I'm looking at a CL&P account in Hartford and seeing some bizarre interval readings. Customer is on Rate 34 (large general service) and every Tuesday at exactly 2:15 PM there's a massive spike - like 400 kW over their normal baseline. This has been going on for 6 months. The customer swears they're not doing anything different on Tuesdays. Anyone seen patterns like this before? Could be a meter issue but CL&P is dragging their feet on investigation.
Weird spike in 15-min interval data - CL&P customer
Vince, I had something similar with a Duquesne Light customer last year. Turned out to be an automated system that was programmed to run maintenance cycles. The facility manager didn't even know about it because it was set up by the previous tenant. Check if there's any building automation or HVAC scheduling that might kick in on specific days. Those 15-minute intervals don't lie - something is definitely drawing that power.
Walt's right about automated systems. I see this all the time with Georgia Power accounts. Could also be a data logger or energy management system that's been configured incorrectly. Have you tried correlating the spikes with other intervals throughout the week? Sometimes there's a pattern that only shows up when you look at the full month of data. Also worth checking if the spike corresponds to peak demand periods - that could cost them serious money on their capacity charges.
This sounds like a classic case where the customer needs to do some serious load monitoring on their end. I've seen MLGW customers get hit with massive demand charges because of mystery spikes like this. The 15-minute intervals are showing you exactly when it happens - now you need to figure out what equipment is running at 2:15 PM every Tuesday. Could be as simple as a water heater timer or as complex as manufacturing equipment on a weekly cycle.
Great suggestions everyone. I contacted the customer and had them do a walkthrough at exactly 2:15 PM this Tuesday. Turns out it was a compressed air system that was programmed to run a full regeneration cycle every Tuesday afternoon. The maintenance crew set it up months ago and never told management. The customer is now looking at rescheduling it to off-peak hours. This is exactly why I love interval data analysis - it tells the real story.
Nice detective work Vince! This is a perfect example of why we need to educate customers about reading their own interval data. Most of them have no idea what's actually driving their demand charges. I had a similar case with a TVA customer where mystery spikes were costing them $800/month in unnecessary demand charges. Once we identified the pattern and shifted the load, they saved over $9,000 annually.
Ed makes a great point about customer education. Here in Youngstown with FirstEnergy, I always provide clients with simple charts showing their demand patterns. Most people are visual learners - show them a graph of their 15-minute intervals over a month and suddenly those spikes make sense. It's worth the extra effort because it helps prevent future issues too.
Exactly Jim! I created a standard template that shows interval data in an easy-to-read format. Color-coded peaks, off-peak periods, and demand thresholds. Customers love it because they can actually see where their money is going. Plus it makes our job easier when they understand what we're trying to accomplish with load management strategies.