Auditing a manufacturing plant in Charlotte on Duke Energy Carolinas. The tariff Schedule LGS says power factor penalties apply when power factor falls below 0.85. My client's power factor has been between 0.86 and 0.89 for the past year. No penalty should apply. But the bill shows a power factor adjustment every month. Called Duke and they said their system penalizes below 0.90 for LGS customers. I told them the tariff says 0.85. They said I'm reading the wrong version. How do I resolve this?
Power factor penalty language — tariff says 0.85 but utility enforces 0.90
Download the current tariff directly from the NCUC website — that's the official filed version that the utility is legally required to follow. Duke Energy's own website might have an older or newer version. If the NCUC-filed tariff says 0.85, that is the legal standard regardless of what the utility's billing system is programmed to do. I had this exact issue with AEP Ohio where the tariff said 0.85 but the billing system was set to 0.90. The filed tariff won. Got 18 months of improper power factor penalties refunded.
Derek is right — the tariff filed with the state commission is the controlling document. Print the relevant page from the NCUC tariff filing showing the 0.85 threshold, highlight the provision, and send it to Duke Energy's rate department with your claim for refund of all power factor penalties applied when the client's power factor was above 0.85. If Duke believes the threshold was changed to 0.90, they need to produce the NCUC order approving that change. If no such order exists, the original 0.85 threshold is still in effect and every penalty charged between 0.85 and 0.90 is an overcharge.
Pulled the tariff from the NCUC docket search. It clearly says 0.85 for Schedule LGS. No amendment changing it to 0.90. Filing the claim with the NCUC tariff page attached. My client has been penalized for 14 months with power factor between 0.86 and 0.89 — that's about $1,100/month in improper penalties. $15,400 recovery coming.