Mid-Atlantic (PJM) Electricity Demand Growth, 12-Month vs Prior Year (%)

## What this measures

The percent change in electricity demand over the latest 12 months against the 12 months before, for the Mid-Atlantic region, which is PJM Interconnection: 13 states from New Jersey to Illinois plus D.C., including Northern Virginia's data center cluster. Each point is dated to the last month of its 12-month window.

## Why it matters

It is the cleanest read of whether a grid's load is growing: a full year in each window cancels the seasons, and most of the weather. Regions with large data center build-outs (PJM's Northern Virginia, Texas) show it first, and utilities' capital plans follow it.

## How to read it

Positive means the region used more electricity than a year earlier. Through most of the 2010s U.S. demand grew by less than 1% a year; sustained growth of 2% or more is a structural change. A hot summer or cold winter can add or subtract about a point on its own.

## What it does not say

It does not separate data centers from other load, nor weather from underlying growth. Demand served by the grid falls as rooftop solar grows. A boundary change between balancing authorities shows up as a step.

## How it's built

Sum of the 12 latest months of power.demand.monthly_gwh.mida divided by the sum of the 12 months before, minus one. Only computed when all 24 months are present. Palanor calculation on EIA data.

## Source

U.S. Energy Information Administration, Hourly Electric Grid Monitor (Form EIA-930), six-month bulk files (eia.gov/electricity/gridmonitor). EIA data are U.S. government works in the public domain; EIA asks that it be credited as the source. Refreshed daily by /api/cron/eia-grid-demand-sync.