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In the promotion of green and sustainable development, the application of solar streetlights has become increasingly widespread. However, some users report encountering a common issue: a lack of understanding regarding the actual power of solar streetlights. To address this concern, we will discuss how to calculate the actual power of solar streetlights.
The actual power of solar streetlights is constantly changing.
Before explaining how to calculate the actual power of solar streetlights, it is important to clarify that the actual power is not static. Regardless of the method used, we can only determine an approximate actual power, which essentially represents the average power of solar streetlights during high brightness periods. Therefore, this value is quite referential.
Why is the actual power of solar streetlights constantly changing?
1. Before leaving the factory, solar streetlights are generally set to output power in 3-6 segments.
For example, in an overnight working scenario, the most common settings are as follows:
High brightness period (2-4 hours): 1 hour at 100% brightness + 2 hours at 60%-70% brightness.
Moderate brightness period (1-2 hours): 2 hours at 40% brightness.
Low brightness period (6-7 hours): 6 hours at 10% brightness.
Moderate brightness period (1-2 hours): 2 hours at 30%-40% brightness.
Calculating this way, the total power working time of the streetlight is approximately 4.5 hours. Of course, the total working time varies depending on customer requirements and configurations set by different manufacturers.
2. Automatic power reduction function of the controller.
The controller automatically adjusts the output power based on the battery voltage during each discharge, within the set parameters (not exceeding the maximum value).
Calculation Method 1: Clamp Meter Measurement Method.
If you have the programming remote control that matches the solar streetlight controller, you can directly read the parameters to know the actual power of the solar streetlight. However, end users generally do not possess a programmer, but a clamp meter is available for purchase. The reason for using a clamp meter is that it is more convenient to measure current than using a multimeter. It is essential to ensure that the clamp meter measures direct current and to pay attention to the current range. The testing steps are as follows:
Fully charge the battery.
Disconnect the charging cable and enter discharge mode.
Test the wire end connecting the controller and the light source.
Measure the voltage and current.
Calculate the actual power of the solar streetlight.
The clamp meter measurement method is simple and direct, and it is the recommended method among the three ways to calculate the actual power of solar streetlights. If you are patient enough to measure every hour, you can also determine how the manufacturer has set the power of the solar streetlight.
Calculation Method 2: Solar Panel Power Reverse Calculation Method.
The reverse calculation of the actual power of solar streetlights based on solar panels is based on the principle that the daily power generation of the solar panel equals the daily power consumption of the light source.
Daily power generation of the solar panel = Solar panel power x Peak sunlight hours / 2.22.
Daily power consumption of the light source = Actual power of solar streetlight x Total power working time.
The calculation formula is: Actual power of the light source = Solar panel power x Peak sunlight hours / Total power working time of the light source / 2.22.
Calculation Method 3: Battery Capacity Reverse Calculation Method.
This method requires that the depth of discharge of the lithium battery is controlled at 50%, which means using the battery over 2 days, indicating 2 absolute rainy days. Some solar streetlights deplete the battery fully within a day, which is not recommended, as continuous deep cycling significantly impacts battery lifespan. There are also some that deplete the battery over 3 days. However, due to cost reasons, most are configured for a 2-day depletion, which can vary based on the number of days.
Thus, Battery Energy (WH) = Actual power of the solar streetlight x Total power working time x 2 / Depth of discharge (90% for lithium batteries).
Battery Capacity (AH) = WH / V.
Therefore: Actual power of the light source = Battery capacity x Battery voltage / 2.22 / Total power working time of the light source.
This concludes our discussion on how to calculate the actual power of solar streetlights. We hope this article has been helpful. If you have any questions, feel free to leave a message, and we will respond promptly.
