Found a nasty one at a Sacramento client's manufacturing facility. SMUD billed them on TOU-GS-2 schedule but somehow applied weekend rates during Monday-Friday operations from June through December 2011. Plant runs 6am-6pm weekdays with heavy motor loads during peak hours. Weekend rate is $0.08949/kWh vs weekday peak of $0.16230/kWh - sounds good right? Wrong! The weekend TOU windows don't align with their actual usage pattern. Calculated overbill at $18,200 so far. Anyone else seen SMUD mess up TOU window assignments like this?
SMUD TOU-GS-2 weekend rate applied during weekdays - $18K overbill
Jennifer that's bizarre. In Arizona we see APS occasionally apply wrong seasonal schedules but never seen weekend/weekday mix-ups that dramatic. Did you check if they had the customer flagged as some special industrial category? Sometimes utilities have weird override codes that trigger wrong rate applications. Also worth checking if the meter data itself shows correct interval timestamps - could be a data processing error upstream.
Sarah's right about checking meter timestamps first. Here in Dallas with Oncor territory we had TXU Energy apply wrong TOU periods because the meter was programmed with incorrect DST transitions. Six months of bills showed peak periods shifted by one hour. Similar dollar impact - manufacturing client got hit hard during what should have been off-peak hours. ERCOT interval data confirmed the utility error. Document everything with 15-minute interval exports if you have them.
Marcus brings up good point about DST. IPL here in Indianapolis had systemic issues with TOU schedule E-32 applications during spring 2011 transitions. What's your client's actual meter read schedule Jennifer? If they're on monthly reads vs daily AMI that could explain delayed detection. We usually catch TOU errors within 2-3 billing cycles when we have access to interval data feeds. $18K suggests this went unnoticed for months.
Similar issue up here with PSE Schedule 40 last year. Large retail client got billed weekend TOU rates Monday-Wednesday for four months. Utility blamed it on system upgrade that corrupted customer class codes. The weekend rate structure actually cost them more because their usage peaks Tuesday-Thursday. PSE credited back $22,400 once we provided detailed interval analysis. Key was proving the meter data timestamps were correct but billing system applied wrong rate tables.
Thanks everyone for the insights. Confirmed the meter timestamps are accurate and DST transitions look correct. SMUD admitted they had a billing system glitch that affected about 200 TOU-GS customers in our service area. Client is getting full credit plus interest. David that's interesting about weekend rates actually costing more - we see that occasionally with clients who have unusual load patterns. Always important to verify the "error" is actually in the customer's favor before filing complaints!
Great catch Jennifer. Down here with MLGW we don't have as many TOU options but I've seen similar billing system errors after major software updates. The 200 customer impact David mentioned suggests this was a database update gone wrong. Utilities really need better QA processes when they migrate rate schedules. One question - did SMUD provide any documentation about their internal investigation or just the credit adjustment?