The capacity of silicon solar panels refers to the power generation of flat panel solar panels. The power value of solar power generation depends on the power H (WH) that can be 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.
Then, considering the influence of average sunshine hours per day and cloudy and rainy days, the working current IP (a) of the solar cell array is calculated.
The nominal voltage of the battery is selected from the rated power supply of the load, and the number of batteries in series and the floating charge voltage VF (V) of the battery is determined from the nominal voltage of the battery.
Then, considering the influence 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 cell array, the power generation power 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 cell array, the number of series blocks and parallel groups of the silicon cell flat panel can be determined.
The specific design steps of solar cell array are as follows:
1. Calculate the 24h load consumption capacity P.
P = H / VH – power consumed by the load for 24 hours (wh, w) ˙ Time)
V – load rated power supply
2. Select 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 season, q = 0.21 ~ 1.00
4. Determine the floating charge voltage VF of the battery.
The single floating charge voltages of cadmium nickel (GN) and lead-acid (CS) batteries are 1.4 ~ 1.6V and 2.2V respectively.
5. Solar cell temperature compensation voltage
VT。 VT=2.1/430(T-25)VF
6. Calculate the working voltage VP of the solar cell array.
VP=VF+VD+VT
Where VD = 0.5 ~ 0.7
Approximately equal to VF
7. Solar cell array output power WP, flat panel 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 silicon battery flat-panel combination series.
In addition, inverter conversion efficiency and other power losses shall be considered for AC systems or grid-connected systems.
Example：
Taking 100W output power for 5 hours a day as an example, the calculation method is introduced below:
1. First, calculate the watt-hours consumed every day (including the loss of inverter): if the conversion efficiency of the inverter is 90%, when the output power is 100W, the actual required output power shall 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:
Based on the daily effective sunshine time of 6 hours, and considering the charging efficiency and loss during charging, the output power of the solar panel shall be 555wh / 6h / 70% = 130W. Among them, 70% is the actual use power of solar panels during charging.
