Dear Reader:

One of the most important indicators of an LED lighting fixture’s energy efficiency is its Power Factor rating. While the meaning of this metric eludes some Facilities Managers, it’s really very simple as to what it means, and how it’s calculated.

Power factor is the measure of how much electricity is actually being converted to work – the creation of electric light. Looked at conversely, the electricity that is not being converted to lumen output, or footcandles down on the task area, is wasted consumption. For those particular electrons, you’re paying for kWh that is buying you nothing, so this portion of the electricity consumption is just flying out the door.

Every electrical device, machine, etc. loses some of its useful input energy to waste … the question is always, then, ‘how much’. As power factor metric is typically expressed in terms of a percentage, a good power factor r...