How to Select Photovoltaic Mounting Systems?

Although the cost of photovoltaic (PV) mounting systems accounts for only a small percentage—just a few percent—of the total cost of a PV power generation system, their selection is crucial. One of the primary considerations is weather resistance. Throughout their 25-year lifespan, PV mounting systems must ensure structural integrity and reliability, capable of withstanding environmental corrosion, wind loads, and snow loads. Installation safety and reliability are also important, aiming to achieve optimal performance with minimal installation costs. Additionally, factors such as whether the system requires minimal maintenance, the availability of reliable repair guarantees, and recyclability at the end of the system's lifecycle are significant considerations.

When designing and constructing PV power plants, the choice among fixed-tilt mounting systems, adjustable-tilt mounting systems, and automatic tracking mounting systems must be made based on local conditions and a comprehensive evaluation of their respective advantages and disadvantages. Each approach has its own merits and challenges, and all are continually being explored and refined. The characteristics of different types of PV mounting systems are as follows:

1. Fixed-Tilt Mounting Systems
   Fixed-tilt mounting systems are commonly used in most scenarios due to their simple installation, low cost, and high safety, as they can withstand high wind speeds and seismic conditions. These systems require almost no maintenance throughout their lifespan, resulting in low operational and maintenance costs. However, their drawback is relatively lower power output when used in high-latitude regions.

2. Adjustable-Tilt Mounting Systems
   Compared to fixed mounting systems, adjustable-tilt mounting systems divide the year into several time periods, allowing the array to achieve an average optimal tilt angle in each period. This approach enhances the annual solar radiation capture compared to fixed systems, potentially increasing power generation by approximately 5%. Compared to automatic tracking systems, which are often associated with technological immaturity, high investment costs, high failure rates, and elevated operational and maintenance expenses, adjustable-tilt systems offer clear advantages. They represent a practical and economically valuable solution.

3. Single-Axis Tracking Mounting Systems
   Single-axis tracking mounting systems deliver superior performance in terms of power generation. Compared to fixed mounting systems, horizontal single-axis systems can increase power generation by 20% to 25% in low-latitude regions and by 12% to 15% in other regions. Tilted single-axis systems can enhance power generation by 20% to 30% across different regions.