Grid reliability · 2024 · 13 reporting utilities

Power outages in Iowa

The utilities that reported here serve 904,873 customers between them, not the whole state. Weighted by customer count, they averaged 84 min without power in an ordinary year and 3.3 hr once major events are counted. Each figure comes only from the filers that published it, and the counts are below.

What it means

Why there are two numbers

Across the utilities that filed both figures, major events account for 58% of the outage time Iowa recorded once they are counted: 3.3 hr against 84 min without them, a factor of 2.4×. Solar panels alone do not help during an outage, because a grid-tied array shuts down when the grid does, so riding through one is a battery question. This figure will not answer it: it is an annual average across a utility’s customers, not the length or the load of any single outage. What it does say is how much of the outage time here arrives with major events rather than on ordinary days.

The comparison is drawn from the 13 utilities that filed both figures, which is all of them, so both sides of the ratio describe the same set of customers. The two headline figures above are averaged over everyone who filed each one, so dividing them would not give this number.

Ordinary year84 min39 of 51 jurisdictions, longest first · 13 filings

With major events3.3 hrStorms, ice, and fires included as filed · 13 filings

Interruptions a year0.8×Ordinary year; 1.2× with major events

The bill sideWhat solar offsetsRates and modelled output by utility

The utilities behind the average

Each of Iowa’s figures is a customer-weighted average of the filings that carried that metric, not of the table as a whole: the ordinary-year average is built from 13 filings and the storm-inclusive average from 13 filings, out of 13 filings that published an outage figure at all. Those are the same utilities on both sides. A utility that filed without publishing a metric, or whose two major-event variants contradicted each other, is absent from that metric rather than counted as zero.

Reported interruption metrics for 2024, largest utility first.
Utility	Customers	Ordinary year	With major events	Interruptions
MidAmerican Energy Co	740,347	88 min	3.6 hr	0.8×
Linn County REC	33,181	116 min	116 min	1.5×
City of Ames - (IA)	27,592	19 min	39 min	0.3×
Eastern Iowa Light & Power Coop	24,124	99 min	3.7 hr	0.9×
Maquoketa Valley Rrl Elec Coop	17,236	71 min	2.2 hr	0.8×
Iowa Lakes Electric Coop	13,237	45 min	45 min	0.5×
Board of Water Electric & Communications	11,665	9 min	41 min	0.2×
East-Central Iowa Rural Elec Coop	9,114	38 min	38 min	0.5×
Consumers Energy Coop - (IA)	7,560	96 min	8.2 hr	1.0×
MiEnergy Cooperative	7,262	60 min	69 min	0.6×
Heartland Power Coop	5,249	70 min	78 min	0.8×
Butler County Rural Elec Coop - (IA)	5,110	66 min	86 min	0.6×
City of Independence - (IA)	3,196	11 min	11 min	0.4×

What this page is not

It is a state average of utility filings, not a measurement at any address. Each filing is itself an average over a whole service territory, so a rural feeder and a downtown network arrive here as one number, and nothing in this dataset says how far an individual address sits from it. Nothing here predicts a future year either, and a single severe storm can move a utility’s figure by an order of magnitude.

The methodology page states the sources, the definitions, and the limits. Back to the Grid Reliability Index

Source: U.S. Energy Information Administration, Form EIA-861 reliability file, data year 2024, covering 2024-01-01 through 2024-12-31. The snapshot covers no later period.