CPS Energy just filed their 2025 rate case here in San Antonio and the proposed changes to Schedule IS (Industrial Service) are significant. They're moving from a simple demand charge structure to a complex time-of-use demand system with four different demand periods. The transition provisions allow for grandfathering of existing contract demand arrangements, but only if customers file the proper paperwork within 90 days of approval. This is going to create audit opportunities for years to come.
CPS Energy 2025 filing - Schedule IS industrial rate changes
Angela, that sounds very similar to what we went through with Avista up here in Washington. The time-of-use demand structures are incredibly complex to implement correctly. I'd recommend starting audit work immediately when the new rates take effect. We found billing errors on 60% of affected accounts in the first three months of Avista's implementation. The most common issues were incorrect peak period assignments and failure to properly apply transition credits.
Ernest is right about the complexity. Down here in Florida, we had similar issues when FPL implemented their multi-period demand structure. The key thing to watch is how they define the demand measurement intervals. Are they using 15-minute, 30-minute, or hourly intervals? And are they consistent across all demand periods? I found a case where the utility was using different interval calculations for different time periods on the same account, which created $35,000 in overcharges over six months.
Angela, I'd be interested in collaborating on this since Memphis is relatively close to San Antonio. MLGW is watching the CPS Energy case closely for ideas on their own rate restructuring. The grandfathering provisions you mentioned are particularly interesting - those transition periods always create billing complexity that benefits experienced auditors. Have you identified which specific industrial customers will be most impacted?
Randy, the biggest impact will be on manufacturing facilities with steady baseload plus peak production periods. Think aerospace, automotive parts, and heavy machinery manufacturers. These facilities typically have demand patterns that don't align well with traditional time-of-use periods. I've already identified about 20 potential clients that will need immediate audit attention once the new rates take effect. The revenue opportunity is substantial.
Angela, make sure to review how CPS Energy handles demand charges for accounts with on-site generation or storage systems. National Grid up here in Rhode Island had major billing errors for these types of facilities during their rate restructuring. The billing system couldn't properly net out the on-site generation from the demand calculations, leading to significant overcharges. One solar-equipped manufacturing plant was overcharged $28,000 in four months.
Great point Anthony. San Antonio has a lot of solar installations, both commercial and industrial. CPS Energy's new tariff language around net metering and demand charge calculations is pretty complex. I can already see potential issues with how they'll handle battery storage dispatch timing and its impact on demand charges. This could be a major source of billing errors once implementation begins.
Angela, document everything during the transition period. Take screenshots of tariff language, save all utility communications to customers, and keep detailed records of any preliminary billing runs. FPL changed their implementation approach three times during our transition, and having that documentation was crucial for proving billing errors later. Some of my biggest recoveries came from discrepancies between what they promised and what they actually implemented.
Excellent thread everyone. This is exactly the kind of collaborative intelligence that makes AAUBA valuable. Angela, keep us posted on the CPS Energy implementation progress. The lessons learned from your experience will be invaluable for the rest of us dealing with similar rate restructurings across the country. These complex transitions are creating more audit opportunities than I've seen in years.