My client's Duke Energy Carolinas bill has 14 separate riders and surcharges. The base rate charges are about $8,000/month but the riders add another $3,200. That's 40% of the bill in riders. Is this normal? And how do I audit 14 separate rider rates?
How many riders is normal? Client has 14 separate riders on their bill
14 riders is on the high end but not unusual for Duke. Some utilities have accumulated riders over decades of rate cases. Each rider was created to recover a specific cost — fuel, environmental, grid modernization, storm restoration, nuclear decommissioning, etc. To audit them: pull the current rider schedule from the NCUC website, list the per-kWh or per-kW rate for each rider for your client's specific rate schedule, and compare to what's on the bill. It's tedious but methodical. I usually check the 5 largest riders by dollar amount first — those account for most of the rider charges.
When auditing riders, also check the effective dates. Riders change quarterly or annually. If the billing period spans a rider rate change date, the bill should prorate between old and new rider rates. I've found billing systems that apply the new rider rate to the entire period instead of prorating. Small per-bill error but it multiplies across every rider change.
Great advice from both. The 40% rider-to-base ratio is actually becoming the norm at many utilities. This means that rider errors can be more costly than base rate errors. I cannot emphasize enough: riders are not "set and forget." They change frequently and the billing system has to update for each change. Every update is an opportunity for error. Make rider verification a standard part of every audit. The 15-20 minutes it takes to check rider rates can uncover errors worth thousands.
Checked all 14 riders against the NCUC filing. Found one error — the storm cost recovery rider was at the residential rate instead of the commercial rate. Difference: $0.0034/kWh on 180,000 kWh/month = $612/month overcharge. One rider, one wrong rate table. Exactly what you described.