Working on an audit for a manufacturing client in Duluth on Minnesota Power's Rate 31. The interval data seems to be showing on-peak charges during what should be off-peak hours according to the tariff schedule. On-peak is supposed to be 10 AM to 8 PM Monday through Friday, but I'm seeing peak rates applied at 9:30 PM on weekdays. Has anyone else noticed timing issues with MP's interval billing? Could be a daylight saving time problem or meter programming error. This is affecting about $3,200 in monthly charges.
Minnesota Power TOU Rate 31 - interval data showing wrong time periods?
Carl, I haven't worked with Minnesota Power but I see this kind of thing with PPL here in Pennsylvania. Usually it's either a meter clock issue or the utility's billing system is using the wrong time zone settings. Have you checked if the meter timestamps match the actual local time? Sometimes the meter is set to UTC and the billing conversion gets messed up. I'd definitely challenge those charges and request a detailed explanation of their time-of-use calculations.
This sounds familiar. I had an issue with Duke Energy Ohio where their interval data was showing peak periods extended by 30 minutes due to a billing system glitch. The meter data was correct but their TOU calculation software had an error. It took three months to get it resolved but we got full credits for the overcharges. Document everything and demand they provide you with the exact algorithm they're using for TOU period determination.
I work with Idaho Power and we've seen similar timing issues, especially around daylight saving transitions. The key is to get the raw interval data directly from the meter if possible, not just the utility's processed billing data. Compare the actual timestamps with what the utility is using for rate calculations. If there's a discrepancy, you've got them dead to rights. Idaho Power had to credit one of my clients $4,800 for exactly this type of error.
Update on Carl's situation - I just had the same issue with a Dayton Power & Light customer last month. Turns out DP&L had a software update that incorrectly shifted their TOU periods by 30 minutes for certain rate schedules. They issued credits going back 6 months once we provided the evidence. Carl, definitely push Minnesota Power for a complete audit of their TOU calculations. This might be affecting multiple customers, not just yours.