What if there were no electricity for a day?

Click! The lights go off. The fridge goes quiet.

The electricity has stopped. What if it stayed off for a whole day? Let's think about it together.

Electricity does so many jobs that we hardly notice it: it lights rooms, keeps food cold, charges phones and runs computers. Usually it is just there, every second of every day.

Sometimes, though, the power goes out for a while, often because of a storm. In this thought experiment, imagine the electricity in your town is off for a whole day. You can follow three paths: what happens at home, how the grid that brings electricity works, and how backup power keeps important places running.

An electric power outage is an interruption in the supply to customers, often caused by weather damage to power lines and other equipment. Utilities track how long and how often they happen.

This thought experiment imagines a 24-hour outage and asks three questions: what it means for a household, why a power grid can fail and how it is designed to stay reliable, and how places such as hospitals keep essential equipment running. Its outcomes are reasoned from today's systems and published guidance, not predictions.

Most days, the electricity never stops. Power cuts happen, but they do not add up to much time.

Not counting big storms, people in the United States have only about two hours without power in a year.

Electricity is made in power plants and travels to homes through the grid: high-voltage power lines for long distances, then substations with transformers that lower the voltage, then local lines to each street and house.

Power cuts are not common. The U.S. Energy Information Administration (EIA) found that power cuts not caused by big events such as major storms add up to about two hours a year for the average customer. Counting everything, the average in 2024 was 11 hours, nearly twice the yearly average of the decade before, mostly because of major storms such as hurricanes.

EIA describes the grid as substations, transformers and power lines connecting producers and consumers. High-voltage transmission lines make long-distance transport more efficient, and substation transformers step voltages up or down for each stage of the journey.

EIA's Electric Power Annual 2024 found U.S. customers averaged 11 hours of interruptions in 2024, nearly twice the previous decade's average, and major events such as Hurricanes Beryl, Helene and Milton accounted for 80% of those hours. Interruptions not caused by major events routinely average about two hours a year.

Let's pretend the power is off all day. The fridge stops. The lights don't work.

Families use flashlights. They keep the fridge door closed to keep the food cold.

Imagine waking up to a dark, quiet house. The fridge and freezer have stopped, so the trick is to keep their doors shut. Ready.gov says a closed fridge keeps food cold for about four hours and a full freezer for about two days. Flashlights replace the lights, and a charged power bank can keep a phone going.

Outside, traffic lights and shops might be off too. A day without power might mean board games by the window, reading in daylight and an early night. These are ideas: each place and family is different.

Ready.gov notes that outages can disrupt communications, water and transportation, close stores, gas stations and banks, cause food spoilage and stop medical devices. Its guidance: keep refrigerators and freezers closed (about four hours for a fridge, about 48 for a full freezer), have flashlights for every household member and backup charging, plan for refrigerated medicines and powered medical devices, and go to a community location with power if heat or cold is extreme.

How a particular day would unfold depends on the season, the place and the household; those outcomes are ideas, not predictions.

Electricity travels along wires from far away. If a storm breaks a wire, the electricity cannot get through.

The grid has many paths, like roads. That helps electricity get around a broken one.

The EIA explains that for the grid to stay stable, the amount of electricity being made must match the amount being used. Many organizations work together to keep that balance.

The grid in the lower 48 U.S. states is made of three big connected systems. Linking local grids together gives electricity many paths to travel, so if one line or power plant fails, others can often take over. That helps prevent widespread blackouts. A storm that breaks lines near your home, though, can still cut you off until crews repair them.

EIA: grid stability requires that electricity supplied match electricity demanded, coordinated among the organizations operating different parts of the grid. The Lower 48 grid consists of three interconnections: Eastern, Western, and ERCOT (most of Texas). Interconnection provides multiple paths for power, which EIA says helps prevent widespread blackouts if a line or plant fails.

Fast-responding storage such as batteries helps hold grid frequency within a narrow range on a second-to-second basis. Redundancy cannot protect every street, though: in 2024, EIA reports, hurricane winds and flooding damaged transmission and distribution lines and substations, leading to prolonged outages.

Hospitals cannot let their machines stop. They have big backup generators that switch on when the power goes out.

Generators must always stay outside, away from windows.

Some places cannot be without electricity, even for a minute. U.S. rules for hospitals require emergency and standby power systems, including emergency generators that are regularly inspected and tested, and a plan to keep them fueled during an emergency.

Some homes have batteries, often charged by solar panels, that can provide backup electricity during an outage. Homes that use a portable generator must follow one safety rule above all: Ready.gov says to run it only outdoors, at least 20 feet from windows and doors, because it gives off carbon monoxide, a poisonous gas.

Under 42 CFR 482.15(e), U.S. hospitals participating in Medicare must implement emergency and standby power systems based on their emergency plans, locate and test emergency generators according to the NFPA 99, NFPA 101 and NFPA 110 codes, and, if they keep fuel on site, plan how to keep emergency power running.

EIA notes that energy storage owned by on-grid customers can provide emergency backup during outages; in 2021, U.S. utilities reported 740 MW of residential small-scale battery capacity. Ready.gov's generator guidance: outdoors only, at least 20 feet from windows, doors and attached garages, with battery-backed CO detectors on every level.