Large manufacturing client switched from CL&P Rate 57 to Rate 65 mid-month in October. The proration calculation was completely wrong - they used the wrong demand values and applied the old rate to the entire month instead of prorating by days. Customer got hit with $15,847 in excess charges. Anyone else dealt with CL&P proration errors on rate changes? This seems systematic.
Proration error cost client $15K - Connecticut Light & Power
Vince, I've seen this with PSE&G in Jersey. They struggle with mid-month rate changes, especially on industrial accounts. The billing system doesn't handle demand charge proration correctly. You'll need to do the math manually and show them exactly where they screwed up. I've got a spreadsheet template if you need it.
This is exactly why I always verify proration calculations manually. Had similar issue with PG&E last year - $8,200 error on a hospital account. The problem is their billing systems assume the rate change happens at the beginning of the billing cycle, not the actual change date. File a formal complaint immediately.
Jennifer's right about the system assumptions. APS here in Phoenix has the same issue. The key is getting the actual daily usage data and doing day-by-day calculations. For demand charges, you need to prorate based on the billing period days, not the demand measurement period. Pain in the ass but that's the only way to prove the error.
Thanks all. I've pulled the interval data and you're absolutely right - they applied Rate 65 demand charges for the full month when it should only have been 18 days. The daily energy charges were correct but demand was way off. Tony, would love that spreadsheet template if you can share it. This calculation is getting complex.
Vince, I'll email you the template. It handles demand charge proration for mid-month rate changes and works with most utility tariff structures. The key formula is (days on new rate / total billing days) × monthly demand charge. But watch out for minimum demand provisions - those can complicate the calculation.
Following this thread because we're seeing more rate change errors with Ameren Missouri. They just implemented new billing software and proration calculations are all screwed up. Vince, definitely push back hard on this. $15K is way too much to let slide. Document everything and reference the specific tariff sections on proration methodology.
Had exact same issue with Entergy New Orleans last month. Mid-month switch from Schedule LGS to Schedule LPS, they botched the demand charge proration. Took three months to get resolved but finally got $9,400 credit. Key was showing them their own tariff language about proportional billing. Don't give up!
This thread is gold. Just started seeing similar issues with Black Hills Energy here in South Dakota. New billing system went live in September and proration calculations have been disasters ever since. Vince, any update on your CL&P dispute? Would love to hear how it resolved.
Tom, still working through it but CL&P customer service finally acknowledged the error. They're saying 4-6 weeks for the credit to appear. The key was Tony's spreadsheet - showed exactly how the calculation should work versus what they did. Will post final resolution when I get it. Thanks everyone for the help!
Vince, great thread and glad to hear CL&P is fixing it. For anyone else dealing with proration errors, always request the detailed calculation worksheets from the utility. Most times they can't even explain how they did the math. That's usually when they realize there's a problem and start working toward resolution. Keep fighting the good fight!