Rocky Mountain Power here in Salt Lake City taught me an expensive lesson about seasonal rate changes. I was auditing a Schedule 6A commercial customer and found what looked like billing inconsistencies between summer and winter months. The energy charges seemed too high in summer and the demand charges didn't follow the pattern I expected. I spent three weeks building a case for $15,000 in overcharges and presented it confidently to both the client and RMP. Turns out RMP has different rate structures for summer and winter periods on Schedule 6A, and I had completely missed the seasonal transition dates in the tariff. The billing was perfectly correct. RMP was polite but I could tell they thought I was amateur. The client lost confidence in my work and I ended up not getting paid for that portion of the audit. Always check for seasonal rate variations before claiming billing errors!
Watch out for seasonal rate changes - cost me $15K in credibility
Connie, I feel your pain on this one. Nashville Electric Service (fed by TVA) has seasonal variations that caught me off guard early in my career. I was analyzing a Schedule GSA customer and couldn't understand why their demand charges jumped in June. I thought it was a billing error until NES explained their summer/winter rate differential. It wasn't as costly as your mistake but it was embarrassing. Now I always create a rate calendar for each utility showing all the seasonal transition dates. It's saved me from similar mistakes multiple times.
MLGW here in Memphis has some tricky seasonal variations too. Their Schedule E-2 has different demand charge structures for summer peak season versus the rest of the year. I caught myself making a similar mistake to Connie's but fortunately double-checked before submitting anything. The summer rates are significantly higher and the transition dates don't align with calendar seasons - they're based on MLGW's internal peak period definitions. It's easy to miss if you're not familiar with their specific tariff structure. Thanks for sharing this cautionary tale!