In low-light areas, the power generation efficiency of solar panels is limited, and the system revenue needs to be enhanced through refined maintenance strategies. The following provides practical maintenance solutions for low-light scenarios from five dimensions: component selection, installation optimization, operation monitoring, fault detection, and energy efficiency improvement:
First, the selection of components and equipment should be compatible
Selection of high-sensitivity components
Priority should be given to components with a weak light response coefficient of ≥95%, such as those using high-efficiency battery technologies like PERC, HJT, and TOPCon. This type of component can still maintain a high power generation efficiency when the light intensity is as low as 200W/㎡. For instance, HJT modules generate 10% to 15% more electricity in low light than conventional modules.
Pay attention to the temperature coefficient of the components and select products with a temperature coefficient of ≤-0.3%/℃. Low-light areas are often accompanied by low temperatures. The lower the temperature coefficient, the smaller the power generation loss of the components in a low-temperature environment.
Upgrade of supporting equipment
The inverter needs to have a wide voltage input range (such as 100V-1000V) and MPPT dynamic tracking capability, which can quickly lock the maximum power point when the light fluctuates to avoid power generation loss. It is recommended to select an inverter with multiple MPPTS to deal with the problem of local occlusion.
It is recommended that the energy storage system be equipped with lithium iron phosphate batteries. Their low-temperature performance (discharge efficiency ≥80% at -20℃) and cycle life (> 6,000 times) are superior to those of lead-acid batteries, which can ensure long-term stable operation in low-light areas.
Second, installation and layout optimization
Orientation and inclination adjustment
According to the local solar trajectory data, the optimal inclination Angle for the annual comprehensive power generation is usually 5°-10° larger than the latitude. For example, in the area at 40° north latitude, it is recommended to adopt a 45° inclination Angle.
The orientation of the components should avoid the prevailing wind direction in winter (for example, in northern regions, avoid facing due north) to reduce the accumulation of snow and dust.
Shadow avoidance and arrangement optimization
By using drone aerial photography and 3D modeling technology, the shadow impact of surrounding buildings, trees and other obstructs on the components is analyzed. The spacing between adjacent components must be unobstructed from 9:00 to 15:00 on the Winter solstice. The formula for calculating the spacing is: D = H × cot(α) (where D is the spacing, H is the height of the obstruction, and α is the solar altitude Angle on the local winter solstice).
The “fish-scale” staggered arrangement is adopted to reduce the shadow shading of the front components on the rear, thereby enhancing the overall power generation efficiency.
Third, operation monitoring and data analysis
Real-time data acquisition
Deploy an intelligent monitoring system to collect parameters such as component temperature, irradiance, power generation capacity, and inverter efficiency. The data collection frequency should be no less than once per minute.
Install micro weather stations to monitor real-time irradiance, wind speed, temperature, humidity and other environmental data, providing a benchmark for power generation analysis.
Abnormal diagnosis and early warning
The system efficiency is evaluated through PR (Performance Ratio) analysis, and the PR value should be ≥75%. If the PR value is lower than 70%, issues such as component attenuation, line loss, and inverter failure need to be investigated.
Set up a three-level early warning mechanism: When the irradiance is lower than 100W/㎡ and lasts for 30 minutes, trigger the first-level early warning (to check the operating status of the equipment); When the component temperature is lower than -10℃, a secondary warning is triggered (the heating device is activated). A level three warning (comprehensive maintenance) is triggered when the power generation is 20% lower than the historical average for the same period.
Fourth, troubleshooting and maintenance
Component cleaning and snow removal
Dust accumulation in low-light areas has a significant impact on power generation. It is recommended to clean the components once a month. Adopt waterless cleaning technology (such as silicone squeegee + anti-static brush) to prevent water stains from remaining.
When the snow thickness in winter exceeds 5cm, it should be cleared in time. Flexible snow removal brushes or heating films (power ≤50W/㎡) can be used to assist in snow removal to avoid hard objects scratching the surface of the components.
Maintenance of the electrical system
Inspect the DC side lines once every quarter, with a focus on checking for issues such as cable damage, loose joints, and oxidation corrosion. Use an infrared thermal imager to detect the temperature of the joint. If the temperature exceeds the ambient temperature by 20℃, immediate treatment is required.
Conduct in-depth maintenance on the inverter every year, including internal dust removal, capacitor inspection, and replacement of the cooling fan, etc. Check the inverter efficiency curve. If the efficiency is 5% lower than the nominal value, it needs to be returned to the factory for maintenance.
Fifth, energy efficiency improvement and transformation
Application of optical efficiency enhancement technology
Adding an anti-reflection film to the surface of the component can increase the light transmittance by 3% to 5%. Or use a microprism backsheet to reflect the scattered light back to the solar cells, increasing the power generation by 2% to 3%.
For areas with severe snow accumulation, bifacial modules and highly reflective ground (such as white crushed stones or coatings) can be installed to increase power generation by utilizing the reflected light from the ground.
System expansion and optimization
Based on historical power generation data, calculate the expansion critical point (such as when the PR value of the existing system is greater than 80% and the load gap is greater than 20%). When expanding capacity, high-power components (such as 700W+) and string inverters should be given priority to reduce system costs.
Carry out intelligent transformation of old systems, install power optimizers or intelligent shutters, solve the problem of component mismatch, and increase power generation by 5% to 10%.
Sixth, response to Special scenarios
Moisture-proofing in high-humidity areas
Apply moisture-proof silicone to junction boxes, inverters and other parts to prevent condensation and short circuits.
Install a dehumidification device to keep the internal humidity of the equipment below 60%.
Dust prevention in sandy and windy areas
Set up windbreak and sand barriers (such as windbreak nets and green plants) around the components to reduce the speed of sand and dust deposition.
Self-cleaning coating components are adopted to reduce the frequency of manual cleaning.
