LED Street Light Wattage Guide: Lumens & Spacing
· NEON team
Choose the right LED street light wattage: lumen output by road type, pole height, spacing rules and how wattage changes unit price.
Wattage is the worst way to specify a street light and the way almost everyone specifies one. Two 100W fittings from different suppliers can differ by 40% in delivered light. This guide covers what to specify instead, and how to translate a road requirement into a wattage band you can actually buy.
Start from lux, not from watts
Road lighting standards are written in lux (illuminance on the surface) and uniformity (the ratio between the brightest and dimmest points). A typical municipal spec will read something like “average 20 lux, uniformity 0.4” for a residential collector road. Your job is to reach that figure, not to hit a wattage.
The relationship is roughly:
average lux ≈ (lamp lumens × utilisation factor × maintenance factor) / (spacing × road width)The utilisation factor depends on the light distribution and the pole position; the maintenance factor accounts for dirt and lumen depreciation over the service interval.
Wattage bands by road type
These are practical starting bands for LED street lighting at common pole heights, assuming a reasonably efficient fitting:
| Road type | Typical pole height | Typical spacing | Practical wattage band |
|---|---|---|---|
| Residential access / footpath | 4–6 m | 20–25 m | 30–60 W |
| Residential collector | 6–8 m | 25–30 m | 60–100 W |
| Commercial / distributor | 8–10 m | 30–35 m | 100–150 W |
| Arterial road | 10–12 m | 35–40 m | 150–250 W |
| Highway / interchange | 12 m+ | 40–50 m+ | 250–400 W |
Treat these as a starting point for a design, not as a substitute for one. A residential street with 8 m poles and 40 m spacing will not reach its lux target at any sensible wattage — the problem there is spacing and pole height, and buying bigger fittings to compensate produces glare and poor uniformity rather than good lighting.
Lumens per watt is the number that decides your unit price
Efficiency (lm/W) is what you are really buying. A 150 lm/W fitting delivering 20,000 lm needs about 133W; at 100 lm/W the same output needs 200W. That difference shows up as:
- A smaller driver and smaller heat sink — lower unit cost
- Lower electrical load across the scheme — smaller cable, smaller supply, lower running cost
- Fewer fittings or wider spacing to reach the same lux figure
When comparing two quotations that differ substantially in price, compare lm/W and warranty before comparing wattage. A cheaper fitting running at 90 lm/W is often the more expensive option once cable, supply capacity and energy are priced in.
Three specification traps
1. Nominal wattage versus actual consumption. Verify with a meter. A “100W” fitting drawing 85W is not a bargain; it is an under-delivering product that will come back as a complaint.
2. Beam distribution, not just beam angle. A symmetric 120° distribution and an asymmetric road-optimised distribution at the same angle produce very different road lighting. For street lighting, ask for the IES/LDT photometric file and run it in Dialux or AGi32 — this is what the file is for.
3. Colour temperature consistency. Mixed CCT across a road is the most visible defect in a completed scheme. Specify one CCT for the whole order and ask the supplier to confirm it holds across all units in the shipment.
Voltage and driver quality
A wide-input AC 85-265V driver tolerates the voltage sag common on weaker grids. If your project is in an area with unstable supply or heavy motor load, this matters more than a 5% efficiency difference — drivers are the single most common point of failure in field returns.
Ask which driver brand is fitted. It is a legitimate question and the answer is informative.
How this maps to a quotation
When you send an inquiry, include the road class, pole height, spacing, target lux level and the destination country. With those five figures we can recommend a wattage and distribution rather than quoting the nearest SKU in the catalogue — and if the layout as drawn will not reach the target, we will say so before you buy.
Products referenced in this guide
All-in-One Solar Street Light, 100W–3000W, IP65
All-in-one solar street light, 100W–3000W, DC 6V, IP65, 37,500–62,500 lm at 125 lm/W with remote control and dusk-to-dawn operation.
- MOQ 2 pcs
Moon Style LED Street Light, IP67, 60W–400W
IP67 street light with a 60W–400W module range, customised to your pole design for roads, highways, sidewalks and squares.
- MOQ 2 pcs