Factors Affecting Photovoltaic Power Generation

The annual power generation of distributed PV power stations is affected by a variety of factors, resulting in reasonable fluctuations. This is normal and should not be a cause for excessive concern. Just as crop yields are affected by climate, PV power generation also varies with external conditions. There are four main categories of influencing factors, each directly related to power generation.

The first and most crucial category is the climate conditions of the installation site. PV power generation relies on sunlight; therefore, the intensity of sunlight, temperature, rainfall, and cloud cover at the installation site directly affect power generation efficiency. Areas with ample sunshine, little cloud cover, and low rainfall naturally generate more power; conversely, areas with frequent rain and heavy cloud cover will have relatively lower power generation.

In areas with good sunlight conditions, the annual utilization hours of the PV system are approximately 1100 to 1300 hours, resulting in stable and relatively high power generation. In areas with insufficient sunlight and heavy rainfall, the annual utilization hours will be lower, and power generation will decrease accordingly. In addition, excessively high or low temperatures can also slightly affect the module's power generation efficiency, leading to minor fluctuations in power generation. The second category of influencing factors is equipment performance and system design. The type, quality, and installation angle of photovoltaic modules directly determine power generation efficiency: high-efficiency modules generate more electricity under the same sunlight conditions; while the installation angle affects the angle at which the modules receive sunlight, reducing light absorption and power generation.

Simultaneously, the overall design of the PV system is also crucial. For example, the selection of the solar inverter and the configuration of battery storage both affect the overall power generation performance. A reasonable design maximizes the utilization of solar resources, reduces power loss, and makes power generation more stable.

The third category of influencing factors is the product quality of the PV system. A reliable and stable PV system reduces equipment downtime, improves system utilization, and thus increases power generation. Core products include PV modules and inverters. High-quality products operate more stably, have a low failure rate, and maintain stable power generation efficiency over a long period; conversely, poor-quality products are prone to failure, affecting power generation and even shortening the system's lifespan.

The fourth category of influencing factors is daily operation and maintenance. The cleanliness of the PV modules and the system's inspection and maintenance also have a significant impact on power generation. Dust and dirt accumulation on the surface of photovoltaic modules can block sunlight and reduce power generation efficiency, thus requiring regular cleaning. Simultaneously, regular system inspections to promptly identify and address any abnormalities in the wiring and equipment can reduce the failure rate, ensure stable system operation, and guarantee power generation.

It is true that PV modules will experience performance degradation over time; this is a normal characteristic of PV modules, just like the slight performance decline of household appliances over time.

Generally, the degradation rate of PV modules in the first year is about 2.5%, and the annual degradation rate thereafter is typically between 0.5% and 1%, a very slow rate. Furthermore, the degradation rate is affected by module quality and the usage environment: higher quality modules degrade more slowly; harsher environments (such as windy, sandy, or acid rain environments) may result in slightly faster degradation, but overall, this will not significantly impact long-term use.