IOU · Iowa · EIA 9417
Interstate Power and Light Co
IOU · Iowa · 502K customers. According to the U.S. Energy Information Administration's EIA Form 861, reliability for 2023 shows SAIDI 149 minutes/customer.
Reliability verdict
Interstate Power and Light Co shows above-average chronic reliability in 2023: 88 minutes SAIDI excluding major events across 502K customers.
- 149 min
- SAIDI 2023
- 1.00
- SAIFI 2023
- 88 min
- SAIDI ex-MED
- 502K
- Customers
Chronic reliability judged on SAIDI excluding major event days when reported (IEEE 1366). Source: EIA Form 861 · August 2026.
Signature read: mid-cohort SAIDI between the 96 and 258 minute tercile cuts.
What mid-pack Interstate Power and Light Co filings show
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.
Based on this utility's own EIA Form 861 reliability record -- baseline (major-event- excluded) outage duration, total outage duration, and outage frequency -- each benchmarked against every reporting utility nationwide. Not a measure of electricity rates or customer service, which this portal does not track.
149 min/year per customer
Power-out minutes per year (2023)
SAIDI by year (2020-2023)
Minutes per customer-year · EIA Form 861
Year-by-year SAIDI for Interstate Power and Light Co from the same EIA filings as the table below. Lower is better; major-event years can spike the headline figure.
Interstate Power and Light Co SAIDI trend
Interstate Power and Light Co vs the nationwide SAIDI distribution
Where this utility's headline SAIDI sits among every EIA Form 861 utility with a reported figure
149 Lower than most fewer outage minutes than 53% of 911 utilities
Utilities nationwide, banded by latest reported SAIDI (minutes)
Each bar is a band; taller bars hold more utilities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source U.S. EIA Form 861 reliability filings · August 2026
Price vs. reliability
Where Interstate Power and Light Co sits on price vs. reliability
Among the 781 U.S. utilities large enough to report both revenue per customer and a recent outage record, Interstate Power and Light Co charges more per customer than 84% of them, and is more reliable (lower SAIDI) than 57% of them, placing it in the quadrant where it pays more and is more reliable. Revenue per customer and outage minutes are independent figures: paying more does not guarantee fewer outages.
Revenue per customer: $3,335/year · Latest SAIDI: 149.4 minutes/year.
SAIDI 2023 breakdown: 149.4 minutes
Reliability Trend (2020–2023)
| Year | SAIDI (min) | SAIDI nMED | SAIFI |
|---|---|---|---|
| 2020 | 3180.0 | 89.5 | 1.540 |
| 2021 | 107.4 | 74.1 | 0.820 |
| 2022 | 70.5 | 68.6 | 0.740 |
| 2023 | 149.4 | 88.2 | 1.000 |
SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.
Service Area
Interstate Power and Light Co serves 500 ZIP codes in Iowa.
Frequently Asked Questions
How reliable is Interstate Power and Light Co?
Interstate Power and Light Co had a SAIDI of 149.4 minutes in 2023. Excluding major weather events, this is below the national average, indicating above-average reliability.
What type of utility is Interstate Power and Light Co?
Interstate Power and Light Co is classified as a IOU serving Iowa.
How many customers does Interstate Power and Light Co serve?
Interstate Power and Light Co serves approximately 501,812 customers in Iowa.
How has Interstate Power and Light Co's reliability changed over time?
Interstate Power and Light Co has 4 years of reliability data (2020-2023). This utility's SAIDI has stayed fairly flat over the period. Review the trend table above for year-by-year detail.
Utility Profile
- Type
- IOU
- State
- Iowa
- Customers
- 501,812
- Annual Revenue
- $1.67B
- EIA ID
- 9417
Explore
Utilities with similar EIA profiles
Two cross-state peer sets for Interstate Power and Light Co. Same-state SAIDI neighbors stay in Read-with below; these neighborhoods are nearest other-state utilities with at least 10,000 reported customers.
Similar customer count
Nearest utilities by Form 861 customers (502K here), outside Iowa.
Similar chronic SAIDI
Nearest utilities by latest SAIDI minutes (149.4 here), outside Iowa, excluding the customer-peer set.
Source: U.S. Energy Information Administration Form 861 annual electric power industry survey · ZIP service territory: OpenEI. Disclaimer: informational only, not professional advice. See full disclaimer · methodology.