Feeder and substation capacity data from electric utilities.

Known limits and corrections

Figures are comparable only within a utility and metric type; some are feeder-derived, and some sources can go months without an update. Con Edison’s source data does not include Manhattan below 96th Street. See data quality for corrections and detail.

The API returns capacity at feeder and substation level as JSON, with the source classification on every record.

The site search and batch screening tools use those readings to screen candidate sites for available power.

Utilities publish different kinds of capacity figure. The table below shows a metric type only where the utility's own documentation supports that granularity; figures are only comparable within a utility and metric type.

Data quality and freshness

Utilities publish capacity data at different levels of detail, from individual transformers to whole feeders. The tools standardise format and units, not meaning, retain the units or relevant context, and assign A/B/C quality rankings. Rhode Island figures are in MVA, not MW. Two substation readings can still carry different tiers; granularity alone doesn't establish data quality.

Some sources go long stretches without an update. Site search flags results when the source data is stale, and batch print reports include the API freshness field. These figures support an initial assessment; capacity available to a particular project, connection requirements, costs, and timing still need to be established with the utility.

History

We keep dated readings, so for some utilities you can see how a figure has changed. History is shallow: at most five dated values for a circuit, and only for some utilities. Some changes reflect utility corrections or method changes rather than real movement, and we record those.

Coverage

Under review means the stored classification has not yet been checked against the utility's own documentation.

Known gap: Con Edison’s source data does not include Manhattan below 96th Street.

Sample result

The map

The map supports searches within a drawn boundary or a radius around an address or dropped pin. Substations in the dataset that fall within the area appear ranked by a weighted score you can adjust (capacity, distance, queue data, equipment loading, data quality). For feeder-derived substations the score leans on distance. A listed substation can show zero or negative capacity; that means no stated headroom.

Individual results can be shared by link or exported as a printable report. Watch a substation to be emailed when its capacity changes (beta).

Batch screening

The batch tool handles an uploaded list of candidate sites in one pass. Each location comes back with ranked nearby substations, using the same weighting options as the map. Results can be downloaded as CSV for use in a spreadsheet or further analysis.

API

The API returns the map's underlying data, including current and historical capacity readings and A/B/C quality tiers. Teams can use the data in their own analysis.

Access

For a first look, try the map with demo key subcapacity, entered in the box at the top right. Demo access allows 2 searches per day. The first request after a quiet period can take up to a minute while the service wakes. Demo access does not include watches or alerts.