Just found a mess at one of my Denver commercial clients. Xcel changed their TOU windows effective June 1st but the billing system kept applying the old schedule for the first two weeks of June. Client got charged peak rates during what should have been off-peak hours under the new A-3 schedule. Anyone else seeing issues with utility billing systems not updating TOU schedules promptly? This cost my client an extra $1,847 for just two weeks.
Xcel TOU schedule changed mid-billing cycle - how to catch this?
Carl, I've seen this with IPL here in Indianapolis. They updated their Schedule LGS-TOU in March but their billing system lagged by almost a month. The problem is most utilities don't have good internal controls to verify their billing systems match published tariffs. You need to get interval data and manually verify the TOU windows were applied correctly. Did you request the 15-minute interval data from Xcel?
Greg, yes I pulled the interval data. That's how I caught it. The timestamps show peak rate charges from 10 AM to 2 PM on weekdays, but the new A-3 schedule moved peak to 1 PM to 6 PM starting June 1st. Clear as day in the data. Xcel admitted the error but of course claims it was an "isolated incident." Right. I'm now pulling interval data for all my Colorado clients with TOU rates.
This is exactly why I always request interval data for the first few months after any TOU schedule change. Ohio Edison pulled the same stunt last year - updated Schedule TOU-GS in writing but their billing system was still using the old windows. Cost one of my Youngstown clients $2,300 before I caught it. The utilities act like it's no big deal but these "glitches" add up fast.
Jim's right about requesting interval data early. I caught We Energies here in Milwaukee with a similar issue in 2011. They changed their Cg-4 TOU windows but forgot to update their demand calculation logic. Customers were getting charged peak demand rates during off-peak hours. Filed complaints with the PSC and got refunds for six clients totaling over $15,000. Always document everything with screenshots and timestamps.
Linda, that We Energies case sounds familiar. Was that the one where they had the demand window offset by 2 hours? I remember reading about that in the trade press. Here in Nashville, NES is pretty good about TOU accuracy but I still verify every schedule change. The key is having a spreadsheet template that compares published tariff windows against actual billing timestamps. Makes the errors pop right out.
Ed, yes that sounds like the same We Energies issue Linda mentioned. I've started using a similar verification process. Create a pivot table from the interval data showing usage by hour, then overlay the published TOU windows. Any discrepancies in rate application become obvious immediately. Going to standardize this for all my TOU audits going forward.
Carl, that pivot table approach is smart. I use something similar but also graph the hourly rates charged versus the published schedule. Makes it easy to spot when billing systems apply wrong windows or rates. The visual really helps when presenting findings to clients and utility representatives. Xcel should definitely reimburse your client plus interest for their error.