The 51 balancing authorities GridPulse forecasts

51 of 63, and roughly 100% of lower-48 demand

The EIA’s hourly grid dataset covers 63 balancing authorities in the contiguous United States. GridPulse forecasts 51 of them — about 81% by count, but close to 100% by demand, because the ones not covered are small.

Those two percentages describe the same coverage and are worth keeping apart. Counting balancing authorities treats a 150,000 MW interconnection and a single municipal utility as equals; weighting by demand does not. Neither number is wrong, and quoting only the flattering one would be.

Alaska and Hawaii are outside the dataset entirely and are not covered.

The full list

How capacity is derived — and where it is an estimate

Most rows sum the nameplate capacity of every generating unit inside the balancing authority that EIA lists as operating.

Seven rows cannot be built that way, and are marked est. above. For those authorities the in-territory generation runs below the load they actually serve — they import a substantial share of their power — so summing local plates would understate the system badly. Those rows use peak demand × 1.15 instead.

That multiplier is not a reserve margin, and should not be read as one. It is a rough allowance that keeps a utilization figure from exceeding 100% on an import-heavy system. Those authorities are excluded from utilization and top-stress rankings in the product for the same reason.

One authority is deliberately not in that set despite being import-dominated: its capacity is a genuine nameplate figure for a federal dam fleet, so labelling it an estimate would be the inaccuracy rather than the correction.

What is not covered, and why

• Twelve contiguous-US balancing authorities. They are small, and several report demand too sparsely or too erratically to forecast honestly. Adding a region whose feed cannot support a forecast produces a number, not an answer.
• Alaska and Hawaii. Neither is in the EIA hourly grid dataset this is built on.
• Sub-authority geography. Forecasts are per balancing authority, not per utility, city or node. A row covering fourteen states is one forecast, not fourteen.

Coverage grew in three steps — 8 authorities, then 16, then the present 51.

Reading a row

Code is the EIA identifier, and the same string the public API accepts — for example /api/v1/forecast/ERCOT. States served lists where an authority operates, which for the large interconnections is many states and for a municipal utility is one. Capacity is the figure described above.

Accuracy is not on this table on purpose. It is measured per balancing authority and moves with every retrain, so it belongs where it can be kept current rather than copied into a second place. The benchmark publishes it per authority →