Working on a Georgia Power GSA account here in Atlanta and I'm seeing some confusion in their billing. Customer has a 2.5MW load served at 13.8kV primary voltage through their own transformer. GP is billing them on Schedule GSA-P (primary) but I'm questioning if the metering setup is actually capturing the primary voltage properly. The discount shows as $4,200/month but the transformer losses seem to be double-billed. Anyone else run into this with Georgia Power? Their tariff language around customer-owned transformers is pretty vague on the metering requirements.
Georgia Power Schedule GSA - Primary vs Secondary Metering Question
Derek, I've seen similar issues with Duke Energy here in Charlotte on their Schedule LGS. The key question is whether the meter is on the primary or secondary side of the customer transformer. If it's metered on the secondary side but billed as primary, you're essentially getting charged for losses twice - once in the rate differential and once through actual measurement. Georgia Power should have engineering drawings showing the metering configuration. Request those first before challenging the billing.
Karen's right about the metering location being critical. Here in Chicago with ComEd, we see this all the time on their High Voltage Service tariff. If you're truly served at primary voltage, the meter should be upstream of your transformer and you should see the primary voltage discount. But if they're metering on the secondary side, you're paying for transformer losses that aren't really the utility's cost. I'd also check if Georgia Power is applying any power factor penalties correctly - sometimes they mess that up on primary service accounts.
This is exactly why I always request a site visit for primary voltage accounts. CPS Energy here in San Antonio has gotten better about this, but I caught them billing a client as secondary when they were clearly served at 13.2kV primary. The monthly difference was about $8,000. Derek, make sure you're also checking the demand calculation - primary service should exclude transformer losses from the billing demand if metered correctly.
Great thread, Derek. I deal with Georgia Power's Savannah territory and they've been pretty good about correcting these when you present the evidence properly. The GSA-P rate schedule specifically states that primary service must be metered at the primary voltage level. If your client's meter is downstream of their transformer, you have a solid case for reclassification. I'd recommend getting a load study done to show the actual transformer efficiency - usually runs 97-98% for modern units. That 2-3% loss difference times 2.5MW adds up fast.
Thanks everyone - this is exactly the insight I needed. I'm going to request the metering diagrams from GP and schedule a site visit. The transformer is a 2012 ABB unit so efficiency should be in that 98% range Lee mentioned. If we're looking at 50kW of losses being double-charged, that's substantial money over time. Will report back on what I find.
Definitely keep us posted, Derek. These primary/secondary classification issues are more common than people think, especially with customer-owned transformers. Good luck with GP!