Author: Huang Publish Time: 22-01-2026 Origin: Site
Municipal engineers, industrial operators, and property managers all face the same fork in the road: keep high‑pressure sodium (HPS) fixtures running or migrate to LED street lights. In 2026, the decision is about more than wattage. Standards for controls and dark-sky compliance have tightened, maintenance budgets are under strain, and stakeholders expect safer, more comfortable nighttime environments. This guide puts “Sodium street light vs LED” into practical terms so you can specify confidently and build a defensible 10‑year plan.
Scenario | Winner | Why it wins |
Citywide retrofit with a dark‑sky ordinance | LED | Full cutoff optics, BUG‑friendly distributions, and 3000K options align with dark‑sky principles; interoperable controls are available out of the box. |
Warehouse/campus prioritizing smart dimming and uptime | LED | Instant‑on, deep dimming, ANSI 7‑pin/Zhaga control readiness, and higher delivered lm/W reduce energy and truck rolls. |
Mixed‑use development prioritizing aesthetics and safety | LED | Higher CRI (70–80+ typical) and precise distributions improve visibility and visual comfort. |
Budget‑constrained, short‑term stopgap (1–2 years) | HPS maintenance | If capital is frozen, continuing targeted HPS maintenance can bridge to a phased LED plan. |
Efficacy and energy use: Typical delivered luminaire efficacy for modern roadway LED ranges around 120–160+ lm/W (varies by optic and drive current). Representative product families such as Cooper Streetworks Navion document packages in this band (see the Navion spec sheet examples showing 116–157 lm/W across distributions: Cooper Streetworks Navion spec sheet). By contrast, HPS lamp‑level efficacy of ~98–130 lm/W drops at the system level once optical and ballast losses are accounted for (e.g., Philips SON‑T series lists 98–130 lm/W at lamp level: Signify Philips SON‑T product page). In practice, LED retrofits often cut roadway kWh by roughly half at equal or better illuminance, with further savings possible from dimming.
Lifetime and lumen maintenance: LED luminaires commonly carry TM‑21‑backed L70 projections near or above 100,000 hours at standard ambients when properly driven and cooled; for example, Signify’s RoadStar and GreenVision Xceed families cite L70 around 93,000–100,000 hours depending on configuration (Lumec RoadStar spec sheet; GreenVision Xceed Gen2 datasheet). HPS lamps typically require relamping within 20,000–40,000 hours (Signify Ceramalux datasheet). Fewer service events translate to fewer night‑work truck rolls and better uptime.
Maintenance and reliability: HPS systems combine lamps, sockets, and ballasts that age on different cycles. LED consolidates light source and optics and adds surge protection options, leaving drivers and connectors as the primary service items over time. Cities that converted report substantial maintenance reductions alongside energy savings—for example, Seattle’s upgrade program documented energy cuts near 48% with reduced relamping burdens and outage complaints (program overview: Seattle City Light street‑lighting upgrades).
Color quality and visibility: HPS delivers low CRI (around 20–30) and an amber spectrum that can hinder color‑critical tasks (Philips SON‑T pages include CRI fields). Roadway‑class LEDs typically deliver CRI 70–80+ with controllable CCT (commonly 3000K or 4000K), improving object recognition and perceived safety when paired with good optics. DarkSky’s guidance favors warmer CCTs to balance comfort and skyglow (DarkSky Five Principles for Responsible Outdoor Lighting: DarkSky lighting principles).
Warm‑up and switching: HPS needs minutes to warm to full output and does not restrike instantly. LED is instant‑on and supports frequent switching and deep dimming for adaptive lighting and off‑peak operation.
Smart‑control readiness: In 2026, LED luminaires are frequently offered with ANSI/NEMA C136.41 7‑pin receptacles and/or Zhaga Book 18 sockets for pluggable control nodes and sensors. The DesignLights Consortium references the 7‑pin ecosystem in its LUNA technical guidance (DLC LUNA technical requirements), and Zhaga outlines the Book 18 interface for outdoor luminaires (Zhaga Book 18 overview). That interoperability underpins asset management, metering, dimming, and fault alerts. Legacy HPS heads generally lack this plug‑and‑play controls ecosystem.
Dark‑sky alignment: DarkSky guidance favors full shielding, low uplight, reduced high‑angle glare, and warmer CCT. BUG ratings used in ordinances derive from LM‑79 distributions analyzed per IES TM‑15 (Addendum A: IES TM‑15 BUG Ratings addendum). LED makes it straightforward to select full‑cutoff, BUG‑friendly distributions and 3000K CCT to satisfy local ordinances. Many older HPS optics emit more high‑angle light and cannot meet strict BUG limits without replacement.
Photometrics and uniformity: LED road optics (Type II–V variants) enable tighter uniformity ratios and better glare control than many legacy HPS heads. That translates to smoother light on pavement, fewer hotspots, and fewer complaints. Representative families such as Cooper Navion and Leotek GreenCobra publish IES files supporting these outcomes (Leotek GreenCobra product pages: Leotek GreenCobra GCM product page).
Retrofit complexity: Replacing HPS with LED is typically a head‑swap plus controls socketing. Key checks include pole/arm fit, voltage range (120–277V or 347–480V), surge protection, and photocontrol compatibility. Most projects avoid re‑pole work unless structural issues are discovered. Manufacturer spec sheets outline voltage and surge options (e.g., Cooper Streetworks families list ranges and SPD selections: Cooper Streetworks Galleon spec sheet).
Environmental profile: HPS systems contain hazardous materials that require careful disposal. LED luminaires avoid mercury and can cut energy‑related emissions substantially when appropriately specified.
Safety and perception: Beyond measured illuminance, white‑light LED can improve detection distances and facial recognition relative to HPS in many conditions. Crash‑rate outcomes vary by corridor and require local validation, but communities often perceive improved comfort with well‑designed LEDs at warmer CCTs.
Dimension | HPS (typical cobrahead) | LED street light (2023–2026 typical) |
Delivered efficacy (lm/W) | Lower due to ballast/optical losses despite lamp‑level 98–130 lm/W | Commonly 120–160+ lm/W depending on optic and drive current |
Lumen maintenance (L70) | Lamp relamping ~20k–40k hours | TM‑21‑projected L70 near/above 100k hours in many SKUs |
Maintenance cadence | Lamps/ballasts on differing cycles; group relamping common | Fewer truck rolls; driver/service modules over long intervals |
Color quality | CRI ~20–30; amber spectrum | CRI 70–80+; 3000K and 4000K options common |
Warm‑up/restrike | Minutes to full output; no instant restrike | Instant‑on; deep dimming and cycling supported |
Controls readiness | Photocells; limited interoperable options | ANSI 7‑pin or Zhaga Book 18 sockets; 0–10V/DALI; network controls |
Dark‑sky fit | Legacy optics often emit uplight/high‑angle glare | Full‑cutoff, low‑U/low‑G BUG ratings available; 3000K CCT |
Photometrics | Wider hotspots, less uniformity in many legacy heads | Engineered Type II–V distributions; improved uniformity/glare control |
Retrofit complexity | Ballast removal; check arm/pole, voltage | Head swap; verify receptacle, surge, voltage, drill pattern |
Environmental | Hazardous‑materials handling for lamps | No mercury; lower energy‑related emissions |
10‑year TCO outlook | Lower capex; higher energy/maintenance | Higher capex; substantially lower energy/maintenance; faster payback in most cases |
Municipal dark‑sky retrofit: Choose LED with full‑cutoff optics and 3000K CCT. You’ll align with dark‑sky principles that emphasize shielding and warmer spectra while improving uniformity and enabling future dimming (see DarkSky’s Five Principles: https://darksky.org/resources/guides-and-how-tos/lighting-principles/). Specify luminaires with documented BUG ratings derived via TM‑15 methods and add a standardized control receptacle for long‑term flexibility (DLC LUNA guidance referencing ANSI/NEMA C136.41 7‑pin: https://designlights.org/our-work/luna/technical-requirements/luna-v1-0/).
Warehouse or campus prioritizing smart dimming and uptime: LED wins on instant‑on behavior, high delivered lm/W, and interoperable control sockets. Pair luminaires with networked lighting controls to schedule dimming during off‑peak hours, apply motion‑sensing where appropriate, and capture fault alerts before complaints surface. The operational savings typically compound beyond energy alone.
Mixed‑use developer streetscape: LED’s higher CRI and precise optics help tenants and visitors feel more comfortable while maintaining ordinance compliance. Favor warmer CCTs, low‑glare optics, and full shielding to balance visual comfort with efficiency.
Budget‑constrained partial program: If capital is frozen, keep critical corridors lit by maintaining HPS while you design a phased LED rollout. Prioritize high‑impact roads and problem areas first, then expand as rebates and budgets allow. This approach captures a large share of savings early without overextending.
Rather than betting on a single price, build a transparent model you can tune by corridor or campus. Core inputs: fixture count, current HPS wattage, proposed LED wattage, operating hours per year, energy rate ($/kWh), maintenance truck‑roll cost, lamp/driver replacement intervals, expected control savings, and any rebates. A simple structure:
Annual energy cost = (Watts × hours/year ÷ 1000) × $/kWh × fixture count.
Annual maintenance cost = (expected service events/year × labor/material cost) × fixture count.
10‑year TCO = Capex (fixtures + install) + 10 × (annual energy + annual maintenance) − rebates.
Model a baseline (HPS keep) and an LED case with conservative dimming assumptions. Run a sensitivity on energy prices and labor rates; in most regions LED still wins decisively on 10‑year TCO, and payback commonly falls within a mid‑single‑digit year window when controls are leveraged. Note that rebate programs, tariffs, and labor vary by locale; document “as of 2026‑01‑23” for your assumptions and update before procurement. If you need a shorthand, remember the decision keyword here: Sodium street light vs LED often resolves to LED once you account for energy and maintenance at scale.
Verify pole and arm compatibility (tenon/arm diameter, drill patterns), fixture weight, and wind‑load limits; confirm structural integrity where corrosion is suspected.
Specify control interfaces up front: ANSI/NEMA C136.41 7‑pin or Zhaga Book 18 sockets, plus 0–10V or D4i as needed; match photocontrol or node type (see the DLC LUNA technical requirements for controls and receptacle guidance: DesignLights Consortium — LUNA technical requirements; and the Zhaga Book 18 overview for the smart interface: Zhaga Book 18 overview).
Select surge protection to match utility conditions (e.g., 10–15kV SPD options) and confirm driver voltage range (120–277V vs 347–480V) (see Signify GreenVision Xceed Gen2 datasheet for example SPD options: Signify — GreenVision Xceed Gen2 datasheet).
Rework photometric design for LED distributions (Type II–V), target uniformity ratios, and dark‑sky/BUG constraints; test 3000K vs 4000K for community fit (refer to the IES TM‑15 BUG Ratings addendum for BUG methodology: IES TM‑15 BUG Ratings addendum).
Pilot on representative blocks or lots and measure results at 6 and 12 months (illuminance spot checks, complaints, outage logs) before scaling; large city programs like Los Angeles documented multi‑million‑dollar annual savings post‑conversion (see the DOE SSL R&D Plan (Los Angeles conversion summary): U.S. Department of Energy — SSL R&D Plan).
A large reason “Sodium street light vs LED” favors LED in 2026 is standardized, field‑upgradable controls. The ANSI/NEMA C136.41 7‑pin locking receptacle adds four low‑voltage contacts to the line‑voltage three‑pin form, enabling dimming, sensing, and two‑way communication with compatible nodes—an approach emphasized in the DesignLights Consortium’s responsible outdoor lighting guidance (https://designlights.org/our-work/luna/technical-requirements/luna-v1-0/).
Zhaga Book 18 defines a compact 4‑pin socket and mating ecosystem for pluggable sensors and communication modules, often paired with D4i drivers for intra‑luminaire data exchange (https://www.zhagastandard.org/books/overview/smart-interface-between-outdoor-luminaires-and-sensing-communication-modules-18.html). The upshot is practical interoperability: you can specify a luminaire now and change the control node later without replacing the fixture head. For projects with long life cycles and evolving smart‑city plans, that flexibility reduces lock‑in risk and total ownership costs.
In most scenarios, yes. LED delivers higher system efficacy (see Cooper Navion examples above), instant‑on dimming, better color rendering, and standardized control interfaces, and it more readily meets dark‑sky requirements when specified with full‑cutoff optics and warmer CCTs (see DarkSky principles).
Energy reductions of roughly half are common at equivalent illuminance, with additional savings from controls. Large programs have reported multi‑million‑dollar annual savings alongside steep maintenance reductions (Seattle program overview: https://www.seattle.gov/city-light/in-the-community/current-projects/street-lighting-upgrades; Los Angeles DOE summary: https://energy.gov/sites/prod/files/2015/06/f22/ssl_rd-plan_may2015_0.pdf).
Yes, when specified with full shielding, low‑uplight distributions, and warmer CCT (often 3000K). BUG ratings derived per IES TM‑15/LM‑79 support ordinance compliance (TM‑15 addendum: https://www.ies.org/wp-content/uploads/2017/03/TM-15-11BUGRatingsAddendum.pdf).
Confirm mechanical fit (tenon/arm and drill patterns), driver voltage range, surge protection, and control receptacles. Redo the photometric layout rather than lumen‑matching; LED distributions behave differently from legacy HPS optics (see Zhaga/ANSI receptacle standards above).
LED. Instant‑on behavior, high delivered lm/W, and networked controls enable scheduling and occupancy‑based dimming that cut both energy and maintenance while improving uptime.
Disclosure: KEOU Lighting is our brand. For projects emphasizing visual comfort and straightforward installation, KEOU’s LED street and area offerings include COB‑based designs and anti‑glare optics options that can support uniform illumination and simpler servicing. Explore the portfolio at the Street Light category page.
Internal reference: KEOU Street Light overview — https://www.keouled.com/street-light
DesignLights Consortium — LUNA Technical Requirements and glossary entries describing ANSI/NEMA C136.41 7‑pin controls and responsible outdoor lighting principles (accessed 2026) — https://designlights.org/our-work/luna/technical-requirements/luna-v1-0/
Zhaga Consortium — Book 18 overview of the smart interface between outdoor luminaires and sensing/communication modules, including Zhaga‑D4i interoperability (accessed 2026) — https://www.zhagastandard.org/books/overview/smart-interface-between-outdoor-luminaires-and-sensing-communication-modules-18.html
DarkSky International — Five Principles for Responsible Outdoor Lighting and street‑lighting guidance emphasizing shielding and warmer CCT (accessed 2026) — https://darksky.org/resources/guides-and-how-tos/lighting-principles/
IES TM‑15‑11 BUG Ratings (Addendum A) — framework for Backlight, Uplight, and Glare classifications used in ordinances (accessed 2026) — https://www.ies.org/wp-content/uploads/2017/03/TM-15-11BUGRatingsAddendum.pdf
U.S. DOE SSL Plan — Los Angeles LED street‑light conversion summary with reported energy and cost savings (2015 reference, accessed 2026) — https://energy.gov/sites/prod/files/2015/06/f22/ssl_rd-plan_may2015_0.pdf
Seattle City Light — Street lighting upgrades and savings notes reporting energy and maintenance reductions (accessed 2026) — https://www.seattle.gov/city-light/in-the-community/current-projects/street-lighting-upgrades
