The power of solar street lights depends on the width of the road and the surrounding environment, the height depends on the width of the road, and the distance between rows depends on the power of the light source and the secondary light distribution of the lamps. With the increasing scarcity of traditional energy sources, the application of solar energy will become more and more widespread, especially in the field of solar power generation has developed industry in a short period of several years.
1: One of the most important aspects of the current constraints on the application of solar power is the price, to a two-way solar street lamp, for example, two-way such as 6 downstream areas effective light 4.5h / day, 7 hours per night discharge, increase the battery plate 20% set-aside calculation) its battery plate requires about 160W, according to the cost of the battery plate will be 4800 yuan, plus the cost of about 180AH battery pack is also in 1800 or so, the whole street light one-time investment costs caused by the main bottleneck in the field of solar street lights.
2: The service life of the battery should also be considered in the whole street light system applications, the general battery warranty of three years or five years, the general storage of electricity will appear after six months of charging dissatisfaction, some actual charging rate may drop to about 50%, which will certainly affect the continuous rainy days period of the night to choose a better battery is particularly important.
3: Some engineers often choose LED lights for solar street lighting, but the quality of LED lights varies, light decay serious LED half 50% of the light level. So the best choice for long light life, high luminous efficiency, light decay is a slow LVD induction lamp, or choose a low-pressure sodium lamp, etc.
4: The choice of controller is often a problem ignored by engineers, the quality of the controller varies, 12V/10A controller market price varies, although it is the smallest part of the value of the entire street lighting system, it is a very important link. Damage to the controller directly affects the life of the solar components and the purchase cost of the whole system,: you should choose a controller with low power consumption, the controller works 24 hours a day, such as its own power consumption part of the electrical energy, it is best to choose the power consumption in the 1 mA (MA) below the controller. Second: you should choose a controller with high charging efficiency, with MCT charging mode to track the maximum current of the panel, especially in winter or the period of insufficient light, MCT charging mode is about 20% more efficient than the other. Third: adjust the power of the controller, with power regulation of the controller, has been widely promoted, in the night time pedestrian scarce time can automatically close one way or two-way lighting can be adjusted for the power of LVD lights. In addition to choosing the above power-saving features, should also focus on the controller to the battery and other components of the protection function as the type of controller can well protect the battery and increase the life of the battery, in addition, to set the controller Undervoltage protection value when trying to put the Undervoltage protection value to prevent the battery over-discharge.
5: far from the city should also pay attention to theft prevention, many engineers because of construction negligence, no effective anti-theft, resulting in the theft of storage components, not only affect the normal lighting but also caused unnecessary property losses. At present, the majority of engineering cases are stolen for the storage battery, the battery buried building is an effective anti-theft measure, the best way to add the battery box on the light pole will be welded and reinforced.
6: controller waterproof, the controller is generally installed in the lampshade, battery box, generally will not enter the water, but in the actual engineering cases of the controller terminals for the rain along the connection line into the controller caused by a short circuit. So in the construction should pay attention to the internal connection line bent into a "U" and solid type, the external connection "U", so that the rain will not be able to rain into the controller caused by a short circuit, in addition to the internal and external line interface can be coated with waterproof rubber.
7: In many solar street lights in practice, many places of solar street lights can not meet the normal lighting needs, especially in rainy days more sudden amount of poorly related components, another major reason is to reduce the cost of components, not according to demand design configuration, minus the battery panels and batteries lead to the street lights in rainy days can not provide lighting.
The following provides solar panels and battery configuration calculation formula.
One: First calculate the current.
Such as a 12V battery system; 2 lights of 40W, a total of 80 watts.
Current = 80W ÷ 12V = 6.7 A
Two: Calculate the battery capacity requirements.
Such as the cumulative lighting time of the street light each night needs to be full load 7 hours (h); (such as 8:00 pm open, night 11:30 off 1 road, 4:30 am open 2 roads, 5:30 am off) need to meet the lighting needs of 5 days of continuous cloudy and rainy days. (5 days plus the night before the rainy day lighting, counting 6 days)
Battery = 6.7A × 7h × (5 + 1) days = 6.7A × 42h = 280 AH
In addition, in order to prevent the battery from being overcharged and over-discharged, the battery is generally charged to about 90%; the discharge balance is about 20%. So 280AH is only about 70% of the real standard in the application.
Third: Calculate the peak demand (WP) of the battery panel.
The cumulative lighting time needed for street lights is 7 hours (h) per night.
WP ÷ 17.4V = (6.7A × 7h × 120%) ÷ 4.5hWP ÷ 17.4V = 12.5
WP ＝ 217 (W): 4.5h daily light time is the daylight factor for the area near the middle and lower reaches of the Yangtze River. In addition, in the solar street light components, line loss, controller loss, and ballast or constant current source power consumption vary, the actual application may be in the range of 5%-25% so 162W is only a theoretical value, according to the actual situation needs to be increased.
