When a U.S. power plant's status changes back, PUDL's EIA-860M changelog misses it

Description and use

PUDL’s monthly changelog drops a status change that reverts to a previous value, causing discrepancies with EIA’s 2026 workbook. The fix is to compare each record only with the previous record of the same generator.

Problem

PUDL’s monthly changelog of EIA‑860M generator records drops a status change that reverts to a previous value, causing discrepancies with EIA’s own 2026 workbooks.

Outcome

The changelog’s omission rule caused 2,395 mismatches in 2026 data; correcting the rule aligns PUDL with EIA’s workbook for all affected generator‑months.

Workflow

• 1. Identify the rule that drops a record if an earlier record with identical values exists.
• 2. Observe that a status change that reverts to a previous value is omitted.
• 3. Pre‑register a test to compare the rule’s output with EIA’s 2026 workbook.
• 4. Run the simulation for January–August 2026 and confirm 2,395 disagreements are resolved.
• 5. Modify the rule to compare each record only with the previous record of the same generator.
• 6. Re‑run the simulation to verify all disagreements are eliminated.
• 7. Recommend checking PUDL data against EIA’s workbook for the current month until the fix is deployed.

Evidence

All checks passed and all four of my predictions held: The published changelog has no two records of a generator that are equal in every column but the dates (0 of 224,408 rows), which is what the rule implies.

Source

In 2,395 of 299,999 generator-months (January to August 2026) EIA's workbook and the changelog disagree on status, planned month or capacity. A simulation of the rule gives the changelog's value in all 2,395.

Source

The fix is small: compare each record with the previous record of the same generator rather than with its whole history.

Source