- Start with the site and lighting task
- Match the four main components
- Compare integrated and split arrangements
- Calculate lighting and energy separately
- Ask for numbers that can be checked
- Compare battery conditions and service
- Choose the controller with the panel and battery
- Include civil work and replacement costs
- Review a representative system
A solar street light is a lamp, panel, battery, and controller working together. Compare the energy balance and the lighting layout before comparing the wattage printed on the housing.
Start with the site and lighting task
Record road or path dimensions, pole positions, required light levels, nightly operation, shading, weather, and access for maintenance. Confirm the road-lighting and structural criteria for the location.
Match the four main components
The lamp sets demand, the panel supplies energy, the battery stores usable capacity, and the controller manages charging and operation. Ask for the ratings and model details of each part, including losses and temperature limits.
Compare integrated and split arrangements
An integrated unit can simplify mounting but limits panel position and available space. A split system can allow independent panel orientation and easier access to parts, with more separate mounts and wiring to manage.
Calculate lighting and energy separately
Use photometry to check the lamp layout. Calculate daily energy from watts at each operating level multiplied by hours. Size the panel using the solar resource in the design month, with losses, and size the battery for the required usable backup. The sizing tool is a starting estimate.
Ask for numbers that can be checked
Request complete-luminaire lumens and watts, optic, CCT, color rendering, panel rating, battery Wh and usable depth of discharge, controller settings, and protection ratings. Distinguish peak settings from the all-night operating schedule.
| Component | Details to request |
|---|---|
| LED luminaire | Measured watts and lumens, optic, CCT, and operating schedule |
| Solar panel | Rated output, dimensions, mounting, and seasonal energy estimate |
| Battery | Nominal Wh, usable capacity, temperature limits, and cycle-test conditions |
| Controller | Charge profile, power levels, sensor settings, and low-battery behavior |
| Pole and foundation | Site-specific structural design and installation details |
Compare battery conditions and service
Cycle life depends on depth of discharge, temperature, charge rate, and end-of-life criterion. Read those conditions with the cycle count. Confirm replacement availability, warranty, transport, and access to the battery.
Choose the controller with the panel and battery
An MPPT controller can track a panel’s operating point, but performance depends on the system configuration and conditions. Check input limits, battery profile, temperature protections, and the agreed night schedule.
Include civil work and replacement costs
Compare poles, foundations, installation, cleaning, batteries, access labour, and disposal over the same period. For a grid comparison, use equivalent lighting and local trenching and electricity costs.
Review a representative system
Check documents for the exact configuration, then trial it under relevant conditions. Confirm the recorded operating schedule, low-battery behavior, spare parts, warranty responsibilities, and how performance will be accepted.
Frequently Asked Questions
Does a higher wattage mean a better solar light?
No. Check measured output, distribution, nightly energy use, panel input, and usable battery capacity together.
How many cloudy nights will it cover?
Calculate usable battery energy divided by nightly demand, with the required temperature and ageing allowances. Ask for the assumptions.
Can a summer trial prove winter operation?
No. Review the seasonal solar resource and design-month energy balance.