container base to reduce vibration transmission.At the same time, NCC ventilation and Acoustic Enclosure  NCC Acoustic  are optimally matched to achieve the dual protection of "passive sound insulation + active silencing".

Future Trends: The "Mutual Pursuit" of Noise Reduction and Energy Efficiency

With the rapid development of the energy storage industry, NCC Boheng's noise reduction technology no longer takes "single noise reduction" as the goal but is deeply integrated with equipment energy efficiency and cost control.NCC  independently developed new patented technology—"Active Noise Reduction Technology: A Method for Noise Sensing and Suppression of Energy Storage Equipment"—has been applied in the energy storage field. By collecting noise signals through sensors and then emitting sound waves with opposite frequencies to the noise through speakers, it achieves "active cancellation" of noise. This technology has a particularly significant effect on low-frequency vibration noise and does not affect equipment heat dissipation.

At the same time, NCC Boheng's independently developed "Intelligent Control Ventilation and Energy-Saving Acoustic Shutter Based on Cloud System" can automatically adjust according to the dynamic environmental noise and heat dissipation conditions.To better adapt to the environment, save energy consumption and safeguard a green and healthy future, NCC Boheng's "low-noise design + intelligent noise reduction system" will become a standard configuration for energy storage equipment, making energy storage systems not only a stable "power granary" but also a quiet "energy partner".