Many households have installed solar photovoltaic power stations. While enjoying the various benefits brought by photovoltaics, it is also important to remember to maintain and clean them.

Proper maintenance and upkeep can not only ensure the power generation of the power station, but also guarantee sufficient service life.

Next, let’s talk about the daily maintenance of photovoltaic power plants!

Cleaning of pollutants

The lifespan of a typical photovoltaic module is around 25 years. Regularly cleaning the module panel of bird droppings, leaves, and other obstructions can ensure maximum exposure to sunlight.

If you usually prefer cleanliness and have high requirements for power generation efficiency, you can also clean the components yourself, but you need to pay attention to the following points.

1. Generally, component cleaning work is carried out in the morning or late afternoon. When personnel are cleaning, it is prohibited to stand less than 1 meter away from the edge of the roof for work.

2. Before cleaning the components, it is necessary to check whether there are any records of abnormal power output in the monitoring records, analyze whether it may cause leakage, and check whether the connecting wires and related components of the components are damaged or adhered.

Before cleaning, it is also necessary to use a test pen to test the aluminum frame, bracket, and tempered glass surface of the components. To eliminate potential electrical hazards and ensure personal safety.

3. Personnel performing component cleaning should wear appropriate work clothes and hats to avoid scratching and injury. Hooks and straps should be prohibited on clothing or tools. Components such as wire ends that are prone to entanglement.

4. It is strictly prohibited to clean photovoltaic modules under weather conditions such as strong winds, heavy rain, thunderstorms, or heavy snow. Winter cleaning should avoid rinsing, and do not rinse the panel with cold water when it is very hot.

5. It is strictly prohibited to use hard and sharp tools, corrosive solvents, and alkaline organic solvents to wipe photovoltaic modules. It is also forbidden to spray cleaning water onto component junction boxes, cable trays, combiner boxes, and other equipment.

Maintenance of components and brackets

1. The surface of photovoltaic modules should be kept clean, and dry or damp soft and clean fabrics should be used to wipe the photovoltaic modules. It is strictly prohibited to use corrosive solvents or hard objects to wipe the photovoltaic modules.

Photovoltaic modules should be cleaned under irradiance below 200W/O, and it is not advisable to use liquids with large temperature differences from the modules for cleaning.

2. The live warning signs on photovoltaic modules must not be lost.

3. Photovoltaic modules should be regularly inspected, and if the following problems are found, the photovoltaic modules should be adjusted or replaced immediately.

——Photovoltaic modules have glass shattering, back plate burning, and obvious color changes;
——There are bubbles in photovoltaic modules that form communication channels with the edges of the modules or any circuits;
——The junction box of the photovoltaic module is deformed, twisted, cracked or burned, and the wiring terminals cannot make good contact.

4. For photovoltaic modules with metal frames, the frame and bracket should be well combined, and the contact resistance between the two should not exceed 4 Ω. The frame must be firmly grounded.

5. Use a DC clamp type ammeter to measure the input current of each photovoltaic module string connected to the same DC combiner box under conditions where the solar radiation intensity is basically the same, and the deviation should not exceed 5%.

Maintenance of combiner box

1. The DC combiner box shall not have deformation, rust, water leakage, or dust accumulation. The safety warning signs on the outer surface of the box shall be intact and undamaged, and the waterproof lock on the box body shall be flexible to open and close.

2. The wiring terminals inside the DC combiner box should not be loose or corroded.

3. The specifications of the high-voltage DC fuse inside the DC combiner box should comply with the design specifications.

4. The insulation resistance of the positive pole to ground and negative pole to ground of the DC output bus should be greater than 2 megohms.

5. The DC circuit breaker equipped at the DC output bus end should have flexible and reliable breaking function.

6. The lightning arrester inside the DC combiner box should be effective.

Maintenance of inverters

1. The structure and electrical connections of the inverter should be kept intact, and there should be no rusting, dust accumulation, or other phenomena.

The heat dissipation environment should be good, and there should be no significant vibration or abnormal noise during the operation of the inverter.

2. The warning signs on the inverter should be intact and undamaged.

3. The cooling fans of modules, reactors, and transformers in the inverter should start and stop automatically according to temperature, and there should be no significant vibration or abnormal noise during the operation of the cooling fans. If there are any abnormal situations, the power should be cut off for inspection.

4. Regularly disconnect the AC output side (grid side) circuit breaker once, and the inverter should immediately stop feeding power to the grid.

5. If the temperature of the DC bus capacitor in the inverter is too high or exceeds its service life, it should be replaced in a timely manner.

Maintenance of cables

1. The parts of the cable entering and exiting the equipment should be well sealed, and there should be no holes with a diameter greater than 10mm. Otherwise, fireproof mud walls should be used for sealing.

2. The cable protection steel pipe mouth should not have perforations, cracks, or significant unevenness. The inner wall should be smooth, and the metal cable conduit should not have severe rust, burrs, hard objects, or garbage. If there are burrs, they should be filed and wrapped with a cable jacket and tied tightly.

3. The stakes along the buried cable line should be intact and undamaged, and there should be no excavation on the ground near the path.

Ensure that there are no heavy objects, building materials, or temporary facilities piled up on the ground along the path, and that there is no discharge of corrosive substances. Ensure that the cable protection facilities on the exposed ground are intact.

4. Ensure that the cover plate of the cable trench or cable well is intact, there should be no accumulated water or debris in the trench, the brackets in the trench should be firm, free of rust or looseness, and the outer skin and armor of the armored cable should not be severely corroded.

5. For multiple cables laid in parallel, the current distribution and temperature of the cable sheath should be checked to prevent cable burning out of connection points due to poor contact.

Extreme weather maintenance

1. If it rains and trips, it may be due to loose connectors. If such a situation occurs, it must be dealt with after the rain has cleared. Insulation tape can be used to wrap the connectors, and then observe whether the trip occurs. If the trip continues, it should be reported to the maintenance center or local power station.

2. On thunderstorm days, the air switch below the electricity meter should be turned off to prevent damage to electrical equipment. After the thunderstorm, close the switch.

It is worth mentioning that everyone should not underestimate the cleaning and maintenance work of household photovoltaic power plants. After cleaning, the power generation of the power plant can be increased by 5% -30%, and the cleaning frequency should be ten times a year or once a month.