Balance Of System (B Definition

What is Balance Of System (BOS)?

Balance of System (BOS) refers to all the components and equipment required for a solar panel installation, excluding the solar panels themselves. It includes items such as the mounting systems, inverters, electrical wiring and protection devices, monitoring systems, and other ancillary equipment.

While solar panels are undoubtedly the most visible part of a solar panel array, the BOS components are critical to enabling the panels to work effectively and safely.

Mounting systems are used to secure the solar panels to a surface or structure, and must be designed with durability and load-bearing capacity in mind. Inverters are essential for converting the DC electrical energy produced by the panels into AC energy for use in homes and businesses. Electrical wiring, fuses, and disconnects are needed to connect the solar panels to the inverter and the electrical grid safely. Monitoring systems help track the performance of the solar panels, providing useful data on power output, energy consumption, and other important metrics.

Other key components of a BOS installation may include batteries for energy storage, charge controllers for regulating current flow from the solar panels, transformers for stepping up or down the voltage, and other devices that ensure the safe and efficient operation of the system.

A properly designed and installed BOS is critical to ensuring that a solar panel array delivers reliable and efficient power. Properly selecting, sizing, and integrating these components is key to maximizing the performance and longevity of a solar panel system.

Why is Balance Of System (BOS) important in solar installation?

Balance of System (BOS) refers to all the components of a solar PV system that are installed besides the solar panels themselves. This includes components such as inverters, battery systems, mounting structures, wiring, and other electrical and mechanical parts. While solar panels are the most visible part of a solar system, BOS components are just as important and play a vital role in ensuring the efficient and safe operation of a solar installation.

BOS components serve several critical functions in a solar power system. Inverters, for example, are responsible for converting the direct current (DC) electricity generated by the solar panels into usable alternating current (AC) electricity that can be used by appliances and devices. Mounting systems secure the solar panels to the roof or other support structure and ensure they are angled properly to capture the maximum amount of sunlight. Wiring and connectors connect the solar panels and other components together and transmit electricity throughout the system.

In addition to their functional importance, BOS components can also significantly impact the performance, efficiency, and lifespan of a solar system. Poorly designed or installed components can lead to decreased energy output, increased installation costs, and potential safety hazards. Choosing high-quality components and working with experienced installers can help optimize the performance and reliability of your solar installation.

Overall, BOS components may not be as eye-catching as solar panels themselves, but they are a crucial part of any solar PV system. By selecting reliable, energy-efficient components and working with experienced professionals, you can ensure the long-term success of your solar installation.

Components of Balance Of System (BOS)

Balance of System, commonly abbreviated as BOS, refers to all the various components and subsystems of a solar panel system, excluding the actual solar panels themselves. A solar energy system consists of several critical components that work together to produce, manage, convert, and distribute electricity. These components are collectively referred to as the Balance of System.

The BOS system comprises different components such as inverters, batteries, charge controllers, mounting structures, monitoring systems, and electrical wiring. These balance-of-system components are responsible for ensuring the efficient and effective functioning of the solar panel system. Each one plays a critical role in the overall performance, durability, and affordability of the solar panels.

The inverter is one of the most important components of the BOS. Solar panels generate DC (direct current) electricity, which must be converted into AC (alternating current) electricity before it can be used by most household appliances. Inverters perform the crucial job of converting DC electrical current produced by solar panels into AC current for everyday use.

Batteries also form part of the BOS system. These energy storage devices store excess solar energy produced during the day so that it can be used during cloudy weather or at night. Battery backups provide uninterrupted power supply during power outages.

The charge controller is another essential BOS component, which regulates the voltage and current flows between solar panels, batteries, and inverters. It ensures that batteries are charged efficiently and safely and can prolong the lifespan of the battery system.

Mounting structures are designed to securely install solar panels on the rooftop, ground or commercial scale for maximum efficiency in generating solar power.

Monitoring systems are responsible for keeping track of the solar panel system’s performance, providing valuable information such as energy production, and identifying any potential issues that could compromise the system’s performance or efficiency.

Lastly, proper electrical wiring and grounding are essential BOS components that ensure safe and efficient electricity distribution to the residence or commercial business.

In conclusion, Balance of System components play a critical role in maximizing the efficiency, output and durability of solar energy systems. Understanding the various Balance of System components and choosing the correct system components will lead to a more efficient and cost-effective solar energy system.



Inverter is an essential component of a solar power system that helps to convert the DC (direct current) electricity produced by the solar panels into AC (alternating current) electricity that can be used by your home or business.

The inverter is responsible for ensuring that the electricity produced by the solar panels is in sync with the electricity grid. This process is crucial as the electricity produced by the panels is not of the same voltage and frequency as the grid, therefore an inverter is needed to convert it into usable electricity.

There are two types of inverters that are commonly used in a solar power system: string inverters and micro-inverters. A string inverter is connected to a set of solar panels, whereas a micro-inverter is connected to each of the individual solar panels.

Inverters come in different sizes and output capacities, therefore selecting the right inverter is very important depending on the power output of the solar panels. It is always recommended to get an inverter that is of the same or higher output capacity as the solar panels to ensure maximum efficiency.

It’s important to have your inverter installed by a qualified and licensed professional, to ensure it is installed safely and performs properly. An improperly installed inverter can result in decreased efficiency and in some cases can cause damage to your solar panels or your electrical system.

Overall, an inverter plays a critical role in converting the DC electricity produced by the solar panels into AC electricity that can be used by your home or business, and it is important to select the right size and get it installed properly by a licensed professional.

Monitoring and Control System

A Monitoring and Control System is an important component of a solar panel installation’s Balance of System. It is used to monitor the performance of the solar panel system and control certain aspects of its operation, ensuring optimum efficiency and safety.

The Monitoring and Control System is responsible for measuring the panel’s electricity output and monitoring the consumption of the connected load. The measurements are displayed on a graphical user interface that is accessible both on-site and remotely, allowing for real-time monitoring of the system’s performance.

One of the essential functions of a monitoring and control system is to ensure that the panels are operating at their highest efficiency possible. When panels are not working efficiently, this will cause energy loss and therefore loss of money. By monitoring the panel’s output and adjusting as necessary, problems can be detected and corrected, ensuring that the maximum amount of energy is being harvested from the system.

The monitoring and control system also helps to keep the system safe. For example, if panels start to overheat or a malfunction occurs, the system will detect this and either shut down or send an alert to the relevant technician who can then take appropriate action.

Overall, a monitoring and control system plays a vital role in ensuring that a solar panel installation continues to operate safely and efficiently, maximizing the return on investment for the system’s owner. It helps mitigate risk and can save money on detecting faults and down time, while ensuring that clean energy is being produced without any harm to people or property.

Battery Storage System

A battery storage system is an essential part of the Balance of System (BoS) for solar panel installations, especially for those looking to optimize their energy production and consumption.

A battery storage system stores excess energy generated by solar panels during the day, which can then be used during peak electricity demand hours or at night when no solar energy is being generated. The battery bank reduces dependence on the utility grid, increases self-consumption, and minimizes energy wastage by taking advantage of the excess energy generated during the day.

Installing a battery storage system as part of the BoS requires careful consideration of the type of batteries required, their capacity, and their placement. Most battery storage systems used in solar installations are lithium-ion batteries, although there are other options available.

It’s important to note that battery storage systems can be a significant investment, and their cost needs to be factored into the overall cost of the solar panel installation. However, the long-term benefits can outweigh the initial cost, including reducing energy bills, providing backup power during outages, and utilizing clean, renewable energy sources.

Overall, a battery storage system is a critical component of the BoS for any solar panel installation looking to maximize energy production and consumption while reducing dependence on traditional energy sources.

Metering Equipment

Metering Equipment is a crucial part of a solar panel installation’s balance of system. It refers to measuring the electricity generated by your solar panels and how much of it is being used or sent back to the grid. This equipment provides accurate data on your energy consumption and production, making it possible to monitor and optimize the system’s performance.

There are several types of metering equipment used in solar panel installations. The first is a production meter, which monitors the amount of electricity generated by the solar panels. It is usually installed between the inverter and the utility meter. The production meter tracks how much power the solar panels produce and sends this data to the utility and to the system owner.

Another type of metering equipment is a consumption meter, which tracks how much electricity the property is consuming. This meter is installed near the main electrical panel and measures the amount of electricity being used by appliances and electronics inside the building. The consumption meter allows the system owner to see how much energy is being used and when, enabling them to manage their electric usage and potentially save on energy bills.

In addition to production and consumption meters, some installations require a bidirectional meter. A bidirectional meter measures both the electricity produced by the solar panels and the electricity consumed by the building. This type of meter is necessary when energy is sold back to the grid, as it measures the excess electricity produced and sent back to the utility.

In summary, metering equipment is a vital component of a solar panel installation’s balance of system. It provides the data needed to optimize performance and ensure that the system is functioning correctly. By tracking electricity production and consumption, metering equipment helps the system owner manage their energy use and potentially lower their electricity bills.


Mounting is an important aspect of the Balance of System (BOS) when it comes to solar panel installation. It refers to the physical structures used to fix solar panels on a rooftop, ground or any surface. The mountings should be secure enough to hold the solar panels in place for several years, tolerating different weather conditions.

There are several types of solar panel mountings, each designed to cater to specific installation requirements. The most common ones include roof mount, ground mount, and pole mount. The roof mount is the most common type of mounting where the panels are attached directly to the roof’s rafters or trusses. Ground mounts are used for installation purposes in large commercial installations, while pole mounts are commonly used in small installations.

When choosing a mounting system, it is important to ensure that it is compatible with the type of solar panels you are installing. The mounting systems should also be appropriately sized and engineered based on the location of the installation, to ensure maximum safety and efficiency.

Importantly, a qualified installer should always perform any mounting work to ensure the safety of the system, structures, and people. They should also be able to follow the recommendations included in the installation manual provided by the manufacturer of the mounting hardware.

Overall, selecting the right type and quality of mounting plays a critical role in the overall performance of your solar panel system. A properly installed mounting is essential to the long-term durability of the system, ensuring it’s able to withstand any environmental challenges, and maximizing the efficiency of the solar panel system.

Wiring and Protection

Wiring and Protection is an essential component in the installation of a solar electric system. It is the electrical connection between the solar panels and the inverter, which ultimately converts the DC power generated by the solar panels to AC power that is usable by your home or business. The wires must be of high quality and resistant to outdoor conditions such as rain and UV rays to avoid damage to the system.

The wiring system should be designed in a way that reduces the amount of power loss that occurs between the solar panels and the inverter. This can be achieved by using the correct wire gauge, which is determined by the distance from the panels to the inverter and the amount of power being produced. A larger wire diameter is recommended for larger systems or long distances, as it can carry more current with less energy loss.

In addition to the wires, there are other vital components that ensure the system is protected and efficient. For example, surge and lightning protection devices prevent damage to the system in case of a voltage spike in the electrical grid. A ground fault protection device precisely detects current irregularities that could cause electric shock and provides a quick tripping action to prevent electrical hazards.

It is also necessary to select and install circuit breakers, disconnect switches, and fuses to disconnect power on demand from the system during maintenance works, repairs, or emergencies. Such protective devices provide a quick means of isolating the solar panels from one another or from the inverter as and when needed.

Overall, wiring and protection are intricate components require professionals who are familiar with regulations governing power generation systems, to ensure that all components meet strict codes, and that the installed solar panel system is safe and operates smoothly.


Knowing about Balance Of System (BOS) is crucial if you want to be successful in running a solar company. BOS refers to components and equipment necessary to complete a solar panel installation, excluding the solar panels themselves. Although solar panels are the most visible part of a solar array, the BOS components play a fundamental role in ensuring that the panels function correctly and reliably.

Mounting systems, inverters, electrical components, monitoring systems, and other ancillary equipment are all parts of the BOS. Mounting systems should be strong enough to hold the solar panels securely to a surface or structure. Inverters convert the DC electrical energy generated by the solar panels into AC energy for use in homes and businesses. Electrical wiring and protection devices connect the solar panels to the inverter and the electrical grid safely. Monitoring systems keep the solar panels running at maximum capacity and alert the system owner if any malfunctions occur.

In summary, understanding BOS and its components is critical to building a successful solar company. A well-designed and well-built BOS guarantees that panels operate effectively and safely while meeting customer expectations. Taking the time to comprehend the components of a solar array and how they operate together will result in a more efficient solar panel installation process, increased customer satisfaction, and greater potential for new business.