DALI drivers, emergency-test electronics, presence sensors, and standby controllers all draw power even when the LED is off. Per fixture: 0.5-3 W. A 1000-fixture office: 0.5-3 kW continuous, 24/7 = 4-26 MWh/year. EU EcoDesign now caps Pdrive at 0.5 W for many categories. KSA SASO is heading the same way. Spec it before buying.
Four ideas to carry into the next specification conversation you have.
Smart drivers, DALI controllers, emergency-test circuits all draw idle power.
Across a campus, this can be 1-5 kW continuously, a meaningful load.
Pdrive ≤ 0.5 W for most general LED categories. SASO is aligning.
Otherwise you can buy 1000 fixtures that quietly consume an extra 2 kW forever.
Typical Pno values by driver / controller type.
| Component | Off-state P (W) | Notes |
|---|---|---|
| Basic LED driver, no smart | 0.05-0.2 | Negligible |
| DALI-2 driver | 0.3-0.8 | Bus active |
| Casambi / Bluetooth driver | 0.4-1.2 | Radio active |
| Emergency self-test | 0.5-2.0 | Periodic mains check |
| Presence-sensor luminaire | 1-3 | Sensor + radio |
| EcoDesign cap (EU) | ≤ 0.5 | Most categories |
Five places where 1 W × 1000 fixtures adds up.
Lights off, but DALI bus + emergency monitors draw 1 W each × 800 fixtures = 800 W × 130 hours/week = 5.4 MWh/year.
Even a tiny 0.5 W per guestroom controller × 1000 rooms × 24/7 = 4.4 MWh/year, and that's just the controllers.
Motion + daylight sensors draw 1-2 W standby. 500 fixtures × 1.5 W × 24/7 = 6.6 MWh/year.
Self-test once a week + always-on monitoring electronics. 0.5-1 W × hundreds of fixtures.
PoE drivers have switching losses even when LED is dark. 1-2 W per port × 100 ports = 100-200 W constant.
All NLC commercial LED drivers are EU EcoDesign-compliant: Pdrive ≤ 0.5 W in standby. Across a 1000-fixture project, that's tens of MWh/year saved over standard drivers.
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