Compared with ordinary solar lighting, the design of solar street lamps has the same basic principle, but there are more links to consider. The following is an example of photosynthetic solar LED high-power street lamp, which is analyzed from several aspects.
Solar cell module selection
Design requirements: in sanmenxia area, the load input voltage is 24V, the power consumption is 34.5w, the working hours are 8.5h per day, and the continuous rainy days are guaranteed for 7 days.
(1) the average annual radiation in sanmenxia area in recent 20 years is 107.7Kcal/cm2, and the peak sunshine hours in changsha area are about 3.424h after simple calculation.
The daily power consumption for the load = = 12.2AH
The total charging current of the photosynthetic solar module required by changsha is = 1.05 12.2 (20+7) 20 (3.424 0.85) = 5.9a
The minimum total power of the photosynthetic solar modules = 17.2 5.9 = 102W
With a peak output of 110Wp and a single 55Wp standard battery pack, the street lamp system should be able to operate normally for most of the year.
The calculation of battery design capacity is simpler than that of solar module peak wattage.
According to the above calculation, the daily power consumption of the load is 12.2AH. In the case of full battery, can work for 7 consecutive rainy days, plus the first night of work, battery capacity: 12.2 x (7+1) = 97.6 (AH), choose 2 12V100AH battery can meet the requirements.