The decline in power generation of photovoltaic (PV) power stations can be caused by various factors. Below are some common reasons and their solutions:
1. Environmental Factors
Weather Conditions:
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Cause: Cloudy days, haze, sandstorms, and other weather conditions can reduce solar radiation, leading to a decrease in power generation.
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Solution: Regularly clean the surface of PV modules to ensure optimal light transmission.
Seasonal Changes:
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Cause: Shorter daylight hours and lower solar angles in winter naturally reduce power generation.
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Solution: Optimize the tilt angle design of PV modules to adapt to the solar angle in different seasons.
2. Equipment Issues
Aging or Damaged PV Modules:
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Cause: Prolonged use or physical damage to modules can reduce efficiency.
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Solution: Regularly inspect the condition of modules and replace aged or damaged ones promptly.
Inverter Failure:
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Cause: Inverters are the core equipment of PV systems, and their failure can significantly reduce power generation.
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Solution: Regularly maintain inverters and repair or replace faulty equipment in a timely manner.
Cable or Connector Problems:
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Cause: Aging cables, loose or corroded connectors can increase power transmission losses.
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Solution: Inspect cables and connectors to ensure they are intact and functioning properly.
3. Dust and Dirt
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Cause: Accumulation of dust, bird droppings, leaves, and other debris on the surface of PV modules can block sunlight and reduce efficiency.
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Solution: Regularly clean the surface of PV modules, especially in dusty areas.
4. Shading
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Cause: Shadows from buildings, trees, poles, or other objects can partially or completely reduce the efficiency of PV modules.
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Solution:
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Avoid shading during the design phase.
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Use modules with bypass diodes to minimize the impact of shading on the overall system.
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5. System Design Issues
Mismatched Modules:
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Cause: Mixing modules of different models or batches can lead to reduced system efficiency.
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Solution: Ensure all modules have consistent parameters and avoid mixing.
Improper Tilt and Azimuth Angles:
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Cause: Incorrect tilt and azimuth angles of PV modules can affect solar radiation reception.
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Solution: Optimize the design based on local latitude, longitude, and solar trajectory.
6. Grid Issues
Grid Voltage Fluctuations:
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Cause: High or low grid voltage can cause inverters to shut down or operate at reduced capacity.
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Solution: Check grid voltage and communicate with the grid company if necessary.
Power Limitation Policies:
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Cause: Some regions may implement power limitation policies due to grid load constraints.
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Solution: Understand local policies and plan power generation accordingly.
7. Temperature Effects
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Cause: The efficiency of PV modules decreases as temperature rises (temperature coefficient effect).
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Solution:
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Choose modules with a lower temperature coefficient.
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Ensure proper ventilation to avoid overheating.
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8. Inadequate Operation and Maintenance (O&M)
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Cause: Lack of regular maintenance and monitoring can lead to undetected and unresolved issues.
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Solution:
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Establish a comprehensive O&M management system.
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Use monitoring systems to track power generation in real-time and identify anomalies promptly.
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9. Animal Activity
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Cause: Birds, rodents, and other animals may nest under PV modules or damage cables.
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Solution: Install protective nets or bird deterrents and regularly inspect cable conditions.
10. Policy or Market Factors
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Cause: Policy adjustments or market changes in some regions (e.g., reduced subsidies, electricity price adjustments) may lead to decreased power generation.
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Solution: Stay informed about policy changes and optimize power station operation strategies.
Conclusion
The decline in power generation of PV power stations can result from a combination of environmental, equipment, design, and O&M factors. Regular inspections, maintenance, and system design optimization can effectively improve power generation efficiency and ensure the long-term stable operation of the power station. If power generation continues to decline and the cause cannot be identified, it is recommended to contact a professional PV O&M team for a detailed investigation.