LED lighting conversion tanked my client's power factor

Something weird happened. Client converted from fluorescent to LED lighting in their warehouse. Energy usage dropped 40% which is great. But their power factor went from 0.88 to 0.71 and now they have a massive PF penalty that nearly wipes out the lighting savings. How does switching to supposedly more efficient lighting make power factor worse?

This happens more often than people expect. When fluorescent lighting was the dominant load, the magnetic ballasts contributed a lot of reactive power but the total real power was high enough to keep the PF ratio reasonable. When you remove that large real power load by switching to LEDs (which draw much less real power), the remaining loads — motors, transformers, VFDs — now dominate the power factor calculation. The reactive power didn't change much but the real power denominator got a lot smaller, so the ratio (PF) dropped. The building always had poor power factor on its non-lighting loads — the fluorescents were just masking it.

Mike explained the physics perfectly. This is becoming a more common issue as LED retrofits proliferate. The audit takeaway: whenever a client does a major lighting retrofit, flag the potential PF impact. The client may need to add capacitor correction simultaneously with the lighting upgrade to avoid trading energy savings for PF penalties. For your current client, the fix is a capacitor bank sized to correct the non-lighting loads. The good news is that the same energy reduction from LEDs means the capacitor bank can be smaller and cheaper than it would have been pre-retrofit.

Makes total sense now. The LEDs didn't cause the problem — they revealed a pre-existing one. Recommending capacitor correction to the client alongside a PF penalty refund claim for the months before the caps are installed. Thanks for the explanation.