Silicon solar panel capacity refers to the power generated by flat panel solar panel WP. The power value of solar power generation depends on the power H (WH) consumed by the load for 24h. The capacity P (AH) consumed by the load for 24h is determined by the rated power supply of the load and the power consumed by the load for 24h.
Taking into account the average sunshine hours per day and the impact of cloudy and rainy days, the working current IP (A) of the solar energy battery array is calculated.
The nominal voltage of the battery is selected from the rated power supply of the load. The number of batteries in series and the floating charge voltage VF (V) of the battery are determined by the nominal voltage of the battery.
Considering the impact of the temperature rise voltage VT (v) of the solar cell caused by the temperature rise and the voltage drop VD (V) of the reverse charge diode P-N junction, the working voltage VP (V) of the solar cell array can be calculated.
According to the working power supply IP (A) and working voltage VP (V) of the solar array, the power generation WPW of the flat panel solar panel can be determined, so as to design the capacity of the solar panel. According to the designed capacity WP and the working voltage VP of the solar array, the number of series and parallel groups of the silicon panel can be determined.
The specific design steps of the solar array are as follows:
1. Calculate the load 24h consumption capacity P.
P=H/VH – power consumed by load for 24 hours (WH)
V – Load rated power supply
2. Select the daily sunshine hours T (H).
3. Calculate the working current of the solar array.
IP=P (1+Q)/TQ — according to the surplus coefficient in rainy period, Q=0.21 ～ 1.00
4. Determine the floating charge voltage VF of the battery.
The single floating charge voltage of nickel cadmium (GN) and lead acid (CS) batteries is 1.4 ～ 1.6V and 2.2V respectively.
5. Solar cell temperature compensation voltage
VT=2.1/430(T-25)VF
6. Calculate the working voltage VP of the solar array.
VP=VF+VD+VT
VD=0.5 ～ 0.7
Approximately equal to VF
7. Solar array output power WP, flat solar panel.
WP=IP × VP
8. Determine the number of series blocks and parallel groups of standard specifications according to the table of VP and WP in the silicon cell panel combination series.
In addition, conversion efficiency of inverter and other power losses shall be considered for AC systems or grid connected system.
Example:
Taking 100W output power for 5 hours a day as an example, the following calculation method is introduced:
1. First, calculate the watt hours consumed per day (including inverter loss): if the conversion efficiency of the inverter is 90%, when the output power is 100W, the actual required output power should be 100W/90%=111W; If it is used for 5 hours per day, the power consumption is 111W * 5 hours=555Wh.
2. Calculation of solar panel:
The output power of the solar panel shall be 555Wh/6h/70%=130W based on the daily effective sunshine time of 6 hours, taking into account the charging efficiency and the loss in the charging process. Among them, 70% is the actual power used by the solar panel during the charging process.
