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Solar Lighting Engineering Tool

Solar Street Light Sizing Calculator

Enter your road parameters and get instant wattage, battery, and solar panel recommendations — matched to real products with factory pricing.

Required Wattage Solar Panel Size Battery Capacity Matched Products
Free Tool

Size Your Solar Street Light System

Adjust the parameters below — results update in real time. No sign-up required.

Project Parameters

Enter your road and location details.

Residential streets need 10 lux average illuminance.

8 m
3 m30 m
8 m
4 m15 m
30 m
15 m50 m
4.5 h
3 h6 h
3 days
1 day7 days
10 h
6 h14 h

Calculation Results

Required Wattage
Required Lumens
Solar Panel Power
Battery Capacity
Coverage Area
Lux Requirement
Daily Energy Consumption
Maintenance Factor / Utilization Factor0.80 / 0.60
LED Efficacy180 lm/W

Parameter Explanation

  • Maintenance Factor (MF = 0.8): Accounts for lumen depreciation from dirt, aging, and LED degradation over time.
  • Utilization Factor (UF = 0.6): The fraction of total lamp lumens that actually reach the road surface.
  • LED Efficacy (180 lm/W): Average luminous efficacy of modern LED chips used in solar street lights.
  • Charging Efficiency (0.75): Accounts for losses in solar panel charging — MPPT controller efficiency, temperature, and wiring losses.
  • Depth of Discharge (0.85): Maximum battery discharge allowed to preserve LiFePO4 battery cycle life.
  • Controller Efficiency (0.8): Efficiency of the charge/discharge controller during battery operation.
Matched Products

Recommended Solar Street Lights

Products are matched based on your wattage and battery requirements. Prices are factory batch prices in RMB.

Enter your parameters to get recommendations

26 Models Available
5 Series | 10W-150W Range
Certified Quality
CE / ROHS / IEC60598 / IEC62722
LiFePO4 Battery
2500+ Cycles | 6-8 Year Lifespan
3-Year Warranty
MPPT Controller | 220 lm/W

Need Help Sizing Your Solar Street Light Project?

Get a free solar lighting design with pole layout, product selection, and factory pricing. B2B projects only.

FAQ

Solar Street Light Calculator FAQ

How do I calculate solar street light wattage?

To calculate solar street light wattage, first determine the required illuminance (lux) for your road type. Multiply the coverage area (pole spacing × road width) by the lux requirement, then apply the maintenance factor (0.8) and utilization factor (0.6) to get the required lumens. Finally, divide the lumens by the LED efficacy (approximately 180 lm/W) to get the required wattage. For example, a 240 m² area at 10 lux needs about 3,200 lumens or 18W of LED power.

How many solar panels do I need for a street light?

The solar panel power needed equals the daily energy consumption (wattage × operating hours) divided by the daily sunshine hours multiplied by a charging efficiency factor of 0.75. For example, a 60W light running 10 hours needs 600Wh per day. With 4.5 sunshine hours, you need approximately 178W of solar panel capacity (600 ÷ (4.5 × 0.75) = 178W). Our calculator handles this automatically.

What battery capacity do I need for rainy days?

Battery capacity (Wh) = daily energy consumption × rainy day backup ÷ (depth of discharge 0.85 × controller efficiency 0.8). For example, if your light consumes 600Wh per day and you want 3 days of backup, you need approximately 2,647Wh of battery capacity. LiFePO4 batteries are recommended for their long cycle life (2500+ cycles) and safety.

What is the difference between all-in-one and split solar street lights?

All-in-one solar street lights integrate the solar panel, battery, LED lamp, and controller into a single compact unit, making installation simple and cost-effective for residential streets, courtyards, and urban side streets (LKL and LKAS series). Split solar street lights separate the solar panel from the lamp head, allowing larger panel and battery configurations for main roads and highways where higher power output is needed (LKH, LFT, and LKA series). Split systems are also easier to maintain as individual components can be replaced independently.

How long do LiFePO4 batteries last in solar street lights?

LiFePO4 (lithium iron phosphate) batteries typically last 6 to 8 years in solar street light applications, with 2500+ charge cycles at 80% depth of discharge. They offer better thermal stability, higher safety, and longer lifespan compared to lead-acid or standard lithium-ion batteries. With a proper MPPT controller and 3-year warranty, LiFePO4 is the preferred choice for modern solar street lighting systems.