The highway billboard solar power generation system can not install too many solar panels on the top of billboards because of the constraints of construction conditions and users' consideration of costs. In order to meet the needs of floodlight lighting at night, when designing the system, it is necessary to make full use of the limited components to enhance the power generation effect.
1. Factors influencing the solar power generation include whether the system configuration is reasonable, whether the component lighting direction is correct, whether the tilt angle of the component is reasonable, and the shadow of the solar energy system. The shadow of the solar system includes shadows, shadows, shadows, mutual overlap of components, dust, bird droppings, etc., surrounding the billboards. Solar shading has a great impact on the system's power generation efficiency, and produces a hot spot effect that shortens component life and damages components. Therefore, when installing a solar panel, it is necessary to fully consider the influence of actual operating conditions such as latitude, spectrum, temperature, and shading of the billboard on the output of the solar cell.
The so-called solar hot spot effect means that the solar cell module is exposed to sunlight, and some of the components are blocked and cannot be operated, and will be used as the energy consumed by the other solar modules that consume the light, so that the covered parts will be heated much larger. In the uncovered part, burnt dark spots appear due to excessive temperatures. Hot spot effects may cause damage to the entire battery pack.
In practical applications, in order to achieve the desired photoelectric conversion efficiency, the series or parallel connection between components must have similar characteristics. Components with different specifications, different performances, and different manufacturers must not be mixed.
2. The choice of azimuth and tilt angle of solar modules is one of the most important factors in the design of solar power systems. The so-called azimuth generally refers to the north-south direction of the east-west direction. The azimuth angle is 0° to the south, south to east and north to negative angles, and the southward to northward angle to the north. If the sun is in the lower east direction, the azimuth is -90°, and in the west it is 90°. The azimuth angle determines the direction of the sun's incident and determines the component's lighting conditions. In clear summer, the maximum time of solar radiation energy is at noon, so when the orientation of the square is slightly westward, the maximum generating power can be obtained in the afternoon. In different seasons, the orientation of the solar cell array is slightly eastward or westward, with some generating the largest amount of electricity.
The tilt angle is the angle between the ground plane (horizontal plane) and the solar module. When the tilt angle is 0°, the solar battery module is horizontally installed, and when the tilt angle is 90°, the solar battery module is vertically set. The optimal angle of inclination is the angle of inclination that allows solar cells to generate as much power as possible, and the difference in power generation between winter and summer is as small as possible.
3. In the absence of strong winds and rain-flooding weather, billboards on highways are often covered with thick dust on the surface of solar panels. Birds in the nearby woods often stop and excrete on the surface of components. The power loss has a very large impact and the power generation efficiency is reduced by at least 6%. However, in practical applications, people cannot do regular cleaning and cleaning components. This problem has always been a problem.
4. The outdoor billboard solar array is composed of multiple components connected in series and in parallel. The series connection will cause current loss due to the current difference of the components, and the parallel connection will cause voltage loss due to the voltage difference of the components. The combined loss can reach more than 8%, and the standard of China Engineering Construction Standardization Association is less than 10%. In order to reduce the combined power loss, it is recommended to strictly select components with the same current performance before purchasing and installation.
5. The maximum output power of solar modules increases with the increase of solar radiation intensity and decreases with the decrease of solar radiation intensity.
In addition, the solar modules are also related to the ambient temperature. In the normal operating temperature range of the modules, the lower the ambient temperature, the greater the output power of the modules; the higher the ambient temperature, the smaller the output power of the modules. The influence of temperature on silicon solar cells is mainly reflected in changes in parameters such as open circuit voltage, short-circuit current, and peak power of the solar cell as a function of temperature.
In the hot summer, the back surface temperature of the solar cell module can reach 70°C, and the operating junction temperature of the solar cell can reach 100°C at this time (the rated parameters are all calibrated at 25°C). Silicon solar cells work under high temperature conditions, and the open circuit voltage drops sharply with the increase of temperature. At the same time, the charging work point is seriously offset, and the system is easily deficient due to insufficient charging. The output power of silicon solar cells also increases with temperature. The sharp drop resulted in the solar modules failing to maximize their performance.
Therefore, according to the use of different environments, increase the number of solar panels, in order to compensate for the voltage loss and power loss caused by the increase in temperature, to ensure the normal value of the system power generation.
6. Outdoor billboards for solar power generation are independent solar energy off-grid systems and must use energy storage devices. Commonly used lead-acid batteries, the operating temperature of the battery capacity has a greater impact. At low temperatures, the capacity of the battery increases as the temperature increases. However, an excessively high temperature can also adversely affect the battery, resulting in a decrease in battery capacity and a shortened life.
Lead-acid batteries are not easy to work at low temperatures for a long time. For example, when the discharge capacity at -30°C is only 30% of the rated capacity, the battery's maximum performance cannot be achieved. The higher the temperature, the higher the self-discharge rate of the battery. Therefore, the battery should be stored in a high temperature environment.
The float charge life of lead-acid batteries varies with temperature. Basically, the float life is reduced by about half for every 10°C increase. The high temperature will accelerate the dehydration of the battery, thermal runaway, positive electrode grid corrosion and deformation. Low temperature will cause negative electrode passivation failure, temperature fluctuations will accelerate the internal short circuit of lead-acid batteries, etc., which will affect the battery life. Therefore, try to make the battery work under the ambient temperature of 5 °C ~ 35 °C, in practical applications, the battery should be placed in a ventilated, but also a good insulation performance of the box. In order to save time and reduce costs, some installers directly lift the battery up and leave it bare in the aisle, which will seriously affect the performance and service life of the battery.
7. The solar controller is an important component to ensure the smooth operation of the entire solar power system. Quality will directly affect the charging effect. Some manufacturers use extremely simple controllers to save costs. In the short period of time after operation, there are phenomena such as failure to charge normally and excessive deep discharge. The fatal result is that the battery is in a state of depletion for a long time. The entire system is paralyzed and the loss is huge. .
8. Solar power is a DC system. The distance between the components and the controller and the battery should not be too far away. The cable connecting the controller to the floodlight of each billboard must be of good quality and have a sufficient diameter. Never cut corners. The cross-sectional area and length of the cable determine the size of the resistor. The current determines the amount of voltage or power loss. The larger the current, the greater the voltage loss, the greater the power loss, and the longer the time passed, the more the power loss.
At the same time, special attention must be paid to whether the connectors and terminals are firm.
1. Factors influencing the solar power generation include whether the system configuration is reasonable, whether the component lighting direction is correct, whether the tilt angle of the component is reasonable, and the shadow of the solar energy system. The shadow of the solar system includes shadows, shadows, shadows, mutual overlap of components, dust, bird droppings, etc., surrounding the billboards. Solar shading has a great impact on the system's power generation efficiency, and produces a hot spot effect that shortens component life and damages components. Therefore, when installing a solar panel, it is necessary to fully consider the influence of actual operating conditions such as latitude, spectrum, temperature, and shading of the billboard on the output of the solar cell.
The so-called solar hot spot effect means that the solar cell module is exposed to sunlight, and some of the components are blocked and cannot be operated, and will be used as the energy consumed by the other solar modules that consume the light, so that the covered parts will be heated much larger. In the uncovered part, burnt dark spots appear due to excessive temperatures. Hot spot effects may cause damage to the entire battery pack.
In practical applications, in order to achieve the desired photoelectric conversion efficiency, the series or parallel connection between components must have similar characteristics. Components with different specifications, different performances, and different manufacturers must not be mixed.
2. The choice of azimuth and tilt angle of solar modules is one of the most important factors in the design of solar power systems. The so-called azimuth generally refers to the north-south direction of the east-west direction. The azimuth angle is 0° to the south, south to east and north to negative angles, and the southward to northward angle to the north. If the sun is in the lower east direction, the azimuth is -90°, and in the west it is 90°. The azimuth angle determines the direction of the sun's incident and determines the component's lighting conditions. In clear summer, the maximum time of solar radiation energy is at noon, so when the orientation of the square is slightly westward, the maximum generating power can be obtained in the afternoon. In different seasons, the orientation of the solar cell array is slightly eastward or westward, with some generating the largest amount of electricity.
The tilt angle is the angle between the ground plane (horizontal plane) and the solar module. When the tilt angle is 0°, the solar battery module is horizontally installed, and when the tilt angle is 90°, the solar battery module is vertically set. The optimal angle of inclination is the angle of inclination that allows solar cells to generate as much power as possible, and the difference in power generation between winter and summer is as small as possible.
3. In the absence of strong winds and rain-flooding weather, billboards on highways are often covered with thick dust on the surface of solar panels. Birds in the nearby woods often stop and excrete on the surface of components. The power loss has a very large impact and the power generation efficiency is reduced by at least 6%. However, in practical applications, people cannot do regular cleaning and cleaning components. This problem has always been a problem.
4. The outdoor billboard solar array is composed of multiple components connected in series and in parallel. The series connection will cause current loss due to the current difference of the components, and the parallel connection will cause voltage loss due to the voltage difference of the components. The combined loss can reach more than 8%, and the standard of China Engineering Construction Standardization Association is less than 10%. In order to reduce the combined power loss, it is recommended to strictly select components with the same current performance before purchasing and installation.
5. The maximum output power of solar modules increases with the increase of solar radiation intensity and decreases with the decrease of solar radiation intensity.
In addition, the solar modules are also related to the ambient temperature. In the normal operating temperature range of the modules, the lower the ambient temperature, the greater the output power of the modules; the higher the ambient temperature, the smaller the output power of the modules. The influence of temperature on silicon solar cells is mainly reflected in changes in parameters such as open circuit voltage, short-circuit current, and peak power of the solar cell as a function of temperature.
In the hot summer, the back surface temperature of the solar cell module can reach 70°C, and the operating junction temperature of the solar cell can reach 100°C at this time (the rated parameters are all calibrated at 25°C). Silicon solar cells work under high temperature conditions, and the open circuit voltage drops sharply with the increase of temperature. At the same time, the charging work point is seriously offset, and the system is easily deficient due to insufficient charging. The output power of silicon solar cells also increases with temperature. The sharp drop resulted in the solar modules failing to maximize their performance.
Therefore, according to the use of different environments, increase the number of solar panels, in order to compensate for the voltage loss and power loss caused by the increase in temperature, to ensure the normal value of the system power generation.
6. Outdoor billboards for solar power generation are independent solar energy off-grid systems and must use energy storage devices. Commonly used lead-acid batteries, the operating temperature of the battery capacity has a greater impact. At low temperatures, the capacity of the battery increases as the temperature increases. However, an excessively high temperature can also adversely affect the battery, resulting in a decrease in battery capacity and a shortened life.
Lead-acid batteries are not easy to work at low temperatures for a long time. For example, when the discharge capacity at -30°C is only 30% of the rated capacity, the battery's maximum performance cannot be achieved. The higher the temperature, the higher the self-discharge rate of the battery. Therefore, the battery should be stored in a high temperature environment.
The float charge life of lead-acid batteries varies with temperature. Basically, the float life is reduced by about half for every 10°C increase. The high temperature will accelerate the dehydration of the battery, thermal runaway, positive electrode grid corrosion and deformation. Low temperature will cause negative electrode passivation failure, temperature fluctuations will accelerate the internal short circuit of lead-acid batteries, etc., which will affect the battery life. Therefore, try to make the battery work under the ambient temperature of 5 °C ~ 35 °C, in practical applications, the battery should be placed in a ventilated, but also a good insulation performance of the box. In order to save time and reduce costs, some installers directly lift the battery up and leave it bare in the aisle, which will seriously affect the performance and service life of the battery.
7. The solar controller is an important component to ensure the smooth operation of the entire solar power system. Quality will directly affect the charging effect. Some manufacturers use extremely simple controllers to save costs. In the short period of time after operation, there are phenomena such as failure to charge normally and excessive deep discharge. The fatal result is that the battery is in a state of depletion for a long time. The entire system is paralyzed and the loss is huge. .
8. Solar power is a DC system. The distance between the components and the controller and the battery should not be too far away. The cable connecting the controller to the floodlight of each billboard must be of good quality and have a sufficient diameter. Never cut corners. The cross-sectional area and length of the cable determine the size of the resistor. The current determines the amount of voltage or power loss. The larger the current, the greater the voltage loss, the greater the power loss, and the longer the time passed, the more the power loss.
At the same time, special attention must be paid to whether the connectors and terminals are firm.
