How the US electricity grid works (a simplified version)

The power grid is a network of power plants, wires and control rooms that makes electricity and delivers it the moment you need it. It’s easier to picture as a restaurant, so here are its five main parts, each with a real number.

• 🍳

  Power plants are the kitchens

  Every kitchen cooks the same dish, electricity, from different ingredients: gas, wind, sun, water, coal or uranium.

  In real life

  US utility-scale plants generated about 4.43 trillion kilowatt-hours (kWh), the unit your usage is measured in, in 2025.^⁠[1]

• 🛣️

  Wires are the roads

  Transmission lines are the interstates, and they carry a lot of power a long way. Distribution lines are the local streets that end at your driveway.

  In real life

  The US has thousands of miles of high-voltage lines and millions of miles of low-voltage lines.^⁠[2]

• 🚦

  Grid operators are air traffic control

  They don’t make the power, and they don’t own most of the roads. They watch everything that’s moving and keep it from colliding.

  In real life

  A balancing authority “ensures, in real time, that power system demand and supply are finely balanced.”^⁠[6]

• 🔋

  Batteries are the pantry

  Grid batteries store extra power when there’s plenty of it, like at midday when the sun is strong, and hand it back later.

  In real life

  Developers plan to add 24 gigawatts of utility-scale battery storage in 2026.^⁠[17]

• 💡

  Your home is the dinner table

  This is where everything ends up. The meter by your door counts every bit that’s served.

  In real life

  The average US home used about 899 kWh a month in 2022.^⁠[21]

Most US electricity comes from natural gas, followed by renewables, nuclear and coal. Here’s how the US Energy Information Administration (EIA) splits what utility-scale power plants made in 2025.^⁠[1]

• 41% came from natural gas, the biggest single source.
• 24% came from renewables: wind about 11%, solar about 7%, hydropower about 6% and biomass about 1%.
• 18% came from nuclear plants.
• 17% came from coal.

Petroleum and other sources made less than 1%. These numbers also leave out rooftop panels, which EIA estimates made about 0.09 trillion kWh on top of that total.^⁠[1]

Renewable plants feed the same grid as every other plant. Developers plan a record 86 gigawatts of new capacity for 2026: 51% solar, 28% battery storage and 14% wind.^⁠[17]

Rooftop panels aren’t an option for everyone. The US Department of Energy cites an analysis finding that nearly 50% of households and businesses can’t host rooftop solar, often because they rent. Community solar lets you subscribe to a share of a nearby solar project instead, and your share earns a credit on your regular electric bill.^⁠[18]

Electricity reaches your home over two kinds of wires, transmission and distribution. Each stretch of the trip shows up somewhere on your bill.

Transmission is the long-distance part. It runs at very high voltage, because high voltage moves power long distances more efficiently and cheaply.^⁠[2]

Distribution is the local part, where the voltage comes down until it’s safe to use inside homes.^⁠[2] Your local utility owns and fixes the distribution lines.^⁠[13]

No single company runs the US grid. It’s split into three big regional grids, and inside each one, grid operators, utilities and regulators share the work.

No, the lower 48 states run on three main grids, called interconnections. They operate mostly on their own and trade only limited amounts of power with each other.^⁠[6]

Inside each interconnection, every utility runs in sync at an average of 60 hertz.^⁠[5] That’s why power flows freely within one grid but much less between them. Hawaii is separate, and each of its six main islands has its own grid.^⁠[8]

Seven grid operators serve about two-thirds of the nation’s electricity load. They’re CAISO, ERCOT, ISO New England, MISO, NYISO, PJM and SPP. In much of the Southeast, Southwest and Northwest, utilities run their own systems instead, and they often own the plants and the wires.^⁠[9]

Supply is what you pay for the electricity itself, and delivery is what you pay for the wires that bring it to you. In most of the country, one utility does both: it makes or buys the power, delivers it and bills you.

Utility Co.Jane DoeAccount 12-3456-7890-9

1. 1Supply charges280 kWh @ 9.033¢ / kWh$25.29
2. 2Delivery charges280 kWh @ 12.560¢ / kWh$35.17

Taxes & other charges$4.18

Electricity total$64.64

1. 1The power itself
2. 2The wires to your home

In 13 states and Washington, D.C., there’s statewide residential energy choice, so you can pick the company that supplies your power. In Texas’s competitive areas, choosing is required.^⁠[11] Your local utility still delivers the power, which is why the bill splits into two parts.

In Chicago, supply is about half to two-thirds of a ComEd bill, and delivery is about a third to half. The delivery section always lists ComEd, even if another company supplies your power. The Citizens Utility Board sums it up as “supply + delivery + taxes & fees = amount due.”^⁠[12]

Prices usually change because generation, the biggest part of what electricity costs, gets cheaper or more expensive.^⁠[16]

• Fuel costs: natural gas makes more US power than any other source,^⁠[1] so when its price rises, electricity prices tend to rise too.^⁠[16]
• Peak demand: demand is usually highest in the afternoon and early evening, when the grid has to run more expensive plants. Prices are usually highest in summer.^⁠[16]
• Weather: heat waves and cold snaps push demand up, and droughts or calm winds can cut low-cost hydro and wind power.^⁠[16]
• The wires: building, maintaining and repairing the grid, including after storms, adds cost.^⁠[16] Your utility’s delivery rates change when regulators approve new ones.^⁠[14]

Wholesale prices change minute by minute, but most households pay a rate based on seasonal averages. The average US residential price was 17.30 cents per kWh in 2025.^⁠[16]

Some utilities charge more at peak hours and less off-peak, so people shift their use to cheaper times.^⁠[16] Our guide to getting the most out of your electricity account explains when a time-of-use plan is worth it.

Most outages are local, and your utility fixes them.^⁠[13] A storm brings down a line, a tree hits a pole, or a transformer fails.

In 2024, US homes and businesses averaged 11 hours without power, the most in 10 years. Major events like Hurricanes Beryl, Helene and Milton caused 80% of that time. In a typical year, outages outside major events add up to about two hours.^⁠[19]

1. Check whether it’s only you

   If the neighbors have power, check your breaker panel.

2. Report it to your utility, not your supplier

   The utility owns the wires and does the repairs, even if you buy supply from someone else.^⁠[13,20]

3. Stay away from downed lines

   Keep clear of them, and report them to the utility right away.

Rotating outages are short, controlled outages that a grid operator orders when the whole grid runs short of power.

ERCOT orders them only after asking people to save power and using emergency steps, such as bringing in power from neighboring grids. How long each one lasts depends on the local utility, the event and the weather. Smaller transmission operators aim for about 10 to 30 minutes at a time, and larger ones for 60 minutes or more.^⁠[20]

Your utility keeps the wires up, and Public Grid works on the supply side of your bill. Where there’s energy choice, we compare supply rates and look for a lower one, and we check for community solar near you. We earn money through referrals from our energy partners when we connect you to their programs.