When requesting interval data, should I ask for 15-minute intervals or hourly? I've been getting hourly but someone told me 15-minute is much more useful for identifying demand spikes. Is the extra granularity worth the bigger dataset?
Member Community
Enter your email to read this discussion
You're reading the AAUBA Member Forum — where Certified Utility Bill Auditors share case studies, tariff strategies, and industry insights.
Free to read. Enter your email to continue.
No spam. We'll send you one welcome email about CUBA certification. Unsubscribe any time.
15-minute vs hourly data — does it matter?
Always get 15-minute if available. Demand charges are typically based on the highest 15-minute or 30-minute demand interval in the billing period. If you only have hourly data, you're seeing an average across four 15-minute intervals. A demand spike that lasts 15 minutes and costs your client $2,000/month in ratcheted demand charges is completely invisible in hourly data because it gets averaged out. I had a cold storage facility on Xcel Energy where hourly data showed steady 400 kW demand but 15-minute data revealed a 15-minute spike to 680 kW every morning when all the compressors kicked on simultaneously. Staggering the startup sequence eliminated the spike and saved $3,100/month.
I agree — always request 15-minute data. The demand spike identification alone justifies the larger dataset. Most modern Excel versions handle 35,000 rows of 15-minute data (one year) without any problems. The other advantage of 15-minute data is that it lets you accurately model alternative rate scenarios. If you're evaluating whether your client should switch to a time-of-use rate, you need 15-minute data to calculate what their bill would have been under the TOU rate. Hourly data is too coarse for accurate TOU modeling because the on-peak and off-peak periods often start and end on the quarter hour.
Makes total sense. Switching all my data requests to 15-minute going forward. The cold storage example really drove the point home.