About GridStrain

For the first time in decades, U.S. electricity demand is climbing fast — and the biggest new driver is the data center. Training and running AI models takes enormous, around-the-clock power, and that load is landing on regional grids that were planned for slower growth. GridStrain tracks how hard each of America's major grids is working, hour by hour, using official government data.

Think of each grid region like a player's baseball card. Instead of batting average and home runs, you get a Grid Stress Index, a Peak Load, and a read on how clean — or fossil-heavy — the power is right now.

How to read the stats

Grid Stress Index

⚾ Batting average

Current demand as a percentage of the highest demand hour in the past 365 days. A reading near 100% means the grid is pushing toward its recent record. Because the EIA doesn't publish a single "maximum capacity" figure per region, we use the rolling one-year peak as the yardstick — so this is a measure of strain relative to how hard the grid has recently had to work.

Peak Load

⚾ Home runs

The single biggest hour of demand over the last seven days, in gigawatts (GW) — the raw scale of power the region is pulling at its busiest.

Clean Generation

⚾ On-base %

The share of electricity being generated right now from wind, solar, hydro, nuclear, and geothermal. A useful check on whether new demand is being met with clean power or not.

Fossil Baseline

⚾ Small ball

The gigawatts coming from coal, natural gas, and oil — the "heavy lifting" fossil generation that fills in when renewables dip.

The regions we track

We follow seven of the largest U.S. balancing authorities — the operators responsible for keeping supply and demand in balance across their territory.

PJM Interconnection — Mid-Atlantic · Data Center Alley. Serves Northern Virginia's Loudoun County, the densest data-center cluster on Earth. The bellwether for AI-driven grid strain.
ERCOT — Texas. Texas runs its own grid. Booming data-center and crypto load meets summer heat and a fast-growing wind + solar fleet.
CAISO — California. The solar-heaviest major grid. Watch the evening ramp when the sun sets and gas fills the gap.
MISO — Midwest. Fifteen states across the nation's industrial midsection, with heavy wind and a large coal + gas baseload.
Southwest Power Pool — Central Plains. The wind belt. On gusty nights renewables can supply the bulk of demand across the central plains.
NYISO — New York. New York State, where downstate demand and upstate hydro + nuclear shape a distinctive fuel mix.
ISO New England — New England. Six states reliant on natural gas, with growing offshore wind and a winter price sensitivity all its own.

Where the data comes from

Every number here traces back to the U.S. Energy Information Administration (EIA) Hourly Electric Grid Monitor, a free, public, federal data source. We pull demand, day-ahead forecast, net generation, and generation-by-fuel for each region and store it so the site stays fast — with continuous hourly history going back to January 2019.

A note on timing:demand updates within about an hour, but some regions — notably PJM — report their fuel mix and net generation several days later. When that happens, a region's fuel-mix donut shows the most recent fully reportedhour, which may lag the live demand reading. The timestamp on each chart tells you exactly which hour you're seeing.

GridStrain is an independent project. It is not affiliated with, or endorsed by, the EIA or the U.S. government. Public-domain data is used under the EIA's open-data terms with attribution.