How to Maintain a Solar Power System?

 

Maintaining a solar power system is built on a foundation of safety. Regular equipment inspections and scheduled maintenance checks are essential for effective power station management, helping ensure safe and stable operation while maximizing the return on investment.

 

Operation Management of a Solar Power System

The production and operation management of a photovoltaic (PV) power generation system mainly includes work permit management, operation permit management, switching operation management, equipment inspection management, regular equipment changeover and testing management, dispatch management, and defect management.

 

1. Operation Monitoring

PV power stations generally adopt an intelligent operation mode featuring centralized monitoring, unattended operation, and minimal staffing. Operators use the centralized monitoring system to remotely monitor and control the PV power station and analyze faults.

 

Operation monitoring mainly includes monitoring various analog values of PV power generation equipment, such as the voltage and current at the grid-connection point, the AC and DC power of inverters, ambient temperature, and irradiance, as well as various status values, such as the positions of circuit breakers and disconnect switches, protection-device actions and alarm signals, and inverter operating status.

 

 

In addition to PV power generation equipment, the monitoring scope also includes personnel activity within the area where the equipment is located. This is generally achieved through a video surveillance system equipped with perimeter intrusion alarms and video recording functions.

 

2. Control and Operation

The PV power generation system shall control grid-connected equipment at the site in accordance with power grid dispatch instructions and perform the corresponding operating procedures. As part of maintaining a solar power system, these procedures include the regulation of PV equipment AGC, AVC, primary frequency regulation, and other related systems.

 

Remote start-up and shutdown operations shall be performed for equipment such as PV inverters.

 

Power generation parameters shall be adjusted according to the requirements of the PV power station.

 

3. Inspection of PV Equipment

Targeted inspection routes, inspection items, and inspection intervals shall be developed based on the scale of the PV power generation system, equipment configuration, and other relevant characteristics. In principle, inspections should be conducted by at least two people working as a team.

 

Inspections shall be strengthened, and the inspection frequency appropriately increased, when the operating mode changes, weather conditions change, or special operating modes are adopted.

 

Inspection records shall be properly maintained. Any equipment defects identified shall be reported and addressed promptly.

 

 

4. Defect Management of a Solar Power System

Defect management is an essential part of maintaining a solar power system and shall be carried out through a closed-loop process consisting of defect identification, recording, classification, rectification, and acceptance.

 

Defect Identification

Defects are mainly identified through regular inspections, special inspections, equipment operation procedures, instrument and signal feedback, scheduled maintenance, supervision and inspection conducted at various levels, and acceptance inspections for newly constructed, renovated, or expanded projects.

 

Defect Recording

Once a defect is identified, it shall be registered promptly, clearly, in detail, and accurately. After the defect has been eliminated, the rectification details shall be recorded in a timely manner. The entire process from defect identification to elimination shall be tracked to ensure closed-loop management of equipment defects.

 

Defect Classification

Defects may be classified into three levels according to their severity: critical defects, major defects, and general defects.

 

• Critical defects: Defects that threaten personnel or equipment safety, may cause an accident at any time, seriously affect the continued operation of the equipment, and therefore require immediate or urgent rectification.
• Major defects: Defects that have a certain impact on equipment service life or output, or that may develop into critical defects, but which still allow the equipment to continue operating for a short period or to be monitored and analyzed.
• General defects: Defects that have a relatively minor impact on the safe operation of equipment, generally will not develop into either of the two types of defects described above, and allow the equipment to continue operating at its nameplate rated value. Such defects may be included in the monthly, quarterly, or annual maintenance plan for rectification.

 

General defects shall be assessed by the person in charge of the plant or station, or by the designated technical officer. Defects that are difficult to classify shall be submitted to the production and technical department of the relevant organization for review. The classification of critical and major defects shall be reviewed by the production and technical department of the relevant organization and submitted to the responsible leader for approval. After a critical defect is identified, it shall be reported to the company's Production and Operations Department and Safety Supervision Department for record-filing within 24 hours.

Defect Rectification of Solar Power Systems

 

• Rectification of critical defects: To maintain a solar power system safely and reliably, decisions shall be made based on the system's operating conditions, as well as relevant regulations and procedures, regarding whether equipment affected by critical defects should be immediately removed from service. Monitoring of defective equipment shall be strengthened, emergency measures shall be formulated promptly, and all necessary preparations shall be made for emergency repairs.
• Rectification of major defects: A defect-elimination plan shall be formulated promptly and implemented in an organized manner. In general, the closed-loop rectification process should be completed within one month.
• Rectification of general defects: General defects may be addressed in conjunction with monthly or quarterly maintenance plans. Minor defects that can be handled by the operation and maintenance personnel shall be rectified immediately and recorded in the defect log. For equipment defects that cannot be rectified immediately due to the lack of suitable conditions, or that have not been eliminated or have only been partially eliminated, temporary measures shall be taken to ensure equipment safety, and inspections shall be strengthened. Once the necessary conditions are available, rectification shall be arranged promptly. In general, such defects should be eliminated within three months.

 

Defect Acceptance

After defect rectification is completed, general defects shall be inspected and accepted by the plant or station. Major and critical defects shall be inspected and accepted by the enterprise. The company's Production and Operations Department shall conduct random checks on the acceptance of major defects by each organization.

 

Equipment Inspection and Maintenance of a Solar Power System

1. Inspection and Maintenance of PV Modules

 

• Obstructions that cast shadows on PV modules shall be removed promptly.
• The surface of PV modules shall be cleaned according to the operating conditions of the power station. Corrosive solvents shall not be used for cleaning, and hard objects shall not be used to wipe the modules. In special conditions, such as winter, water-saving cleaning methods shall be adopted.
• In the event of sandstorms, heavy snow, hail, or similar conditions, the surface of the PV modules shall be cleaned promptly.
• PV modules that can no longer operate normally shall be replaced promptly.
• Fasteners that are visibly loose shall be addressed promptly.

 

No.	Inspection Content	Inspection Method	Inspection Frequency	Abnormal Conditions	Corrective Measures and Precautions
1	Visual Inspection	Visual Inspection	Once a month	Broken glass, scorched backsheet, or obvious color changes	Replace the PV module
				Bubbles forming conductive paths between the edge of a PV module or between any circuits
				Junction box deformed, distorted, cracked, or burned; terminals not properly connected
2	PV module surface dust and shading	Visual inspection and instrument measurement	Once a month (adjust the interval as appropriate based on actual conditions)	Dust or dirt on the PV module surface, causing a significant reduction in power generation efficiency	Clean the PV module surface by manual wiping, water washing, mechanical cleaning, or automatic cleaning with a cleaning robot, as appropriate; remove obstructions by cutting tree branches, clearing weeds, installing fences, and taking other measures
3	Operating temperature	Instrument measurement	Once every six months	Under conditions where solar irradiance is not less than 500 W/m² and wind speed is not greater than 2 m/s, the temperature difference on the external surface of the same PV module exceeds 20°C; hot spot on PV module	Replace or continue monitoring
4	Insulation test	Instrument measurement	Once every six months (sampling inspection)	With a test voltage of 1,000 V, insulation resistance to ground with the positive and negative terminals short-circuited, the positive terminal to ground, or the negative terminal to ground is below the specified standard value	Identify insulation problem points and take insulation measures

2. Inspection and Maintenance of Mounting Structures and Foundations

 

• The mounting structures and foundations are essential components of a solar power system and require regular inspection and maintenance to ensure safe and stable operation.
• Bolts and connection points between the mounting structures and foundations shall be inspected regularly to prevent loosening.
• Any cracking or peeling of the anti-corrosion coating on the surfaces of the mounting structures and foundations shall be addressed promptly.
• The drive mechanisms of tracking structures, including rotating shafts and motors, shall be inspected regularly. Any faults identified shall be addressed promptly.
• Mounting structures and equipment foundations shall also be inspected regularly, and any damaged or defective foundations shall be repaired promptly.

 

Mounting Structure and Foundation Inspection and Maintenance Items

 

No.	Inspection Content	Inspection Method	Inspection Frequency	Abnormal Conditions	Corrective Measures and Precautions
1	Foundation	Visual inspection and tool-based inspection	Once every six months (add temporary inspections when abnormalities occur)	Foundation settlement, displacement, or inclination exceeds design requirements	Correct according to design requirements
				Damage to foundation surface	Repair
2	Mounting structure condition	Visual inspection and tool-based inspection	Once every six months (add temporary inspections when abnormalities occur)	Overall deformation or misalignment of PV array	Correct according to design requirements
				Damage or looseness of load-bearing members, connection components, and connection bolts; looseness of module clamps	Tighten or replace
3	Anti-corrosion condition	Visual inspection and tool-based inspection	Once every six months	Peeling of rust-proof coating on metal materials or corrosion	Remove rust and apply anti-corrosion treatment; replace severely corroded components
4	Mounting structure grounding	Instrument measurement	Once every six months	Abnormal grounding position of mounting structure; grounding resistance greater than 4 Ω	Inspect grounding circuit, correct grounding position, or replace part of circuit

 

3. Inspection and Maintenance of PV Inverters

 

PV inverters are critical components of a solar power system, and regular inspection and maintenance are essential to ensure their safe and reliable operation. During inverter operation and maintenance, attention shall be paid to the integrity of all structural connections. Problems such as dust accumulation, rust, and corrosion should be prevented as far as possible, and warning signs shall remain clear and visible. Routine maintenance includes the following:

 

• If the inverter nameplate or identification label becomes detached, or if the exterior is damaged, it shall be replaced or repaired promptly.
• The equipment shall be cleaned regularly to prevent dust accumulation.
• Abnormal faults shall be addressed promptly, and vulnerable components shall be replaced regularly.
• Regular inspections shall be conducted to ensure the integrity of all structural connections.
• Any rust or corrosion found on the equipment shall be addressed promptly.

 

No.	Inspection Content	Inspection Method	Inspection Frequency	Abnormal Conditions	Corrective Measures and Precautions
1	System operating status	Visual inspection and operational test	Once every six months	Inverter exterior damage or deformation	Perform corrective maintenance
				Excessive vibration and abnormal noise during inverter operation
				Abnormal heating of inverter enclosure	Monitor system temperature, check inverter parameters, and investigate abnormalities
2	System cleanliness	Visual Inspection	Once every six months	Dust on inverter surface; air inlets/outlets blocked or clogged with dust	Clean accumulated dust promptly
3	Electrical connections	Visual inspection and operational test	Once every six months	Loose cable connection	De-energize and repair; replace promptly in serious cases
				Cuts on the surface of cables that are in contact with metal surfaces
4	Warning labels	Visual Inspection	Once every six months	Warning labels on inverter damaged, curled, or detached	Replace labels
5	Fan	Visual inspection and operational test	Once every six months	Excessive vibration and abnormal noise during cooling fan operation	De-energize for repair and replace promptly
				Cracks in fan blades
6	Circuit breaker	Operational test	Once every six months	AC/DC circuit breaker abnormal; switch failure	Replace promptly
7	Input/output terminals	Visual Inspection	Once every six months	Loose or broken terminals	Tighten or replace terminals
8	Inverter output power quality	Operational test	Once every six months	Exceeds standard limits	Optimize software and rectify
9	Inverter error inspection	Review recorded information	Once every six months	Inverter function error	Rectify according to the reported error
10	Inverter internal surge protection	Visual Inspection	Before the rainy season or when a problem is identified; address promptly	Device failure	Replace

 

4. Inspection and Maintenance of Combiner Boxes

 

• Combiner boxes are important components of a solar power system, and regular inspection and maintenance are essential to ensure their safe and reliable operation.
• If the outgoing-cable nameplate or identification label of a combiner box becomes detached, or if its exterior is damaged, the issue shall be addressed promptly.
• Aged components inside the combiner box shall be maintained or replaced as necessary.
• The sealing condition of the combiner box shall be inspected regularly, and any defective sealing components shall be replaced promptly.

 

No.	Inspection Content	Inspection Method	Inspection Frequency	Abnormal Conditions	Corrective Measures and Precautions
1	Visual Inspection	Visual inspection and operational test	Once every six months	Enclosure deformation, corrosion, water leakage, or dust accumulation	Repaint, clean dust, and inspect or replace sealing components
				Damaged safety warning label	Reattach safety warning label
				Weatherproof lock cannot be opened or closed properly	Replace weatherproof lock
2	Inspection of internal terminals	Visual inspection and instrument measurement	Once every six months	Loose or corroded	Reinforce or replace
3	Internal temperature detection	Instrument measurement	Once every six months and after component replacement	Abnormal component temperature	Reinforce connections or replace components
4	DC fuse	Visual inspection and instrument measurement	Address promptly	Damaged	Replace
5	Insulation test	Instrument measurement	Once every six months (conduct simultaneously with PV module insulation test)	With a test voltage of 1,000 V, insulation resistance to ground of the positive and negative terminals of the DC output busbar when short-circuited, the positive terminal to ground, or the negative terminal to ground is less than 1 MΩ	Identify insulation problem points and take insulation measures
6	Surge protection device	Visual Inspection	Before the rainy season or when a problem is identified; address promptly	Device failure	Replace
7	DC circuit breaker	Operational test	Once every six months	Device malfunction or failure	Replace

 

5. Inspection and Maintenance of the Data Acquisition and Monitoring System

 

• The data acquisition and monitoring system plays an important role in maintaining a solar power system by providing real-time operational data and supporting system monitoring. Regular inspection and maintenance should include the following:
• Check the data and power-connection cables of all equipment in the data acquisition and monitoring system, and clean off accumulated dust.
• Clean dirt and debris from sensors such as anemometers, solar irradiance meters, and air temperature and humidity meters.
• Update antivirus software and clean and optimize the monitoring server.

 

No.	Inspection Content	Inspection Method	Inspection Frequency	Abnormal Conditions	Corrective Measures and Precautions
1	Data acquisition equipment	Visual inspection and instrument measurement	Once every six months	Monitoring host indicator lights abnormal, or monitoring host malfunction prevents data upload	(1) Check whether the host itself is operating normally; if not, repair or replace it. (2) Check whether the sensors are operating normally; if not, repair or replace them.
2	Network transmission equipment	Visual inspection and instrument measurement	Once every six months	Transmission interrupted or slowed; all displayed data interrupted or data upload slowed due to network problems	(1) Check transmission lines and interfaces; repair if problems are found. (2) Check whether transmission equipment is configured correctly and whether settings have been changed; reconfigure if abnormal. (3) Check whether the transmission equipment itself is operating normally; repair or replace if not. (4) Check whether devices on the network are infected with viruses; remove viruses if found.
3	Monitoring server	Visual inspection and software test	Once a month	Monitoring terminal running slowly, or abnormal CPU and memory utilization	Use antivirus software to remove viruses; clean disk and memory space and processes; if unresolved, reinstall the operating system and service software
4	Monitoring terminal host	Visual inspection and software test	Once every six months	Monitoring terminal host running slowly, or abnormal CPU and memory utilization	Use antivirus software to remove viruses; clean disk and memory space and processes; if unresolved, reinstall the operating system and terminal software
5	Anemometer	Visual inspection and instrument measurement	Once every six months	Abnormal wind-speed data displayed on monitoring page	Compare with a handheld device; disassemble for repair or replace if abnormal
				Abnormal wind-speed sensor; does not rotate or rotates only slightly in strong winds
6	Air temperature and humidity meter	Visual inspection and instrument measurement	Once every six months	Abnormal temperature or humidity data displayed on monitoring page	Compare with a handheld device; disassemble for repair or replace if abnormal
7	Precipitation	Visual inspection and instrument measurement	Once every six months	Abnormal precipitation data displayed on monitoring page	Disassemble for repair or replace
8	Solar irradiance meter	Visual inspection and instrument measurement	Once a month	Abnormal irradiance data displayed on monitoring page	(1) Confirm that the sensor tilt angle and azimuth match the design; calibrate if misaligned. (2) If abnormality persists after calibration, disassemble for repair or replace.
9	Inverter input/output energy	Data comparison	Once every six months	Inverter energy reading differs abnormally from meter data	Repair or replace inverter
10	Monitored energy data	Data comparison or instrument measurement	Once every six months	Compare with manual meter-reading data from the revenue meter or instrument measurement data; displayed values are abnormal	Calibrate or replace monitoring equipment

 

Conclusion

Regular inspection and maintenance are essential to maintain a solar power system safely, reliably, and efficiently. By monitoring equipment, identifying and resolving defects promptly, and following scheduled maintenance procedures, operators can extend system service life, improve power generation performance, and maximize long-term return on investment.