How Much Does Cost of Solar Street Lights?

ZGSM Solar

To control the cost of solar street lights, the panel and battery configuration must be determined first.

We should know that before choosing solar street lights, we should make some preparations, such as where are the solar street lights installed? What is the latitude and longitude? How wide is the road? How about the rainy weather? How long does it take to keep the light on? In this way, we can better determine some parameters of solar street lights, choose the configuration, and bring a good lighting experience.

cost of solar street lights

So in this process, how to determine the configuration parameters of solar street lights? Today we will mainly look at how to determine the configuration of solar panels and batteries.

cost of solar street lights

Configuration of solar cell parameters

We can give an example to illustrate that a 12V 60W street lamp requires a full load of 7 hours of cumulative lighting time per night and 3 consecutive rainy days. The local sunshine coefficient is 4 hours.

Battery capacity

a. Calculate the current

Current=60W÷12V=5A

b. Calculate the battery capacity

First of all, you must understand that it is rainy for 3 consecutive days, but do not use this value directly for subsequent calculations. You must also add the lighting from the previous night, which is 4 days.

Battery = current × lighting time per night × number of days = 5A × 7h × 4 days = 140AH

However, it should be noted that 140AH is not the final capacity, and the problem of battery overcharge and overdischarge needs to be taken into consideration. In application, 140AH should only be about 70% to 85% of its true standard, and the actual working current of solar street lights will also be affected by Due to the influence of constant current source, ballast, line loss, etc., the current will increase by about 15% to 25% based on 5A.

Therefore, taking this factor into account, the battery capacity must also be recalculated for this case.

Minimum battery capacity=140AH÷85%×115%=189AH

Maximum battery capacity=140AH÷70%×125%=250AH

Panel power

Before calculating the power of the panel, we should know that the solar panel is composed of cells. There are generally 36 cells connected in series. Regardless of the size of a single cell, the voltage is about 0.48~0.5V. The solar panel itself The voltage is approximately between 17.3V and 18V. In addition, when calculating, relax at least 20% of the reservation for battery panel requirements.

solar street lights Panel
solar street lights Panel

Panel power ÷ panel operating voltage = (current × lighting duration per night × 120%) ÷ sunshine coefficient, then

Minimum battery panel power = (5A × 7h × 120%) ÷ 4h × 17.3V = 182W
Maximum battery panel power = (5A × 7h × 120%) ÷ 4h × 18V = 189W

However, this is not the final panel power, because during the operation of solar street lights, line losses, controller losses, and power consumption of ballasts or constant current sources must also be considered. Practical applications There are about 5%~25% of them, so the minimum 182W and 189W are only theoretical values, and they will increase according to the actual situation.

Minimum actual power of the battery panel = 182W × 105% = 191W
The actual maximum power of the battery panel = 189W × 125% = 236W

Therefore, in the example given, the minimum battery capacity is 189AH, and the maximum does not need to exceed 250AH. The power of the battery panel must be at least 191W, and the maximum capacity is 236W.

In addition

When purchasing solar street lights, according to these calculation formulas, clarify the lighting needs and clarify various conditions, and then you can better determine the configuration parameters of the solar street lights, complete high-quality configuration at the minimum cost, and bring excellent outdoor lighting experience.

Author

ZGSM Solar

We are a professional solar street light manufacturer with a 20-year history.

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