Interstate Power and Light Co

What This Utility Data Tells You

Interstate Power and Light Co is an investor-owned utility operating in Iowa under EIA identifier 9417. It reports service to approximately 501,812 customer accounts and generated about $1.67 billion in annual electric revenue, with a service footprint spanning 500 ZIP codes. Because it is investor-owned, the state public utility commission oversees its rate cases and reliability performance rather than a local board.

In 2023, the average Interstate Power and Light Co customer experienced 149.4 minutes of power interruptions, the industry-standard SAIDI metric (System Average Interruption Duration Index). That places this utility well below the 120–180 minute national benchmark, signaling strong grid hardening and fast restoration practices. The SAIFI figure, which tracks average outage events per customer, came in at 1.00 for the same period, meaning customers statistically saw about 1 distinct interruption that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 88.2 minutes, the gap between that figure and the headline 149.4 reveals how much weather, not day-to-day infrastructure, drove outages.

The EIA dataset includes 4 years of continuous reporting (2020–2023) for Interstate Power and Light Co, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. Over that window, SAIDI moved from 3180.0 down to 149.4 minutes, a trend worth noting for anyone weighing capital investment outcomes. Note: this figure is unusually low compared to typical U.S. utility performance and may reflect an incomplete EIA filing for this year rather than a genuine reliability improvement -- treat with caution and cross-check against Interstate Power and Light Co's other reported years.