Ask the Grid

What power grid am I on?

The US doesn’t have one grid — it has three interconnections, seven organized markets, and dozens of utility-run balancing areas, drawn along utility territories rather than state lines. Pick your state for the specific answer, then open that grid live.

Every state, and the grid that runs it

  • Alabama

    Alabama has no organized wholesale market — Alabama Power (Southern Company) serves most of the state, with TVA in the north.

  • Alaska

    Alaska is not connected to the Lower 48 at all — the Railbelt utilities run their own isolated grid between Fairbanks, Anchorage, and the Kenai Peninsula, and remote communities run standalone systems.

  • Arizona

    Arizona has no organized wholesale market — APS, SRP, and TEP balance their own areas within the Western Interconnection.

  • Arkansas

    Arkansas is split: most of the state, including Entergy Arkansas territory, is in MISO, while the western edge is in SPP.

    MISO liveSPP live

  • California

    Most of California is CAISO — but Los Angeles (LADWP), Sacramento (SMUD/BANC), and the Imperial Irrigation District balance their own areas outside it.

    CAISO live

  • Colorado

    Colorado has no organized wholesale market of its own — Xcel Energy and other utilities balance the state within the Western Interconnection, and some eastern-plains cooperatives take service through SPP.

    SPP live

  • Connecticut

    Connecticut is entirely within ISO New England.

    ISO-NE live

  • Delaware

    Delaware is entirely within PJM.

    PJM live

  • District of Columbia

    Washington, DC is entirely within PJM.

    PJM live

  • Florida

    Florida has no organized wholesale market — FPL, Duke Energy Florida, Tampa Electric, and municipal utilities balance their own areas, with a sliver of Southern Company territory in the western Panhandle.

  • Georgia

    Georgia has no organized wholesale market — Georgia Power (Southern Company) and the state's cooperatives and municipals serve it, with TVA touching the northern edge.

  • Hawaii

    Hawaii's islands each run isolated grids operated by Hawaiian Electric and KIUC — there is no interconnection between islands or to the mainland.

  • Idaho

    Idaho has no organized wholesale market — Idaho Power, Avista, and PacifiCorp balance the state within the Western Interconnection.

  • Illinois

    Illinois is split down the middle: northern Illinois (ComEd, including Chicago) is in PJM, and central and southern Illinois (Ameren) is in MISO.

    PJM liveMISO live

  • Indiana

    Indiana is mostly MISO, but the territories of AEP's Indiana Michigan Power and parts of Duke's system sit in PJM.

    MISO livePJM live

  • Iowa

    Iowa is mostly MISO, with western edges served through SPP.

    MISO liveSPP live

  • Kansas

    Kansas is entirely within SPP.

    SPP live

  • Kentucky

    Kentucky is a patchwork: East Kentucky Power and Kentucky Power are in PJM, TVA serves the west, and LG&E/KU run their own balancing area in between.

    PJM live

  • Louisiana

    Louisiana is almost entirely MISO (including all of Entergy's territory), with a small northwest corner in SPP.

    MISO liveSPP live

  • Maine

    Maine is within ISO New England — except far-northern Aroostook County, which connects through New Brunswick rather than the ISO-NE grid.

    ISO-NE live

  • Maryland

    Maryland is entirely within PJM.

    PJM live

  • Massachusetts

    Massachusetts is entirely within ISO New England.

    ISO-NE live

  • Michigan

    Michigan is almost entirely MISO — both peninsulas — with a small southwest corner in PJM through AEP's Indiana Michigan Power.

    MISO livePJM live

  • Minnesota

    Minnesota is entirely within MISO.

    MISO live

  • Mississippi

    Mississippi is split three ways: Entergy Mississippi territory is in MISO, TVA serves the north, and Mississippi Power (Southern Company) serves the southeast.

    MISO live

  • Missouri

    Missouri is split: Ameren territory in the east is MISO, and Evergy territory in the west is SPP.

    MISO liveSPP live

  • Montana

    Most of Montana is utility-balanced within the Western Interconnection (NorthWestern Energy); the eastern edge sits in the Eastern Interconnection with parts served through MISO and SPP.

    MISO liveSPP live

  • Nebraska

    Nebraska is entirely within SPP — served by public power districts (NPPD, OPPD, LES).

    SPP live

  • Nevada

    Nevada has no organized wholesale market — NV Energy balances the state within the Western Interconnection.

  • New Hampshire

    New Hampshire is entirely within ISO New England.

    ISO-NE live

  • New Jersey

    New Jersey is entirely within PJM.

    PJM live

  • New Mexico

    Most of New Mexico is utility-balanced within the Western Interconnection (PNM, El Paso Electric); the southeastern corner, served by Xcel's SPS, is in SPP.

    SPP live

  • New York

    New York is entirely within NYISO — one state, one ISO, eleven load zones.

    NYISO live

  • North Carolina

    North Carolina has no organized market for most of its territory — Duke Energy balances the bulk of the state — but the northeastern counties served by Dominion are in PJM.

    PJM live

  • North Dakota

    North Dakota is split between MISO in the east and SPP in the west.

    MISO liveSPP live

  • Ohio

    Ohio is entirely within PJM.

    PJM live

  • Oklahoma

    Oklahoma is entirely within SPP.

    SPP live

  • Oregon

    Oregon has no organized wholesale market — BPA, PacifiCorp, and Portland General balance the state within the Western Interconnection.

  • Pennsylvania

    Pennsylvania is entirely within PJM — the market's original home.

    PJM live

  • Rhode Island

    Rhode Island is entirely within ISO New England.

    ISO-NE live

  • South Carolina

    South Carolina has no organized wholesale market — Duke Energy, Dominion Energy South Carolina, and Santee Cooper balance the state.

  • South Dakota

    South Dakota is split between SPP in the west and MISO in the east.

    SPP liveMISO live

  • Tennessee

    Tennessee has no organized wholesale market — TVA balances virtually the entire state.

  • Texas

    About 90% of Texas load is on ERCOT — its own interconnection, separate from the rest of the country. El Paso is in the Western Interconnection, and the upper Panhandle plus parts of east Texas are served through SPP and MISO.

    ERCOT liveSPP liveMISO live

  • Utah

    Utah has no organized wholesale market — PacifiCorp (Rocky Mountain Power) balances the state within the Western Interconnection.

  • Vermont

    Vermont is entirely within ISO New England.

    ISO-NE live

  • Virginia

    Virginia is almost entirely within PJM — including the data-center corridor in the north; a small southwestern corner is served by TVA.

    PJM live

  • Washington

    Washington has no organized wholesale market — BPA and the state's utilities balance it within the Western Interconnection.

  • West Virginia

    West Virginia is entirely within PJM.

    PJM live

  • Wisconsin

    Wisconsin is almost entirely MISO, with a small northwestern area historically tied to the MISO market through Xcel's system.

    MISO live

  • Wyoming

    Wyoming has no organized wholesale market — PacifiCorp and Black Hills balance the state within the Western Interconnection.

Common questions

What power grid am I on?
It depends on your state — and sometimes on your county. Seven organized markets (ERCOT, PJM, MISO, CAISO, NYISO, ISO-NE, and SPP) operate the grid for about two-thirds of US demand; the Southeast and most of the non-California West are run directly by utilities instead. Pick your state above for the specific answer.
What are the three US power grids?
The continental US runs on three nearly independent interconnections: the Eastern Interconnection, the Western Interconnection, and ERCOT (most of Texas). They operate at the same frequency but are only weakly linked by a handful of DC ties, so power mostly cannot flow between them.
What is the difference between an ISO and a utility?
An ISO (independent system operator) runs a wholesale market and dispatches the grid across many utilities' territories; your utility still owns the wires and sends your bill. In regions without an ISO, the utility does both jobs — it balances its own area and there is no organized market.
Why does my state have more than one grid operator?
Grid boundaries follow utility service territories, not state lines. States like Illinois, Missouri, and the Dakotas are split between two markets because different utilities in the state joined different ISOs.

Want the deeper mechanics? Read balancing authority in the glossary, or explore all seven markets on the markets directory.