01 Objective environment: "external conditions" that cannot be ignored
A: Poor lighting conditions
Photovoltaic power generation is actually the principle of photovoltaic effect of semiconductor P-N junction, using solar cells to directly convert solar energy into electrical energy. Therefore, in cloudy, rainy or hazy days with less sunshine, the power generation of photovoltaic power stations will be reduced accordingly.
B: Too high temperature
The working efficiency of photovoltaic modules will decrease with the increase of temperature. In summer, the power generation of photovoltaic power stations may not be as high as in sunny weather in spring or autumn. This is because the continuous high temperature in summer has a great impact on the modules. When the temperature rises, the output power of the modules will decrease.
C: Influence of obstructions
Module obstruction will also affect the power generation. For example, a string of modules under the same MPPT circuit is obstructed by 2 blocks. According to the MPPT algorithm, the maximum power point is found by adjusting the voltage. In the above situation, there will be two power peak points, the MPPT tracking point will be lower than normal, and the power generation efficiency will be reduced.
02 System design: details determine success or failure
A: Tilt and orientation
The installation tilt and orientation of photovoltaic modules directly affect their effect of receiving solar radiation. If the tilt and orientation are not set properly, the local light resources cannot be fully utilized. For example, in the northern hemisphere, if the photovoltaic panels are not facing south, but east or west, then at certain times of the day, the light intensity received by the photovoltaic panels will be weakened, thereby reducing the power generation.
B: Improper capacity configuration
The module capacity, inverter capacity and transformer capacity of the photovoltaic power station need to be reasonably matched. If the configuration is improper, it will lead to low system efficiency.
03 Equipment conditions: core hardware for power station operation
A: Component aging and attenuation
Photovoltaic modules will gradually age during use, resulting in a decrease in conversion efficiency and a decrease in power generation.
B: Component damage
The modules may be damaged during transportation, installation, and cleaning, such as hidden cracks, hot spots, etc., which will affect the power generation efficiency.
C: Inverter failure
The inverter is a key device that converts DC power into AC power. If the inverter fails, the power generation will decrease or even the system will shut down.
D: Line loss
Excessive cable length, thin wire diameter, poor connection, etc. will increase line loss, which may trigger overvoltage protection and affect power generation efficiency.
04 Operation and maintenance management: the "soft power" of efficient operation of power stations
A: Inadequate cleaning and maintenance
The accumulation of dust and dirt on the surface of photovoltaic modules will affect the light transmittance and reduce power generation efficiency. Regular cleaning and maintenance are important measures to ensure power generation.
In areas with abundant rainfall, photovoltaic modules do not need to be cleaned frequently, but in areas with little precipitation and high dust, photovoltaic modules need to be cleaned regularly with water.
When cleaning, you need to check whether there is dust accumulation on the bottom edge of the photovoltaic module. At the same time, be careful not to step on the module during the cleaning process to avoid hidden cracks in the module, affecting power generation, or even electrical accidents.
B: Imperfect monitoring system
A perfect monitoring system can monitor the operation status of the power station in real time, detect equipment failures and abnormal power generation in time, and contact the corresponding manufacturer in time to avoid the expansion of losses.
C: Insufficient professional ability of operation and maintenance personnel
The operation and maintenance of photovoltaic power stations requires professional personnel. If the operation and maintenance personnel lack experience, it may lead to problems such as improper equipment maintenance and untimely fault handling, which will affect the power generation.
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Optimization strategy
A: Optimal site selection
Select areas with rich light resources and suitable climatic conditions to build power stations, and do a good job of preliminary terrain and environmental surveys to avoid the influence of obstructions and reasonably design the orientation of components.
B: Equipment selection
Select photovoltaic components and inverters with reliable quality and excellent performance. For the component strings under the same MPPT circuit, it is recommended to select photovoltaic panels of the same brand and conduct regular equipment inspection and maintenance. At the same time, select efficient and stable photovoltaic inverter equipment to increase the power generation of the power station through high conversion efficiency.
C: Design and Installation
When designing and installing the system, be sure to pay attention to the orientation of the photovoltaic modules. Generally speaking, the system has the highest power generation efficiency when facing south and at the best tilt angle. Other factors also need to be considered, such as snow accumulation, terrain conditions, and land area. The orientation and tilt angle of the modules should be selected based on the above factors to ensure the best system efficiency.
D: Operation and Maintenance Management
Establish a complete operation and maintenance management system, regularly clean the modules, check the operating status of the equipment, and use the monitoring system to monitor the power generation in real time, so as to find and solve problems in time.