Client on AEP Ohio TOU rate. Their July 4th usage was billed entirely at the on-peak rate. The tariff clearly states that NERC holidays are treated as off-peak regardless of the day of the week. July 4th is a NERC holiday. This is a straightforward billing system error — the system didn't flag July 4th as a holiday. The overcharge for that one day was about $340. Small amount but I'm checking every holiday for the past 3 years now.
Utility billing on-peak rate during a holiday — tariff says holidays are off-peak
Check Thanksgiving, Christmas, New Year's, Memorial Day, and Labor Day too. The NERC holiday list is standard but I've seen billing systems miss individual holidays inconsistently — they'll correctly code Christmas as off-peak but miss Memorial Day. Also check if the tariff uses NERC holidays or a different holiday list. Some utilities define their own holiday schedule that differs from NERC.
Good catch. Holiday billing errors on TOU rates are more common than they should be. The billing system should automatically code holidays as off-peak but the holiday table in the system needs to be updated each year. Some utilities forget to update it. The dollar amount per holiday is small but multiply by 6-10 holidays per year over several years and it adds up. Always verify holiday treatment when auditing TOU accounts.
Checked all holidays for 3 years. Found 4 more holidays billed at on-peak in addition to July 4th. Total overcharge across all missed holidays: $1,870. Not huge but it's money the client is owed.