Dust Monitoring System for Solar Panel

1.Dust Monitoring System for Solar Panel Product Overview

Dust Monitoring System for Solar Panel can accurately detect the impact of dust on photovoltaic panels, timely warning and treatment.Contamination on the glass of solar panels is one of the main problems that quickly affects photovoltaic power plants, reducing power generation efficiency and cost-effectiveness. Dust pollution can significantly reduce the power generation of photovoltaic power plants, estimated to be at least 5% per year. The optical closed-loop measurement of blue light pollutants (OMBP) technology can be easily installed in new or existing photovoltaic arrays and integrated into the power plant management system. The device is installed on the frame of the photovoltaic panel. By continuously measuring the transmission loss caused by contaminants on the glass, the reduction in sunlight reaching the solar panel is calculated.

By measuring the contaminant ratio (SR), it is converted into a loss of power generation in real time. This allows operators to know when the contaminants have reached a critical point and it is necessary to start a cleaning procedure. The product does not require maintenance, just clean it in the same way as the surrounding components.

Because large PV plants have different pollution rates throughout the park, multi-point measurement is required in the IEC 61724-1 standard. Compared with traditional systems, the purchase cost, installation and maintenance costs are much lower, which makes it more economical, so clean-up can be planned when and where it is needed.

2. Impact of dust on photovoltaic power generation

Everyone knows that dust covers the components, forming a shielding phenomenon, which directly leads to a decrease in the power output of the components. In addition, the long-term adhesion of dust has a certain corrosive effect on the components. At the same time, the constant presence of dust will cause hot spots on the components, further reducing the output power of the components and even affecting the life of the components. In addition, the hot spot effect is irreversible for the components. Once it appears and there is no way to make up for it, the only option is to replace the components. Otherwise, it will affect the power generation and may also bring safety hazards to the power station.

Several domestic and foreign research institutions have conducted research on the effect of dust on photovoltaic system power attenuation, and the data obtained are shown in Figure 1.

From the above figure, we can see that the output power of my country's photovoltaic system is affected by dust by an average of about 20%.

The impact of dust on photovoltaic power generation can be mainly attributed to the following three aspects:

1. Temperature influence

Currently, photovoltaic power stations mostly use silicon-based solar cell modules, which are very sensitive to temperature. As dust accumulates on the surface of the modules, the heat transfer resistance of the modules increases, becoming an insulating layer on the modules and affecting their heat dissipation.

Studies have shown that when the temperature of a solar cell rises by 1°C, the output power drops by about 0.5%. Moreover, when the solar cell is exposed to sunlight for a long time, the temperature of the covered part rises much faster than that of the uncovered part, causing the temperature to be too high and dark spots of burnt out appear.

Under normal illumination conditions, the covered part of the solar panel will change from a power generation unit to a power consumption unit, and the shaded photovoltaic cell will become a load resistor that does not generate electricity, consuming the power generated by the connected battery, that is, generating heat, which is the hot spot effect. This process will accelerate the aging of the solar panel, reduce the output, and in severe cases, cause the components to burn out.

2. Occlusion Impact

Dust adheres to the surface of the solar panel, which will block, absorb and reflect light, the most important of which is the blocking of light. The reflection, absorption and blocking of light by dust particles affect the absorption of light by photovoltaic panels, thereby affecting the efficiency of photovoltaic power generation.

Studies have shown that dust deposited on the light-receiving surface of the solar panel assembly will first reduce the light transmittance of the panel surface; secondly, it will change the incident angle of some light, causing uneven propagation of light in the glass cover.

Studies have shown that under the same conditions, the output power of clean solar panel components is at least 5% higher than that of dusty components, and the higher the amount of dust, the greater the decline in component output performance.

3. Corrosion

The surface of photovoltaic panels is mostly made of glass. The main components of glass are silicon dioxide and limestone. When moist acidic or alkaline dust adheres to the surface of the glass cover, the components of the glass cover can react with the acid or alkali.

As the glass is exposed to acidic or alkaline environments for a longer period of time, the surface of the glass will slowly be corroded, resulting in pits and bumps on the surface, causing diffuse reflection of light on the cover surface, destroying the uniformity of light transmission in the glass. The rougher the cover of the photovoltaic module, the less energy the refracted light has, and the less energy actually reaches the surface of the photovoltaic cell, resulting in a decrease in the power generation of the photovoltaic cell. In addition, a rough, sticky surface with adhesive residues is more likely to accumulate dust than a smoother surface. Moreover, dust itself will also attract dust. Once initial dust exists, more dust will accumulate, accelerating the attenuation of photovoltaic cell power generation.

3. Features of Dust Monitoring System for Solar Panel

1. Real-time data monitoring: It can collect and analyze four types of data: pollution ratio, clean ratio, dust thickness, and backplane temperature. The pollution ratio and clean ratio use dual probes

The mean data calculation mode ensures that the data is accurate and reliable.

2. Technological collector: The dust environment data collector adopts a new generation of 32-bit MCU processor, with high-precision 4G and Bluetooth digital chips integrated on board, which can send the collected data to the data monitoring platform via wired or wireless means.

3. Innovative blue light technology: The new generation of blue light pollutant optical closed-loop measurement (OMBP) technology is used to effectively ensure high-precision dust data detection and effectively prevent sunlight from interfering with the optical closed-loop data collection. It can be used for a long time in all-weather conditions, which is better than the requirement in the "IEC 61724-1 standard" that effective monitoring can only be performed for three hours from 11:00 to 13:00 every day.

4. Smart power station cleaning: Built-in new generation of IoT control module, with four control modes: normally open and normally closed, cycle control, time control, manual control. According to the set pollution threshold and control mode, it can link cleaning robots or IoT control equipment to automatically clean the dust on the solar panels to ensure the high efficiency of photovoltaic power stations.

5. Accuracy self-calibration: The device is integrated with a one-button accuracy self-calibration button. Depending on the application environment and different usage time, the acquisition accuracy of the device will decrease. The self-calibration button can automatically recalibrate the blue light monitoring circuit to ensure accurate and reliable data observation.

6. Green power management: This data logger can adopt two power supply modes: AC220V and DC12V. A new generation of green power management module is integrated inside to realize intelligent switching between AC and DC power supply.

4. Technical Specifications of Dust Monitoring System for Solar Panel