What Most Suppliers Won’t Tell You About Solar Street Lights

You’ve probably heard solar street lights marketed as a “set-and-forget” solution for clean, reliable outdoor lighting.

But the truth is: many solar street lighting systems underperform or fail early—not because solar technology doesn’t work, but because of what suppliers don’t tell you.

This article uncovers the hidden realities behind solar street lighting so you can make an informed decision and avoid costly mistakes.

1: Battery Lifespan Is Often Overstated

It’s common to see battery life claims of 5–10 years in product brochures. But dig deeper.

Most failures happen within 2 years because cheap lead-acid batteries are used instead of lithium or LiFePO₄ options.

Why do solar street light batteries fail early?
Cheap batteries with low cycle life and poor temperature tolerance often degrade within 1–2 years, causing premature failure.

If you're sourcing lights for a commercial or municipal project, demand batteries with at least 2000+ cycles and a Battery Management System (BMS).

2: Brightness Levels May Be Inadequate

Suppliers love to promote high “lumen” numbers. But that doesn’t always translate to actual ground brightness.

Low-quality LEDs and poor optics can result in uneven lighting or weak lux levels, compromising safety.

Ask for:

• IES simulation reports
• Pole height + beam spread specs
• Actual lux levels at 2–3m height

I've seen projects where 10,000-lumen fixtures barely lit a sidewalk—because they used poor lenses and weak diodes.

3: Solar Panels Are Sometimes Undersized

If the solar panel can’t generate enough energy—even on cloudy days—your lights will shut down before dawn.

Many suppliers save cost by undersizing solar panels relative to the load.

Key questions to ask:

• What's the wattage of the panel?
• What's the daily power draw of the LED fixture?
• Is there a backup for low-sunlight days?

Use this simple formula:
40W LED × 12 hours = 480Wh/day → Panel should provide at least 600Wh daily, accounting for inefficiencies.

4: No Mention of Real Backup Days

Suppliers often forget to mention autonomy—how many days a light can run without sunlight.

Systems with less than 2-day autonomy are prone to blackouts during cloudy or rainy weather.

Ask for:

• Backup duration in Wh or Ah
• Depth of discharge level
• Battery reserve capacity

If you’re in a region with seasonal rain or snow, 3–5 days of backup is essential.

5: “All-in-One” Designs Sacrifice Durability

Compact “all-in-one” solar street lights look sleek and promise easy installation—but they hide real issues.

Integrated batteries and controllers in sealed housings often suffer from overheating and poor ventilation.

Consider split-type systems if durability and long-term servicing matter.

6: Poor Quality Control and Component Sourcing

Not all solar lights are built equal.

Some suppliers cut costs by using unbranded batteries, generic controllers, and unverified LEDs.

Always ask for:

• Component datasheets
• Brand names (e.g., LG, CATL, Philips)
• Certifications (CE, RoHS, ISO, IP65/IP67)

I once reviewed a supplier spec sheet that claimed “high efficiency LEDs”—but the diodes were 70lm/W at best. That’s a big red flag.

7: Installation Is Not Always Plug-and-Play

You might think it’s as easy as bolting the light to a pole—but installation mistakes can ruin performance.

Improper tilt angle, shadowed solar panels, or mismatched pole heights cause undercharging and poor lighting.

Installation tips:

• Ensure panel faces true south (or north in southern hemisphere)
• Avoid shading from trees or buildings
• Use correct tilt angle for your latitude
• Confirm pole and boom height matches the beam angle

A proper site survey before installation is a must.

8: Limited or No After-Sales Support

What happens if the controller fails in 6 months? Or you need replacement batteries?

Many suppliers offer no local service, limited warranties, and poor documentation.

Before you buy, confirm:

• Warranty period (preferably 3–5 years)
• Response time for support issues
• Availability of spare parts
• Clear troubleshooting manuals

Trusted brands offer remote diagnostics, firmware updates, and tech support—especially important for public infrastructure.

How to Choose a Trustworthy Supplier

Skip the flashy marketing. Here’s what really matters:

✅ Offers full technical documentation
✅ Uses branded components (LiFePO₄, MPPT, LED)
✅ Customizes based on local sunlight data
✅ Provides installation support + user training
✅ Shares case studies or verified project references

Look for suppliers who are willing to say “no”—if your site isn’t a good fit for their product, they’ll tell you. That’s how you know they’re honest.

Conclusion: Ask the Right Questions Before You Buy

Solar street lighting can be a smart, sustainable investment—but only if the system is properly designed and built.

Don’t fall for exaggerated specs or generic hardware. Ask detailed questions, demand transparency, and work with suppliers who care about real-world performance—not just the sale.

FAQs

What should I check before buying solar street lights?

• Battery type and capacity
• Solar panel wattage
• Lighting autonomy (backup days)
• Certifications (CE, RoHS, IP65)
• Warranty and after-sales support

Are all-in-one solar lights reliable?

Not always. While convenient, they can suffer from heat buildup and are harder to maintain. Split-type systems are often more durable and serviceable.

Why do some solar lights stop working in winter?

Undersized panels and weak batteries can’t store enough energy during short, cloudy days. Lack of autonomy planning is the usual cause.

What battery is best for commercial solar lighting?

LiFePO₄ (Lithium Iron Phosphate) batteries offer long lifespan, high cycle efficiency, and great performance in varying temperatures.