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how many solar panel would be for 60w solar street light?

The peak sunshine hours of the installation site:5 hours

The load is 336WH, the solar panel should be 336WH*2/(5*0.8)=168W

Calculation process is as follows,

Determine the configuration, that is, how many watts of solar panels to charge full the batteries. 

In fact, it's power consumption of led lights and power generation of solar panel. 

Power consumption is usually measured by KWH,

which is broken down as follows: kWH = 1000 * WH. So 1WH is one thousandth of a kilowatt-hour.

Power consumption = LED solar street light power * full power working time

Take a 60W lamp working for 12 hours, 3 hours 70% brightness, 4 hours 50% brightness, 5 hours 30% brightness, the power consumption is:


Normally, the number of days supported by the lithium battery in rainy and cloudy days is 2-3 days, that is, when there is no sun in winter and autumn, the electricity in the battery can last for 2-3 days. But in actual use, once the battery is fully charged, it will last more than 2-3 days. On the one hand, even in rainy weather, solar panels can still charge some electricity. On the other hand, the controller has automatic power reduction, which can automatically reduce the brightness of the solar street light, according to the voltage dropped by the battery to save power. Through this series of measures to increase revenue and reduce expenditure, 3-5 days can be used.

Then we calculate according to 3 days, 

the storage capacity of the battery = the daily power consumption * the number of support in rainy and cloudy days:


and then divide by the voltage of the lithium battery to get the capacity, for example, we use 11.1V lithium battery, the capacity is 1008/12.8≈78.75AH

Next we will calculate the power of the solar panel.

The electricity generated by solar panels should be used to make up for the electricity that was used last night, and at the same time, the electricity to be used tonight should be fully charged, that is, 

Solar panel power generation = daily power consumption * 2

The power generation capacity of solar panels is calculated as follows:

Solar panel power generation = solar panel power * installation site sunshine peak hours * power generation efficiency

Solar panel power=daily power consumption*2/(peak hours of sunshine at installation location*generation efficiency)

The peak sunshine hours of the installation site can also be found on the Internet, we will take 4 (most places are around 4 hours, unless other places with particularly good sunshine can reach 5 hour).

The power generation efficiency of solar systems is generally 70-75%, 

so we take 75%.

Solar panel power: 336WH*2/(5*0.8)=168W

60w solar lights