Backup generator research

Outage duration (EIA). The Energy Information Administration publishes SAIDI (total minutes a customer is without power in a year) and SAIFI (number of interruptions). For 2024, all-events SAIDI was 662.6 minutes with SAIFI of 1.531; excluding major event days, SAIDI drops to 131.6 minutes with SAIFI of 1.065. Earlier in the series, 2022 all-events SAIDI was 333 minutes and 2023 was 366.6 — 2024 was a notably bad year, driven by major events.

Where you live dominates. EIA reported that in 2022, customers in Florida, West Virginia, Maine, Vermont and New Hampshire experienced the most interrupted power, ranging from an average of 10.3 hours in New Hampshire to 19.1 hours in Florida, while DC, Delaware, Rhode Island, Nebraska and Iowa ranged from 34 minutes in DC to 85 minutes. The national average is close to meaningless for an individual buying decision.

Carbon monoxide fatalities (CPSC). In its rulemaking record, CPSC documented at least 1,332 CO-related consumer deaths involving portable generators from 2004 through 2021 — an average of about 74 a year — plus thousands of non-fatal poisonings per year. Across 2017–2019, the figure averaged 85 deaths a year. CPSC also notes portable generator CO emission rates are on the order of hundreds of times those of gasoline cars.

Why the safety standards aren't a full fix. CPSC's testing of generators compliant with the current voluntary standards found that units run in an attached garage with the bay door fully open still produced CO concentrations in the living space sufficient to injure occupants, in some cases without triggering the generator's own shutoff. That finding is the reason the placement rule is 20 feet outdoors and not "somewhere ventilated."

How to choose

Look up your state, not the national average

State averages in 2022 ranged from 34 minutes to 19.1 hours. That spread is the whole decision.

Separate storm outages from routine ones

EIA's with- and without-major-events figures differ by a factor of five in 2024. Backup power is mostly a storm product.

Treat CO risk as a design constraint, not a warning label

The 1,332 documented deaths from 2004–2021 are overwhelmingly about where the generator was placed.

Check the year on any statistic you're quoted

2024 was a bad outage year at 662.6 minutes; 2022 was 333. A salesperson quoting only the worst year is cherry-picking.

Prefer primary sources

EIA and CPSC publish this data directly. Contractor marketing that cites no source should be discounted.