I've got a Duke Energy commercial customer in Cincinnati that just had their mechanical meter swapped for AMI last month. The first smart meter bill came in showing 40% higher usage than their typical monthly consumption. Customer is furious and calling it a scam. Has anyone else encountered dramatic increases like this after AMI deployment? The account is on Schedule SGS-3 and we're talking about a $3,200 increase over their normal $8,000 monthly bill. I'm wondering if the old mechanical meter was running slow or if there's calibration issues with the new AMI.
Duke Energy smart meter readings 40% higher than old mechanical - has anyone else seen this?
Cecilia, I've seen this exact scenario with Idaho Power AMI rollouts here in Boise. In about 15% of cases, the old mechanical meters were running 20-35% slow, especially on older commercial accounts that hadn't been tested in years. Your customer was probably getting a "discount" they didn't know about. Idaho Power actually has a reconciliation process for situations like this - they'll do a 12-month average adjustment if you can prove the mechanical meter was defective. Does Duke have something similar?
Warren's right about the slow mechanical meters. I had a similar case with Alabama Power where a restaurant's 30-year-old meter was running 45% slow. The AMI revealed their true consumption and the bill shock was severe. Alabama Power ended up doing a 6-month phase-in of the correct billing to help the customer adjust. The key is getting the utility to test the old meter if they still have it. Most utilities will do this for disputes over $1,000.
Thanks Warren and Albert. I contacted Duke and they still have the old meter. They agreed to send it for testing at their meter lab. The customer is also demanding interval data from the AMI to verify the readings are accurate. Duke says they can provide 15-minute interval data going back 35 days. Should I ask for longer history or is 35 days sufficient to establish a pattern?
Cecilia, get at least 60-90 days if possible. I've found that 35 days might not capture seasonal variations or equipment cycling patterns. Also, if this is a three-phase commercial account, make sure Duke provides interval data for all three phases. I've caught AMI systems where one phase CT was installed backward, showing negative readings that got corrected in the billing system but skewed the total consumption calculation.
Jack makes a good point about the CT installation. I've seen multiple cases with FirstEnergy here in Cleveland where the AMI installers crossed phase wires or installed CTs backwards. The meters would still read, but the power factor calculations were wrong, affecting demand charges. Always request the full installation work order and have them verify CT polarity if it's a high-dollar account.
Update: Duke tested the old meter and it was running 38% slow! They're offering a 12-month graduated adjustment where the customer pays 25% of the difference in months 1-4, 50% in months 5-8, and full rate thereafter. Customer accepted rather than paying the full back-billing amount. Lesson learned - always suspect mechanical meters on accounts that haven't been tested in over 10 years.
Great outcome Cecilia! That graduated adjustment approach is fair. For future reference, Duke also has a policy where they'll waive back-billing beyond 24 months if the meter error was over 30%. Might be worth noting in your files for similar cases. The key is documenting that the customer had no way to know about the meter malfunction.