How to Choose a Solar Street Light: 7 Checks Before You Sign a Contract
Every year we see the same failures in the field: lights that die after one cloudy week, poles that lean after the first storm, batteries that fade within 18 months. Almost all of them trace back to decisions made before the contract was signed. Here is the checklist we give every government buyer and EPC contractor we work with.
1. Real wattage, not "rated" wattage
The market is full of "300W" lights that draw 60W. Ask the supplier for the LED drive current and total luminaire lumens, not the wattage printed on the housing. A genuine 100W all-in-one at 170 lm/W produces about 17,000 lumens — anything far above that in a small housing is physics fiction.
2. Battery grade and chemistry
Insist on Grade-A LiFePO4 cells from a named manufacturer, with cycle life data (2,000+ cycles at 80% depth of discharge). B-grade and recycled cells are the single most common cause of early failure — and they cost only slightly less.
3. Do the autonomy math yourself
Autonomy = battery Wh ÷ daily consumption. Example: a 12.8V 30Ah battery stores 384Wh. A 60W light running 12 hours at an average 30% power (motion-dimmed profile) consumes ~216Wh — roughly 1.8 nights of backup. For monsoon or Sahel seasons, specify 3–5 nights and size the panel and battery accordingly.
4. Panel: mono, and big enough
Monocrystalline only. Panel wattage should be at least 1.2× the daily consumption ÷ local peak sun hours. If a supplier's panel looks small relative to the lamp power, the system will chronically undercharge — the leading cause of "works in summer, dies in winter."
5. Wind load and pole spec
For 8m+ installations, request the pole's wind-resistance calculation for your site. Coastal typhoon zones need reinforced brackets; desert zones need foundation adjustments for sandy soil. A quality supplier provides foundation drawings free of charge.
6. Certifications that actually matter
- CE + RoHS — baseline for Europe, Africa, Middle East
- IP66 test report — not just "IP66" printed on the housing
- LM-79 / LM-80 — photometric and lumen maintenance data
- CCC — verifies the factory is audited (for China-manufactured goods)
- SONCAP / PVOC / SASO — destination-specific clearance certs
7. Verify the supplier is a factory
Ask for: business license scope, a live video factory tour, and photos of pole production (rolling, welding, galvanizing) — not just lamp assembly. Trading companies disappear after the first after-sales issue; factories have a reputation to protect.
Bottom line
A solar street light is a 5–10 year infrastructure decision, not a commodity purchase. The cheapest quote is usually the most expensive one after replacement and maintenance costs. If you want a second opinion on a quotation or BOQ, send it to us — we'll review it free, even if you don't buy from us.