Photovoltaic (PV) racking systems are structural devices used in solar photovoltaic power generation systems to securely fix and support PV modules. Their primary function is to ensure that the modules receive sunlight at the optimal angle, thereby maximizing power-generation efficiency while maintaining stable operation under various environmental conditions. Below is an overview of their structural components, types, core functions, and key features:

Structural Components

Photovoltaic mounting systems typically consist of the following key components:

Supporting structure: It includes the main framework components such as columns, beams, and diagonal braces, which support the weight of the photovoltaic modules and transfer the loads to the foundation.
Connector: Such as bolts, fixtures, guide rails, etc., which are used to securely connect the various structural components and photovoltaic modules, ensuring overall stability.
Basic components: Depending on the installation scenario, the mounting system can be secured to the ground, rooftop, or other surfaces using concrete foundations, helical piles, counterweight blocks, or similar methods, ensuring stability against external forces such as wind, snow, and earthquakes.

Main types

Based on the installation scenario and adjustment method, photovoltaic mounting systems can be classified into the following categories:

Classified by installation location

Ground-mounted racks: Installed on open ground, ideal for large-scale photovoltaic power plants. They can be adjusted in height to accommodate various terrains (such as flat or sloped land), and come in diverse foundation types (e.g., concrete, helical piles, etc.).
Roof brackets: Installed on building roofs (flat or pitched), these brackets must account for roof load-bearing capacity and waterproofing. They feature a relatively lightweight structure and commonly come in designs such as flat-mounted or diagonally installed types.
Special-purpose mounting structures: such as water-surface mounts (floating on reservoirs, fish ponds, and other water bodies), BIPV (Building-Integrated Photovoltaic) mounts (integrated with building structures, serving as support systems for photovoltaic curtain walls or photovoltaic tiles), and more.

By angle-adjusting capability

Fixed支架: After installation, the angle remains fixed. The tilt angle is preset based on local latitude and sunlight conditions. This design is simple, cost-effective, and ideal for areas with stable lighting conditions.
Adjustable支架: These can be manually or electrically adjusted for angle, such as seasonal adjustments (to accommodate changes in the sun's altitude throughout different seasons) or tracking adjustments (which use sensors and drive mechanisms to keep the modules continuously aligned with the sun's path). While this significantly boosts power generation, it comes with higher costs and increased maintenance requirements.

Core Functions and Design Requirements

Ensure photovoltaic modules receive maximum sunlight: Optimize the tilt angle and orientation (typically facing south in the Northern Hemisphere) to maximize solar radiation absorption and minimize shading effects—such as avoiding shadows cast by trees or buildings.
Load-bearing and wind/earthquake resistance: The structure must withstand the self-weight of photovoltaic modules, as well as wind and snow loads, seismic forces, and more. During design, it’s essential to consider local meteorological and geological conditions to ensure both structural strength and stability.
Weather Resistance: The bracket material must possess corrosion-resistant and anti-aging properties (e.g., using hot-dip galvanized steel, aluminum alloy, etc.) to withstand long-term outdoor use (with a lifespan typically matching that of the photovoltaic system—around 20 to 25 years).

Material Characteristics

Steel materials: Commonly used options include hot-dip galvanized angle steel and channel steel, which offer high strength and moderate costs. They are ideal for large-scale ground-mounted support systems, but proper anti-corrosion treatment is essential.
Aluminum alloy: Lightweight and highly corrosion-resistant, making it ideal for rooftop brackets or applications where weight is a critical factor. However, it comes at a higher cost and has slightly lower strength compared to steel.
Other materials: Some small brackets may be made of stainless steel (corrosion-resistant but costly) or composite materials (such as glass fiber-reinforced plastic—lightweight, but strength needs to be verified).

Importance

Although photovoltaic (PV) mounting structures don’t directly participate in the conversion of solar energy into electricity, they serve as the "skeleton" of the PV system—so their design quality directly affects both power generation efficiency and the system’s lifespan. For instance, tracking-mounted structures can boost power output by 10% to 30% compared to fixed-mount systems. Conversely, poor-quality or improperly designed mounts may fail under load, leading to module detachment or deformation, which not only poses safety risks but also results in significant energy losses.

In summary, photovoltaic mounting structures are an indispensable component of photovoltaic power generation systems. Their selection and design must comprehensively consider various factors such as environmental conditions, cost, and efficiency, ensuring the safe operation of the PV system.