Data & methodology

How we count stations, where prices come from, and what we leave out.

Station data

Source: the U.S. Department of Energy's Alternative Fuels Data Center station database, read through its public API for fuel type hydrogen, United States and Canada. Current pull: September 20, 2026, 93 U.S. records.

How we classify a station

  • Public station for cars: access is public, and the record is marked retail or light-duty. These are the stations in our headline counts.
  • Open / unavailable / planned: AFDC status codes E, T and P. “Temporarily unavailable” is AFDC's label; some stations have carried it for more than a year, and we flag those.
  • Truck-only: public heavy-duty sites that are not retail car stations. Listed separately.
  • Call-ahead / non-retail: public in name but requiring an appointment. Listed separately and not counted.
  • Private: fleet, government and research stations. Excluded from every count and station list, and shown only on the outside-California page with a clear label.

A station's “maximum vehicle class” in AFDC describes the largest vehicle that fits, so a retail station marked medium- or heavy-duty still serves cars. A small number of AFDC records are overridden by hand where the database label is known to be misleading; each override is recorded with its reason.

Why other counts differ

The Hydrogen Fuel Cell Partnership's California station list, the California Energy Commission's dashboard and AFDC are updated on different schedules and define “open” differently, so their totals rarely match on a given day. We publish AFDC's numbers because the data is open and nationwide, and we say when the partnership's list disagrees. We do not copy or mirror the partnership's live status data; we link to it.

Freshness

The map reads the live AFDC database. Status pages are rebuilt from a fresh pull at least monthly and show the pull date. Every station row shows the date AFDC last confirmed it, highlighted if older than 12 months. We keep a dated snapshot of each pull so changes over time can be shown.

Prices

There is no public, per-station feed of hydrogen prices. We use the DOE's quarterly Alternative Fuel Price Report for a national average (its hydrogen sample is small) and operators' posted prices, each shown with the date it was observed. Cost-per-mile figures are our arithmetic from stated inputs, which are listed on the calculator page.

Editorial sources

DOE and national laboratory publications; California Energy Commission and Air Resources Board hydrogen assessments; Hydrogen Fuel Cell Partnership station lists and network updates; manufacturer specifications and press releases; SAE J2601 for fueling; and named news reporting for dated events. Guides show a review date and are re-checked at least twice a year, because this market changes quickly.

Corrections and independence

Tell us about errors through the contact page; we fix the page and update its date. Station-level errors are best reported to AFDC so the fix reaches everyone. The U.S. Department of Energy, AFDC, the National Laboratory of the Rockies and the Hydrogen Fuel Cell Partnership do not endorse or sponsor this site.

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