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How to calculate the configuration of solar street lamp?
- Jul 16, 2018 -

The calculation of current
For example: 12V battery system; Two 30W lamps, 60 watts in total.
The current = 60W / 12V= 5a

Capacity calculation
For example, the lighting time of street lamps is 9.5 hours per night, and the actual full load lighting is 7 hours (h).
Example 1:1 LED lamp
(if 100% power is turned on at 7:30 PM, it will be reduced to 50% power at 11:00 PM, 100% power after 4:00 am, and closed at 5:00 am)
Example 2:2-way non-led lamp (low pressure sodium lamp, non-polar lamp, energy-saving lamp, etc.)
(for example, two roads open at 7:30 PM, one at 11:00 PM, two at 4:00 am and five at 5:00 am)
It needs to meet the lighting requirements for 5 consecutive days of rainy and cloudy days. (5 days plus lighting for the night before cloudy or rainy, 6 days)
Battery = 5A * 7h * (5+1) days
5A times 42h is equal to 210 AH
In addition, in order to prevent overcharge and overdischarge of the battery, the battery is generally charged to about 90%; Discharge residual about 5%-20%. So 210AH is only about 70-85% of the true standard in the application. In addition, the actual loss should be measured according to different loads. The actual working current is affected by constant current source, ballast, line loss, etc., which may increase by 15%-25% on the basis of 5A.

The cumulative lighting time of street lamps at night shall be 7 hours (h);
Breathing: the average daily effective light exposure time of the panels is 4.5 hours (h);
At least 20 per cent of the reserve for panels will be relaxed.
The best way to solve this problem is to find out the best way to solve it
WP present 17.4 V = 9.33
WP = 162 (W)
The daily light time is the sunshine coefficient of the area near the middle and lower reaches of the Yangtze river at 4.5h.
In addition, in the solar street lamp components, the wire loss, controller loss, and ballast or constant current source power consumption are different, the actual application may be around 15-25%. So 162W is just the theoretical value, and it's going to increase depending on the actual situation.

Author:Bunny Sun