I've got a manufacturing client in Charlotte on Duke's Schedule LGS-TOU getting hammered with incorrect time-of-use charges. Their interval data shows usage being billed at on-peak rates during off-peak hours. Duke claims their system automatically adjusts for daylight saving time, but I'm seeing on-peak billing at 6 AM on weekends when the tariff clearly states off-peak. The overcharge is about $4,800 per month. Has anyone dealt with Duke's TOU clock synchronization issues? This started happening after they upgraded to the new AMI system.
Duke Energy Carolinas TOU billing errors - need advice
Derek, I've seen this exact issue with FPL's AMI rollout here in Florida. The problem is usually in the head-end system applying TOU periods, not the meter itself. Request the raw interval data file directly from Duke and compare it to your billing analysis. Often the meter records correct timestamps but the billing system applies wrong TOU periods. I caught FPL making a $12,000 monthly error this way for a client in Orlando.
Derek, MLGW had similar issues when they upgraded their interval data processing system. The key is getting Duke to provide the actual TOU schedule their billing system is using versus what's published in the tariff. Sometimes there are programming errors where holidays aren't properly coded or DST transitions aren't handled correctly. Document every billing period discrepancy and demand a formal rate schedule compliance audit. I've seen settlements over $50K for these systematic TOU errors.
Had a client with Duke Energy Ohio get billed on-peak rates for Saturday usage that should have been off-peak under Schedule DP. Turned out Duke's new billing system wasn't recognizing the customer's rate code properly and defaulting to a different TOU schedule. Once we got them to manually verify the rate schedule assignment, they corrected 8 months of billing errors totaling $22,400. Always verify the rate code in their system matches your contract.
Derek, check if Duke is using local time or UTC for the TOU calculations. CPS Energy here in San Antonio had a bug where they were applying Central Standard Time year-round instead of switching to Daylight Time. This created a one-hour shift in TOU periods during summer months. The error affected hundreds of customers before they caught it. Demand they show you exactly which time zone and DST rules their billing system is using for your account.
Thanks for all the suggestions. I requested the raw interval data from Duke and found the smoking gun - their system is applying TOU Schedule LGS instead of LGS-TOU. The base LGS schedule has different on-peak hours that don't include the weekend exemptions. It's a simple rate code error but it's costing my client almost $5K monthly. Filing a formal complaint with NCUC if Duke doesn't fix this immediately.
Derek, make sure you get documentation of when the error started. If it's been going on since the AMI upgrade, you might be entitled to retroactive billing corrections beyond the standard 2-year limit. MLGW had to go back 3 years for systematic billing errors when Randy and I worked a similar case. The key is proving it was a utility system error, not a customer billing dispute.
Bobby's right about the lookback period. Utility system errors often qualify for extended billing corrections under most PSC rules. Also check if other Duke customers on LGS-TOU are affected - this could be a class issue worth pursuing with the commission. Document everything and keep pushing for a complete audit of their TOU billing system implementation.
Update: Duke admitted the rate schedule coding error and agreed to correct 14 months of billing back to the AMI installation date. Total credit will be $67,200 plus interest. They're also auditing other LGS-TOU customers for the same error. Sometimes persistence pays off. Thanks everyone for the technical guidance - the UTC time zone question was particularly helpful in proving their system was flawed.
Excellent outcome Derek! $67K recovery is worth the fight. Make sure Duke provides written procedures for preventing this error in the future. Utilities hate admitting systematic billing problems but when you catch them red-handed with interval data analysis, they usually settle quickly to avoid regulatory scrutiny.
Derek, congratulations on the recovery! Question - did Duke provide any compensation for your audit costs? Some utilities will reimburse professional audit fees when they admit systematic billing errors. Might be worth asking for since you essentially found and fixed their billing system bug.
Great case study Derek. I'm dealing with a similar TOU issue with Duke Energy Progress here in Raleigh. Their interval data processing seems to have multiple bugs since the AMI upgrade. Mind sharing which specific documentation you requested from Duke? I want to make sure I'm asking for the right technical details to prove the billing errors.