ISO-NE's Seven Day Capacity Forecast — forecast peak load against available capacity for each of the next seven days, with the operator's own surplus figure and any watch or warning it has declared.
Does New England have enough power this week?
ISO-NE forecast demand peaks at 18,600 MW on Fri, 12 AM, against a low of 15,760 MW — a swing of 2,840 MW across the window. Forecast peak demand is the heaviest area at 18,600 MW.
Plotted window Aug 28, 12:00 AM EDT → Sep 2, 12:00 AM EDT. Reissued daily by ISO-NE; the latest published vintage is shown.
Every line above, and who produced it.
The grid operator's own published forecast for these hours. Source: ISO New England.
Generating capacity expected to be available to serve demand.
Each day of the window on its own.
Every hour of the window, shaded by load.
| Series | Peak (MW) | Peak hour | Low (MW) | Average (MW) |
|---|---|---|---|---|
| Forecast peak demand | 18,600 | Fri, 12 AM | 15,760 | 17,435 |
| Forecast available capacity | 29,873 | Fri, 12 AM | 28,608 | 29,253 |
| Capacity on outage | 2,994 | Wed, 12 AM | 1,485 | 2,430 |
| Forecast | Produced by | Method | Horizon |
|---|---|---|---|
| Forecast peak demand | ISO New England | ISO-NE Seven Day Capacity Forecast | 7 days ahead, one assessment per market day |
| Forecast available capacity | ISO New England | ISO-NE Seven Day Capacity Forecast | 7 days ahead, one assessment per market day |
ISO-NE publishes a point assessment with no confidence interval, and a forecast peak seven days out moves substantially with the weather. The surplus figure is only as good as the outage picture on the day it was issued, and forced outages arrive without notice.
Each day, ISO New England publishes an adequacy assessment for the coming week: the peak demand it forecasts, the generation and imports it expects to be available, the capacity out on outage, and the operating reserve it is required to hold above the peak. The surplus or deficiency it states is the difference between them — and a negative number is the finding this feed exists to publish.
Adequacy is assessed against the worst hour of a day, so ISO-NE states one peak-load number and one available-capacity number per market day rather than a curve. That is the publication, not a summary we computed: there is no hourly version of this feed, and spreading a daily peak across twenty-four hours would invent twenty-three numbers ISO-NE never issued.
New England has no in-region gas production and limited pipeline capacity into it. On the coldest days, gas that would otherwise generate power is committed to heating, and the region leans on imports, oil, and its remaining dual-fuel units. This forecast is where that arithmetic becomes visible a week before it is tested.
PowerWatch and PowerWarn are ISO-NE's own escalating declarations that reserves are expected to be short. When one is set for a day it appears here verbatim, unchanged and untranslated. No day without one is labelled reassuringly — the absence of an alert is shown as an absence.
curl "https://askthegrid.com/api/v1/grid/radar/curves?iso=ISONE&horizon=extended"
Connect your agent to mcp.askthegrid.com and this forecast is a tool call away — the same host Claude and ChatGPT connectors already use.
It is ISO New England's daily adequacy assessment for the coming week: forecast peak demand, expected available capacity including imports, capacity on outage, the required operating reserve, and the surplus or deficiency between them.
Because that is how ISO-NE publishes it. Adequacy is judged against a day's worst hour, so the operator states a single peak-load and a single available-capacity figure for each market day. Rendering it as an hourly curve would mean inventing values.
They are ISO-NE's own declarations that operating reserves are expected to fall short, escalating from watch to warning. When one is issued for a day in the window, this page shows it as ISO-NE labelled it.