Quick answer
Grid Outage A grid outage is a loss of electricity from the utility grid to homes and businesses, from a brief flicker to days without power. Utilities track it with two numbers: how many times customers lose power (SAIFI) and how many minutes in total (SAIDI).
For a solar home, an outage matters because a standard grid-tied system turns off with the grid. Only a battery or another backup source keeps power flowing.
Quick facts
The key facts about grid outage, with sources:
- US average time without power, 2024
- 662.6 minutes, about 11 hours (SAIDI, IEEE, with major events) 2
- US average number of outages, 2024
- 1.531 per customer (SAIFI) 3
- Share caused by major events, 2024
- 80% of hours without power, mostly Hurricanes Beryl, Helene and Milton 1
- Typical year without major events
- About two hours per customer 1
- Highest state, 2024
- South Carolina, 3,155 minutes (nearly 53 hours) 2
- Generator CO deaths
- Nearly 100 a year in the US from portable generators 6
Key takeaways
- Most outage hours come from big storms; ordinary years average about two hours.
- In 2024, SC customers averaged nearly 53 hours without power, GA about 20 and VA about 16.
- Standard grid-tied solar shuts down in an outage, even on a sunny day.
- A battery with an islanding device, or a safely connected generator, keeps power on.
- Never run a portable generator indoors or in a garage.
What counts as an outage
An outage is any time the utility stops delivering power to your meter. A blink of a second or two is a “momentary” interruption. Utilities count the longer, “non-momentary” ones in their outage statistics.
The EIA reports two standard measures. SAIDI is the total minutes the average customer was without power in a year. SAIFI is how many times that happened 2. A third, CAIDI, is the average length of one outage.
Utilities also flag “major event days”. These are days when outage minutes far exceed the normal range, set by a formula in the IEEE 1366 standard 2. Storms create most of them.
Sources: [2]
How an outage reaches your house
- A fault: a tree limb on a line, wind, ice, flood, a failed part or a car hitting a pole
- Protective devices open to stop damage and fire
- Every home downstream of that device loses power
- Crews find the fault, make the area safe and repair it
- Power returns in stages, starting with the lines that serve the most customers
Types and causes of outages
| Type | Typical cause | Typical length |
|---|---|---|
| Momentary | A brief fault that clears itself, such as a branch brushing a line | Seconds |
| Routine sustained | Vegetation, equipment failure, animals, vehicle accidents | Usually minutes to hours |
| Major event | Hurricanes, ice storms, severe thunderstorms, flooding | Hours to days |
| Loss of supply | A problem on the high-voltage transmission system | Varies |
| Planned | Scheduled maintenance, with notice | Usually hours |
Sources: [1]
Why grid-tied solar goes dark in an outage
Most home solar inverters are “grid-following”. They time their output to the grid’s signal. When that signal disappears or goes far out of range, the DOE says they disconnect and shut down 4.
That is deliberate. The interconnection standard IEEE 1547 requires inverters to stop feeding a dead grid, which protects line crews working on lines they expect to be off 5. The full story is on the grid-tied solar page.
Solar-plus-battery systems can keep running because they use inverters designed to work without grid support 4. An islanding device first cuts the home off from the grid, then the battery inverter forms a small local grid for the house.
Outage data for SC, GA and VA, 2024
| Area | SAIDI, all events | SAIDI, without major events | SAIFI, all events | SAIFI, without major events |
|---|---|---|---|---|
| South Carolina | 3,155 min (≈ 52.6 h) | 115.9 min | 2.368 | 1.198 |
| Georgia | 1,208.1 min (≈ 20.1 h) | 211.4 min | 2.104 | 1.244 |
| Virginia | 962.1 min (≈ 16.0 h) | 245.1 min | 2.238 | 1.641 |
| US total | 662.6 min (≈ 11.0 h) | 131.6 min | 1.531 | 1.065 |
Example: reading the table
Look at South Carolina. In a normal year without major events, its customers lose power for about two hours (115.9 minutes), a bit less than the US average 2. In 2024, Hurricane Helene pushed the all-events total to 3,155 minutes. At least 1.2 million SC customers lost power in that storm 1.
Virginia shows the other pattern. Its everyday outages are longer than the US norm (245.1 minutes) and more frequent (1.641 a year) 2 3. That points to many short, local outages rather than one huge storm.
The lesson for a solar buyer: decide if you are planning for frequent short outages or rare long ones. Short ones need little stored energy; long ones need much more. See battery backup duration for the maths.
Where to check outages for your home
- Your utility’s outage map, for live outages and restoration estimates.
- The EIA Electric Power Annual, for state SAIDI and SAIFI by year.
- Your own records: a battery or smart-meter app often logs every grid loss.
- Our outage statistics by state, for a plain-English summary.
What keeps power on, and what each gives up
Options
- Battery with islanding: silent, automatic, recharges from solar.
- Standby generator: runs as long as fuel lasts.
- Portable generator with a transfer switch: lower upfront cost.
- Battery plus generator: covers both short and long outages.
Trade-offs
- Batteries hold a fixed amount of energy; long cloudy outages drain them.
- Standby generators need fuel, servicing and outdoor placement.
- Portable generators need manual set-up and pose CO danger.
- Combined systems cost more and need careful design.
Limits of outage data
State numbers are averages. A rural home at the end of a long line can see far more outage time than a city home on the same utility.
Methods also differ. The EIA publishes figures by the IEEE method and by “any method”, and utilities not using IEEE set their own major-event rules 2. Compare like with like, and use several years, not one.
Sources: [2]
What outages cost a household, and what drives backup cost
For a home, outage cost is spoiled food, lost work time, hotel nights, and for some, medical risk. That cost rises with length, which is why one long storm outage matters more than many short ones.
Backup cost is driven by how much of the home you cover and for how long. A few critical circuits for a few hours is a small job; whole-home cover for days is a big one. We do not publish installed prices; see what drives solar and storage cost.
What happens to a solar-plus-battery home in an outage
- The grid fails. The islanding device senses it and opens, cutting the home off.
- The battery inverter starts powering the backed-up circuits.
- Solar restarts behind the islanding device and recharges the battery when the sun is out.
- When grid power is stable again, the device reconnects the home.
- The battery returns to its normal mode and refills to its reserve.
Installing an islanding device or transfer switch is work for a licensed electrician or installer, under a permit.
Getting ready before storm season
- Raise the battery reserve when a storm is forecast.
- Test that backed-up circuits actually stay on; ask your installer how to do it safely.
- Know which outlets are on backup and label them.
- If you own a generator, have it serviced and keep fuel stored safely.
- Install battery-powered CO alarms on every level, as CPSC advises 6.
Warning signs and when to call
- Downed lines: stay far away and call the utility.
- Flicker or partial power (some rooms dim): call the utility; it can damage equipment.
- Solar or battery did not switch over: call your installer after the outage.
- Burning smell or sparks at the panel or meter: leave and call 911.
Safety rule
CPSC: operate portable generators outside only, at least 20 feet from the house, and never inside a home, garage, basement, crawlspace or shed. Nearly 100 people die each year in the US from generator carbon monoxide 6.
Rules and standards
Measuring outages: IEEE 1366 (2003 or 2012 edition) defines SAIDI, SAIFI and major event days. Utilities report under it to the EIA on Form EIA-861 2.
Solar during outages: IEEE 1547 sets how inverters connected to the grid must behave, including stopping export to a dead line 5. Utilities write it into their interconnection rules.
Backup wiring: transfer switches and islanding devices are covered by the electrical code adopted where you live, checked by your local inspector.
Grid outage vs related terms
| Term | Meaning | Read more |
|---|---|---|
| Grid outage | Loss of utility power to customers | This page |
| Brownout | Lower voltage, not a full loss | Ask your utility |
| Islanding | A home or area running on its own power, cut off from the grid | Hybrid inverter |
| Battery backup | Stored power used when the grid fails | Battery backup |
| Grid resilience | How well the grid resists and recovers from outages | Grid resilience |
Misconceptions
- Myth Solar panels keep my lights on when the power goes out.
- Reality Standard grid-tied systems shut down. You need a battery with an islanding device 4.
- Myth Outages are mostly random equipment failures.
- Reality Most outage hours come from major events; in 2024 they caused 80% 1.
- Myth A generator in the garage with the door open is safe.
- Reality CPSC says never run one in a garage. Keep it at least 20 feet from the house 6.
- Myth My state’s average tells me my risk.
- Reality Averages hide big differences between streets, towns and utilities.
Outages in SC, GA and VA
All three states had above-average outage time in 2024: SC 3,155 minutes, GA 1,208.1 and VA 962.1, against 662.6 for the US 2.
In SC the cause was mostly one storm, Hurricane Helene 1. In VA, everyday outages run longer and more often than the national norm even without major events. Check your own utility’s record before sizing backup.
Does outage risk change your solar plan?
- Count how many outages you had in the last few years and how long they lasted.
- If they were short and rare, grid-tied solar without storage may be enough.
- If they were long or you rely on power for health or work, add storage or a generator.
- Pick the circuits you must keep on, then size the battery for your typical long outage.
- Ask installers to show how the system behaves in an outage, step by step.
Related guides
Questions about grid outage
Do solar panels work during a power outage?
Not on a standard grid-tied system. The inverter shuts down when the grid fails, to protect line workers and equipment. To use solar in an outage you need a battery or a special inverter with an islanding device that disconnects the home from the grid first.
What causes most power outages?
By hours, major weather events. The EIA found they caused 80% of US outage hours in 2024, led by Hurricanes Beryl, Helene and Milton. Day to day, trees touching lines, failed equipment, animals and vehicle accidents cause most of the shorter outages.
How often does the power go out in the US?
In 2024 the average customer had about 1.5 outages, totalling about 11 hours. Without major events, the average was about one outage and roughly two hours a year. Your own experience depends on your utility, your street and the weather.
What are SAIDI and SAIFI?
They are the standard outage measures. SAIDI is the total minutes the average customer is without power in a year. SAIFI is the number of times that customer loses power. Both come from utility reports to the EIA, under the IEEE 1366 method or the utility’s own.
How long were power outages in South Carolina in 2024?
South Carolina customers averaged 3,155 minutes without power in 2024, nearly 53 hours, the longest of any state. Hurricane Helene caused most of it, cutting power to at least 1.2 million SC customers. Without major events, the SC average was under two hours.
How long were outages in Georgia and Virginia in 2024?
Georgia customers averaged about 1,208 minutes (about 20 hours) and Virginia about 962 minutes (about 16 hours), per the EIA. Both were above the US average of about 11 hours. Virginia also had more frequent everyday outages than the national norm.
Is it safe to use a generator with solar panels?
It can be, if a licensed electrician installs a proper transfer switch or the battery system supports a generator input. Never plug a generator into a house outlet. CPSC says to run portable generators outside, at least 20 feet from the house, and never in a garage.
Why does my solar inverter turn off when the power flickers?
Inverters must ride through small disturbances but disconnect from long or large ones. A brief dip may make it pause and then restart after a set wait. If it trips often, ask your installer to check the settings and whether your utility has a voltage problem.
What should I do when the power goes out with solar and a battery?
Usually nothing; the system should switch over by itself. Turn off big loads you do not need to make the battery last. Check the app for charge level. If the battery did not take over, call your installer once it is safe.
Sources
- US EIA, Today in Energy: Hurricanes in 2024 led to the most hours without power in 10 years (1 Dec 2025), retrieved .
- US EIA, Electric Power Annual, Table 11.4: SAIDI values by state, 2014–2024, retrieved .
- US EIA, Electric Power Annual, Table 11.5: SAIFI values by state, 2014–2024, retrieved .
- US DOE Solar Energy Technologies Office, Solar Integration: Inverters and Grid Services Basics, retrieved .
- IEEE, IEEE 1547-2018: Interconnection and Interoperability of Distributed Energy Resources, retrieved .
- US CPSC, As Winter Storms Continue, CPSC Urges Families to Take Steps to Prevent Carbon Monoxide Poisoning and Fires (2024), retrieved .
Expert review
Written by the HyreSolar Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: State SAIDI and SAIFI copied from EIA Electric Power Annual Tables 11.4 and 11.5 (IEEE method, 2024); causes and storm figures from EIA Today in Energy; inverter behaviour from DOE and IEEE 1547; generator safety from CPSC. Hours are minutes ÷ 60, rounded.
Suggest a correction. We fix errors and say what changed.