We've got a major dispute with Georgia Power on Schedule GSD-6 power factor penalties. They're billing us penalties based on 0.72 PF but our Fluke 435 consistently shows 0.89-0.91. The monthly penalty is running $2,800 which is killing our client's budget. Has anyone seen this kind of discrepancy before? We've requested meter testing but they're dragging their feet. The account is a 480V manufacturing facility in Marietta pulling about 850 kW average demand.
Georgia Power claiming 0.72 PF when our meter shows 0.89
Rachel, I've seen similar issues with Duke Energy here in Charlotte. Usually it's a timing issue between when they measure versus when your portable meter samples. Are you taking readings at the same time of day as their billing demand window? Also check if they're measuring at the service entrance versus downstream of your correction equipment. That 0.17 difference suggests they might be seeing uncorrected PF while you're measuring post-capacitors.
Derek's right about the measurement location. I had a similar case with IPL where the customer was reading PF after their automatic correction bank but the utility meter was upstream. Turn off your capacitors temporarily and take readings to see if you can replicate their numbers. If the discrepancy persists, demand a meter accuracy test per Georgia PSC rules. You're entitled to one free test per year on commercial accounts.
Good catch on the measurement point. We checked and sure enough, our readings were downstream of the cap bank. Disabled the correction equipment and immediately saw 0.74 PF on our meter. Still doesn't fully explain the 0.02 difference but it's much closer. Filed the meter test request yesterday. Georgia Power has 30 days to respond. Thanks for the help!
I'm dealing with TVA right here in Nashville on a similar issue. The key is documenting everything with time-stamped photos of both meters during peak billing periods. Also get a copy of their PF calculation methodology. Some utilities use a 15-minute rolling average while others use instantaneous readings at peak demand. Makes a huge difference in penalties.
Ed brings up a great point about calculation methods. JEA down here in Jacksonville uses 15-minute demand intervals but calculates PF penalties based on the single worst 15-minute period in the month, not average. Caught them doing this incorrectly on a hotel account and got 8 months of penalties refunded totaling $14,600. Always request their detailed calculation worksheets.
Update: Georgia Power completed the meter test and found their revenue meter was reading 0.03 low on reactive power measurement. They're issuing a credit for the past 6 months totaling $8,450. The corrected PF penalty is now only about $400/month which matches our calculations. Always worth pushing for that meter test!
Excellent outcome Rachel! That's exactly why we always recommend the meter accuracy test before accepting large penalty charges. Georgia Power actually has pretty good procedures for this compared to some utilities. Duke gave me grief for 3 months on a similar request last year.