With the increasing shortage of traditional energy, the application of solar energy will be more and more extensive, especially in the field of solar power generation in just a few years has developed into a mature sunrise industry.
1: currently, restrict the application of solar power is one of the most important part of the price, with a light dual solar street lights, for example, two road load sharing is 60 watt, (effective illumination in the middle and lower reaches of the Yangtze river area 4.5 h/day, 7 hours each night discharge, calculate the panels to 20% increase in reserve) the panels will need to about 160 w, 30 yuan per watt calculation, the cost of the panels will be 4800 yuan, plus 180 ah battery costs are at around 1800, the whole street to invest cost and much higher than the mains street lamp, caused a major bottleneck in the field of solar street light applications.
2: the service life of the battery should also consider in the whole street lamp system application, usually the battery warranty of three years or five years, but the general battery in one year or even half a year later will be in charge of discontent, some actual charge rate may fall to about 50%, it will affect the normal continuous rainy period of night lighting, so choose a good battery is especially important.
3: some engineering companies often choose LED lamps as the illumination of solar street lamps, but the quality layer of LED lamps is not uniform, serious light decline of LED half a year may reduce 50% of the illumination. So must choose the light decline slower LED light, or choose the infinite light, low pressure sodium lamp.
4. The selection of the controller is often ignored by the engineers. The quality level of the controller is uneven. The quality of the controller directly affects the component life of the solar street lamp system and the procurement cost of the whole system. First, the controller with low power consumption should be selected. The controller works 24 hours without interruption. 2. Choose a controller with high charging efficiency. The controller with MCT charging mode can automatically track the maximum current of the panel. The controller with power regulation has been widely promoted. It can automatically turn off the lighting of one or two routes at night when there are few pedestrians, so as to save electricity and adjust the power of LED lights. In addition to select the saving function, but also should pay attention to the protection function of controller for battery and other components, as has a trickle charge mode controller can very good protection batteries, increase the service life of battery, the other set controller under-voltage protection value, as far as possible the under-voltage protection value in 11.1 V or higher, to prevent the battery discharge.
5: far from the city should also pay attention to the anti-theft work, a lot of engineering business because of construction negligence, no effective anti-theft, resulting in batteries, panels and other components stolen, not only affect the normal lighting, but also caused unnecessary property losses. In project case by pilfer in the majority is accumulator, accumulator is buried in the ground with cement pouring build it is measure of a kind of effective guard against theft, in lamp post
It is better to weld and reinforce the battery case.
6: the controller is waterproof, the controller is generally installed in the lamp shade, battery box, generally will not water, but in the actual engineering case, the connection line of the controller terminal is often because the rain water flows into the controller along the connection line to cause a short circuit. So in the construction should pay attention to the internal connection line bent into "U" type and solid, the external connection line can also be fixed as "U" type, so that the rain can not be poured into the controller short circuit, in addition, can also be inside and outside the interface coating waterproof glue.
7: in many practical applications, the solar street lamps in many parts of the solar street light can't meet the needs of the normal lighting, especially in the rainy day is more outstanding, in addition to use the poor quality of the related components, is another major reason why blindly reduce component costs, no configuration is designed according to the demand, reduce the use standard panels and batteries, so in a rainy day street lamp lighting can not be provided. The following formula is provided for calculating the configuration of solar panels and batteries:
First, calculate the current:
For example: 12V battery system; Two 30W lamps, 60 watts in total.
Current = 60W 12V = 5a
Two: calculate the battery capacity demand:
For example, the cumulative lighting time of street lamps per night shall be 7 hours at full load (h);
(such as opening at 8:00 PM, closing at 11:30 PM, opening at 4:30 am, closing at 5:30 am)
The lighting needs should be satisfied for 5 consecutive days of overcast and rainy days. (5 days plus lighting on the night before overcast and rainy, 6 days)
Battery = 5A 7h (5+1) day = 5A 42h =210 AH
In addition, in order to prevent over charge and over discharge of the battery, the battery is generally charged to about 90%; Discharge remaining 20% or so.
So 210AH is only about 70% of the real standard in the application.
Iii. Calculate the peak demand for panels (WP) :
The cumulative lighting time of street lamps per night shall be 7 hours (h);
: the average daily effective light exposure time of the solar panel is 4.5 hours (h);
At least relax the panel demand for 20% of the reservation.
WP 17.4v = (5A 7h 120%) 4.5h
WP present 17.4 V = 9.33
WP = 162 (W)
: the daily sunshine duration for 4.5 hours is the sunshine coefficient of the area near the middle and lower reaches of the Yangtze river.
In addition, in the solar street lamp components, the loss of the line loss, loss of the controller, and the power consumption of the ballast or constant current source are different, the actual application may be about 5-25%. So 162W is also just a theoretical value, but it needs to be increased according to the actual situation.