Central (SPP) 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 Central region, almost all of it the Southwest Power Pool (SPP) from the Dakotas to Oklahoma. 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.cent 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.