Energy savings using LEP luminaires comes from a combination of source and application efficiencies
- LEP’s source efficacy, lumens created per watt consumed, is 15-20% higher than an HID source, because no power is wasted in heating electrodes. Plasma light source efficacy ranges from 115 to 150 LPW at operating temperatures.
- LEP sources can be utilized to achieve application efficiency more effectively than HID, induction lighting or LED because of its directionality and size. The directional source prevents light from being trapped inside a luminaire. Point source optics effectively maps the source to the illuminated area, preventing unwanted light spill (a source for glare and light-pollution).
Dimming (based on occupancy or demand response) further reduces energy costs, and actually lengthens the life of the plasma lamp beyond the rated lifetime.
Application Efficiency Comparison: HPS vs. LEP
|460W HPS||280W LEP||Benefit|
|Fixture Efficiency||65%||85%||Directional source|
|Light Loss Factor||75%||85%||Low lumen degradation|
|Mean Fixture Lumens||24,375||15,572|
|Application Efficiency||48%||82%||Optical control|