Why Solar PV Needs Weather Stations?

Why does solar PV need weather stations?

Solar photovoltaic (PV) power generation technology occupies an important position in the global energy transition, but its power generation efficiency and stability are significantly affected by meteorological conditions. Therefore, the establishment of a specialized solar PV weather station for real-time monitoring and data analysis is essential to ensure the efficient, safe and stable operation of PV power plants. The following are the core functions of a PV weather station and their importance:

 1. Solar irradiance monitoring

   - Function and role: Solar irradiance (including direct irradiance, scattered irradiance and total irradiance) is the core data of PV power generation. On a sunny day, the solar irradiance is high, and the power generation is correspondingly high; on a cloudy or cloudy day, the opposite is true. Through the irradiance data accumulated over a long period of time, combined with the cloudiness and solar altitude angle information in the weather forecast, an accurate power generation prediction model can be constructed, providing a strong guarantee for grid access and power dispatch.

   - Value: Accurate irradiance data help optimize power generation prediction, support grid load regulation and power dispatch, and improve the overall efficiency of the system.

 2. Temperature Monitoring

   - Function and Role: The power generation efficiency of PV modules varies with temperature, and the efficiency decreases at high temperatures. For example, in summer, the surface temperature of the module may reach 60-70°C, which is much higher than the standard test temperature of 25°C, resulting in a significant decrease in power generation efficiency. Through temperature monitoring, the power generation prediction can be corrected in time, guiding O&M personnel to take heat dissipation measures to improve power generation efficiency.

   - Value: Temperature data is not only used to adjust the power generation efficiency model, but also helps to design a more effective heat dissipation system and prolong the module life.

 3. Wind Speed Monitoring

   - Function and Role: Wind speed is crucial to the safety of PV power plants. Excessive wind speed can cause strong wind pressure on PV modules and racking, which may lead to equipment damage. The common design wind speed range is 20-28m/s. Exceeding this range may cause system damage or failure.

   - Value: Real-time wind speed data helps warn of strong winds and guide O&M personnel to take protective measures, such as lowering the height of the racking or suspending power generation, to minimize losses caused by wind damage. In addition, wind speed data can also be used to assess the cooling effect of wind on PV panels and optimize the layout of the power plant.

 4. Precipitation Monitoring

   - Function and role: Precipitation has a double impact on PV power stations. Heavy rain, hail and other inclement weather may directly damage PV modules, especially in strong winds and hail, the surface of the modules is prone to impact; while in arid areas, the lack of precipitation will lead to the accumulation of dust, which affects the light transmittance and power generation efficiency.

   - Value: By monitoring the amount and intensity of precipitation in real time, the weather station can do drainage and protection work in advance to avoid equipment being soaked or damaged. Meanwhile, the precipitation data helps to assess the degree of dust accumulation on the surface of the modules and rationalize the cleaning arrangement to maintain the efficient operation of the power generation system.

 5. Humidity Monitoring

   - Function and role: Humidity has a direct impact on the performance of PV modules. Excessive humidity may cause water droplets or mold to appear on the module surface, affecting the light transmission rate and thus reducing power generation efficiency. In dry areas with little rainfall, dust tends to accumulate, further affecting power generation efficiency.

   - Value: Humidity data, when used in conjunction with precipitation data, can help assess the extent of dust buildup on the module surface and determine when to perform cleaning work to ensure long-term stable operation of the PV system.

 6. Barometric Pressure Monitoring

   - Function and Use: Changes in barometric pressure are usually closely related to changes in weather. Low barometric pressure is often accompanied by bad weather, such as heavy rain, lightning, strong winds, etc., while high barometric pressure usually means clear weather. The monitoring of barometric pressure can help predict weather changes and further enhance the accuracy of power generation forecasts.

   - Value: Barometric pressure data provides inputs to weather models, which helps in long-term performance evaluation and system optimization, and supports more complex weather analysis.

 Functions and Value of Sensors Required for Solar PV Weather Stations

In order to comprehensively monitor meteorological parameters related to PV power generation, solar PV weather stations are equipped with a variety of high-precision sensors. The following is a detailed description of common sensors and their functions and values:

 1. Solar Radiation Sensor (e.g. NBL-W-HPRS)

   - Function and role: Based on the thermopile principle, it accurately measures the total amount of solar radiation, including direct and scattered radiation. Its high absorptivity coating ensures efficient capture of solar energy, and the temperature-compensated design reduces the impact of ambient temperature changes on the measurement results.

   - Value: Provides PV power plants with basic data for power generation prediction, helping to optimize plant layout and module angles to ensure maximum light energy conversion. The irradiance data accumulated over a long period of time helps to build accurate power generation prediction models to support grid scheduling and load management.

 2. Temperature and humidity sensor (e.g. NBL-W-LBTH)

   - Function and role: Monitoring the temperature and humidity of the environment has a direct impact on the efficiency of PV modules. High temperature reduces module efficiency, and humidity may affect the cleanliness of the module surface, leading to a decrease in light transmission rate.

   - Value: Temperature data is used to adjust the power generation efficiency model and guide the heat dissipation design, while humidity data assists in assessing potential dirt accumulation and optimizing the cleaning schedule to ensure that the module surface is clean and efficient power generation is maintained.

 3. Wind Speed and Direction Sensor (e.g. NBL-W-DS/NBL-W-SS)

   - Function and role: Monitoring wind speed and direction is critical to the structural safety of PV panels. Strong winds may cause damage to the power plant, especially when the wind speed exceeds the design wind speed (20-28m/s), which may trigger equipment damage or failure.

   - Value: Early warning of extreme weather to ensure O&M safety. Meanwhile, wind speed data can be used to assess the cooling effect and assist in optimizing the PV array layout to improve the overall efficiency of the system.

 4. Panel Temperature Sensor(e.g. NBL-W-PPT)

   - Function and role: mounted on the back of the PV module, it accurately measures the temperature of the module and reflects the actual working condition. Module temperature directly affects power generation efficiency, and efficiency loss at high temperatures needs to be compensated and calculated by temperature data.

   - Value: Used to correct power generation prediction, help operation and maintenance personnel find abnormal heating conditions in time, take corresponding heat dissipation measures or maintenance operations, prolong the life of the module, and enhance power generation efficiency.

 5. Atmospheric Pressure Sensor

   - Function and Role: Although not often mentioned in particular, changes in atmospheric pressure indirectly affect the climate conditions and have a supporting role in long-term power generation performance analysis.

   - Value: Combined with other meteorological parameters, it provides inputs for more complex meteorological models, contributes to long-term performance assessment and system optimization, and supports finer power generation forecasts and dispatch decisions.

 6. Precipitation Sensor

   - Function and role: Real-time monitoring of precipitation, including weather phenomena such as rain and hail. Heavy rain or hail may cause physical damage to PV modules, especially in strong winds and hailstorms, where the module surface is susceptible to impact.

   - Value: Helps to prevent damage to modules from flooding and impact, ensuring smooth drainage and avoiding soaking of modules. At the same time, precipitation data helps to assess the degree of dust accumulation on the module surface and rationally arrange cleaning work to maintain the efficient operation of the power generation system.

 Summary:

The solar PV weather station realizes comprehensive monitoring of the environment around the PV power plant by integrating a variety of high-precision sensors. The comprehensive analysis of these data not only ensures the safe and stable operation of the power station, but also improves the power generation efficiency and reduces the operation and maintenance costs, which is an indispensable technical support for realizing the efficient use of PV energy. Specifically, the data provided by the weather station plays an important role in the following aspects:

1. Real-time monitoring: the sensor can monitor the meteorological conditions in the area where the PV power station is located in real time, including temperature, humidity, wind speed, wind direction and so on. These data are crucial for the operation and maintenance of the power plant, helping the power plant to adjust its operation strategy in time to ensure safe and efficient operation.   

2. Intelligent Early Warning: Based on the monitoring data from the sensors, the weather station can provide early warning of unfavorable meteorological conditions that may affect the operation of the PV power plant, such as strong winds and heavy rain. This provides the O&M team with a valuable window of time to carry out safety checks and protective measures, effectively avoiding power plant failures and losses caused by meteorological factors.

3. Energy efficiency analysis: Through the meteorological data collected by the sensors, the weather station can conduct energy efficiency analysis to assess the power generation efficiency of the PV power plant. This provides a scientific basis for optimizing the layout of the power station and enhancing the power generation capacity, which helps the power station achieve higher economic benefits.

4. Reduce operation and maintenance costs: the sensor can warn of potential meteorological disasters and power generation efficiency decline in advance, so that the power station can take measures to prevent and respond in advance, thus reducing the operation and maintenance costs and failure rate.

In summary, the solar PV weather station provides important data support for the power generation prediction, O&M management and safety assurance of PV power stations by accurately monitoring meteorological factors (such as irradiance, temperature, wind speed, precipitation, humidity, etc.). These meteorological data not only enhance the efficiency of PV power generation, but also provide early warning of extreme weather and help prevent equipment damage, thus realizing the long-term stable operation of PV power plants. By deploying appropriate sensors, the weather station is able to provide comprehensive, real-time meteorological monitoring for PV power plants, providing a strong guarantee for power scheduling and system optimization.

Pyranometer Solar Radiation Sensors data sheet

NBL-W-SRS-Solar-radiation-sensor-instruction-manual-V4.0.pdf

NBL-W-HPRS-Solar-Radiation-Sensor-Instruction-Manual-V3.0.pdf