PoE Lighting vs Traditional Mains LED — a UK electrician's comparison guide

PoE lighting and traditional mains LED look similar on a finished ceiling. The differences are in the wall behind the ceiling and in the certification documents at handover.

A traditional mains LED installation delivers 230 V AC to every luminaire through standard fixed wiring. Each fitting contains a driver that converts the mains supply to the constant current or constant voltage required by the LED engine. The entire system is a Low Voltage (LV) installation under BS 7671:2018+A4:2026. Circuits sit on dedicated MCBs or RCBOs; testing follows the standard initial verification sequence.

A PoE lighting installation does something fundamentally different. A centralised PoE switch, fed from a mains supply in a comms cabinet, delivers DC power and Ethernet data to each luminaire through a single Cat 6 or Cat 6A patch lead. Each luminaire is an IP-addressable endpoint with its own MAC address, drawing typically between 5 W and 90 W from the switch port. Each circuit is Extra-Low Voltage (ELV), bringing it under Section 715 of BS 7671:2018+A4:2026 rather than the LV chapters.

Headline capex is the first question every client asks. The honest answer is that PoE is more expensive at the point of purchase, but the comparison is rarely apples-to-apples. The mains LED bill of materials does not always include the controls, daylight sensors, occupancy detection and BMS interface that come built into a PoE specification — and once those are added, the gap narrows.

On a typical 50-fitting open-plan office floor, capex pricing in 2026 sits at roughly £18,000-£25,000 for PoE against £12,000-£17,000 for an equivalent mains LED scheme with separate occupancy and daylight controls. The PoE premium reduces to around 5-15% once the mains scheme is brought up to the same control granularity.

Both technologies are far more efficient than fluorescent, halogen or incandescent — but PoE and mains LED do not produce the same lumens per watt at the meter once you include the power conversion chain.

A mains LED driver compliant with BS EN 61347 typically achieves 90-93% efficiency at full load, falling to around 82-88% at 20% dimming. A PoE installation introduces additional conversion losses: the switch power supply (around 92% efficient), the resistive losses in the data cable (typically 5-8 W per 90 m channel at 90 W loads), and the DC-DC step-down at the luminaire (around 95% efficient). Net efficiency at the LED engine is roughly 84-87%.

For Part L compliance under the Building Regulations, both systems can deliver the required lamp efficacy and control. The PoE energy premium at the cable is offset by superior controllability — clients chasing BREEAM Excellent or net-zero operational targets usually find PoE the easier route to evidence reduced operating hours.

Installing PoE lighting is not "harder" than mains LED — it is different. Mains LED installation uses the toolkit any qualified UK electrician already holds: 18th Edition (BS 7671:2018+A4:2026), 2391-52 inspection and testing, plus the ECS gold card competence required by most main contractors.

PoE lighting installation pulls in skills traditionally associated with data and structured cabling: TIA-568B termination, BS EN 50173 channel certification, IP addressing fundamentals, and switch configuration. A team that has never terminated Cat 6A to a certified standard will lose money on the first project. Equally, a data installer who has never sized cable for a Section 715 ELV circuit will get the supply side wrong.

1. Mains LED — single trade, single competency set, single certification regime.
2. PoE lighting — typically a joint scope between electrical (mains supply to comms cabinet) and data (structured cabling, switch commissioning, channel certification).
3. Hybrid teams — increasingly common: electricians upskilled in data cabling, or data installers competent to install up to ELV under Section 715.
4. Commissioning — PoE adds a software commissioning phase (zone mapping, occupancy logic, daylight calibration, BMS handshake) that has no equivalent in mains LED.

The single biggest regulatory difference between PoE and mains LED is the chapter of BS 7671:2018+A4:2026 that governs the installation. This affects how you design the circuits, how you protect them, how you test them, and what document you hand to the client at the end.

Traditional mains LED falls under the full body of BS 7671:2018+A4:2026 — Parts 4 (protection for safety), 5 (selection and erection), 6 (inspection and testing), and the various special location sections where they apply. Circuits sit on MCBs or RCBOs, are subject to RCD protection requirements (including the A4:2026 expansion of RCD scope for luminaires in certain locations), are tested for continuity, insulation resistance, polarity, earth fault loop impedance and RCD operation, and are recorded on a standard Electrical Installation Certificate.

PoE lighting from the switch outwards is Extra-Low Voltage (ELV) and falls under Section 715 of BS 7671:2018+A4:2026 (Extra-Low Voltage Lighting Installations). Section 715 sets out the requirements for SELV or PELV systems used for lighting, including segregation from LV circuits, protection against thermal effects, and the safety isolation requirements for the source. The PoE switch must be a Class II or equivalent isolated source with SELV output, and the LV supply to the switch must be a properly designed and protected LV circuit in its own right.

Inspection and testing is where the difference between PoE and mains LED becomes most visible at the handover stage. The client receives different documents from different competent persons, with different test instruments, recorded on different forms.

A traditional mains LED installation is tested per BS 7671:2018+A4:2026 Part 6 using a multifunction tester (MFT). The competent person records continuity of protective conductors (R1 + R2), insulation resistance, polarity, earth fault loop impedance (Zs), RCD operating time and current, and prospective fault current. Results are recorded on the Schedule of Test Results that accompanies the Electrical Installation Certificate, and a periodic EICR will follow at the recommended interval (typically 5 years for commercial premises).

A PoE lighting installation is tested per BS EN 50173 using a structured cabling channel tester (commonly a Fluke DSX or equivalent). The competent person records insertion loss, near-end crosstalk (NEXT), far-end crosstalk (FEXT), return loss, propagation delay and delay skew across each channel. Results are recorded in a per-channel certification report. There is no periodic equivalent to an EICR — the system is monitored continuously by the switch itself, which raises alarms on link failure or under-voltage at the port.

1. Mains LED — MFT test, EIC issued, periodic EICR every 5 years.
2. PoE lighting — Cat 6A channel certification, per-channel report, no periodic re-test required (continuous self-monitoring).
3. Hybrid — the LV supply circuit to the PoE switch still needs MFT testing and an EIC entry. The ELV distribution is on the channel certification report.
4. Emergency lighting — central battery or self-contained emergency luminaires retain their own BS 5266 testing schedule regardless of the lighting technology in use.

For an FM provider, the absence of a periodic EICR-equivalent on PoE distribution is genuinely attractive — provided the structured cabling has been installed and tested correctly in the first place. A poorly certified channel that passes initial commissioning but degrades over time will still cause field failures, and there is no statutory periodic check to catch it.

The strongest commercial argument for PoE is software-defined zoning. In a mains LED installation, zoning is defined by the cable runs — changing which switch controls which row of lights usually requires re-running cables or re-wiring a DALI controller. In a PoE installation, every luminaire is an IP-addressable endpoint, and zoning is a software configuration.

One of the strongest long-term arguments for PoE is that the data cable to every fitting is, by definition, a data cable. That same cable can carry sensors, beacons, asset trackers and IoT devices that have not even been specified yet at the time of installation. A ceiling full of PoE luminaires is also a ceiling full of network drops, and that has commercial value to the client over the building lifetime.

PoE lighting is not a universal replacement for mains LED. It wins decisively in some applications and loses awkwardly in others, and a good specification depends on matching the technology to the building.

1. Open-plan office — high luminaire count, low per-fitting wattage (typically 20-40 W), strong demand for granular control and BMS integration, frequent zone changes. PoE wins on flexibility and integration.
2. Retail — variable scene requirements through the trading day, frequent re-merchandising, integration with footfall counters and asset tracking. PoE wins on software-defined scenes and IoT-readiness.
3. Education — frequent timetable changes, classrooms re-purposed between subjects, strong demand for daylight harvesting and circadian rhythm tuning for student wellbeing. PoE wins on flexibility and tunable white.
4. Hotels — guest room scene control, integration with key card systems and room booking, demand for tunable white. PoE wins on integration and per-room flexibility.
5. Co-working — constant re-zoning of floor plates as tenants come and go, demand for individual user app control. PoE wins on dynamic zoning.
6. Smart buildings — buildings being specified to BREEAM Excellent or net-zero operational targets where the value of per-fitting sensor data and post-occupancy evaluation justifies the capex premium.

For all the marketing momentum behind PoE, there are major application categories where traditional mains LED remains the correct choice — mostly high-wattage, harsh-environment, or single-supply applications where the PoE power budget runs out or the comms cabinet model does not fit.

The certification deliverable at the end of the job is one of the cleanest ways to explain the difference between the two technologies to a client. The paperwork is different, the competent persons are different, and the periodic obligations are different.

1. Mains LED — Electrical Installation Certificate (EIC) per BS 7671:2018+A4:2026, with Schedule of Inspections, Schedule of Test Results, and operations and maintenance information. Periodic EICR every 5 years (commercial) or 10 years (domestic).
2. PoE lighting — BS EN 50173 channel certification report per channel, plus an EIC or Minor Works Certificate for the LV supply to the PoE switch cabinet. No statutory periodic re-test on the ELV distribution.
3. Emergency lighting — BS 5266 commissioning certificate, with monthly function tests and annual full-duration tests recorded in the log book, regardless of the underlying lighting technology.
4. Fire alarm interface — BS 5839-1 documentation for any cause-and-effect with the lighting system, regardless of technology.
5. Operating manuals — a PoE handover should include the controls platform user guide, IP addressing plan and switch configuration backup. A mains LED handover includes the DALI controller configuration if controls are specified.

For a smart-home or higher-end residential PoE lighting scheme, see our smart home lighting installation guide for the integration and handover sequence at the domestic scale, where the BMS context shifts from FM provider to homeowner-facing control apps.

The honest answer to "PoE or mains LED?" is "what is the building, what is the budget, what is the client's appetite for technology, and what is the lifecycle plan?" The decision tree below is the framework most UK consultants are now using on commercial fit-out projects.

1. Building type — office, retail, education, hotel, co-working: lean PoE. Industrial, outdoor, hazardous area, heritage: lean mains LED.
2. Per-fitting wattage — 5-50 W comfortably on PoE; 50-90 W on PoE Type 4; above 90 W mains LED only.
3. Control requirement — granular per-fitting scene control, daylight harvesting, occupancy: PoE wins. Bulk on/off or simple presence detection: mains LED is sufficient.
4. BMS integration — required at fitting-level granularity: PoE. Required at zone level only: either technology works.
5. Future re-zoning — frequent: PoE. Stable layout: either.
6. Resilience requirement — central UPS for lighting continuity: PoE delivers this naturally. Designated essential lighting circuits: mains LED with central battery.
7. Capex constraint — tight budget, no controls scope: mains LED. Mid-range budget with full controls scope: PoE often pencils out cheaper than full DALI mains.
8. Skills available — pure electrical contractor with no data team: mains LED is the safer self-delivery. Hybrid electrical+data team or strong data subcontractor partnership: PoE viable.