California · EIA-860M + EIA-923
Every power plant
has a life.
A demographic portrait of the California grid—where generators are born, work, age, and retire. Watch a century of machinery turn over, one named plant at a time.
Latest census
—
operating plants
Monthly generator records, joined to plant-level operating histories.
Fleet capacity—
Individual generators—
Zero-carbon + storage—
Data vintage—
01 / The population
California’s generating fleet, by age
Thermal resources extend left. Zero-carbon resources and storage extend right. Each band is five years of age.
Data note
Historical frames are loading.
02 / Vital signs
Which gas plants stopped running—or stopped earning?
Two pressures converge into one transparent screen: how little a plant runs (EIA-923 capacity factor) and how little it earns (spark spread at its nearest CAISO price node). A plant can run rarely yet still be worth keeping; one that neither runs nor clears its fuel cost is the one the market is quietly retiring.
Latest EIA-923—
Selected health record
—
Choose a plant
—
Stress screen—/ 100
CF · 12‑mo—
vs prior yr—
Heat rate—
Annual capacity factor%
Combustion CO₂ · trailing 12 mo
—
Earning · spark spread—
In the money—
Energy margin—$/kW-yr
Spark spread—$/MWh median
Perfect-dispatch energy margin$/kW-yr
—
Descriptive screen, not a retirement probability. Energy margin is a perfect-dispatch upper bound from day-ahead nodal prices—it excludes resource-adequacy, ancillary, and bilateral revenue, start-up and min-load costs, and owner strategy.
Stranded asset watch
Highest market stress
| Plant | MW | CF | $/kW-yr | Stress |
|---|
04 / Field notes
How to read the census
Birth and age
Generator operating month is its birth date. Age is recomputed at every monthly frame. The pyramid aggregates generator nameplate MW into five-year cohorts.
Work and efficiency
EIA-923 natural-gas generation divided by nameplate capacity gives capacity factor—idle months count, and co-located solar or batteries are excluded. Fuel burn over generation gives heat rate. Headline vitals use trailing-12-month windows so partial years compare fairly.
Earning, not just running
Spark spread = day-ahead LMP at the plant's nearest CAISO node − heat rate × California gas price. Hours-in-the-money is how often that clears zero; energy margin sums the positive spread as a perfect-dispatch $/kW-yr. Where prices reach a plant the screen weights low use 30%, this economic pressure 28%, decline 16%, heat rate 12%, and age 14%.
What it leaves out
Nodal prices cover recent years, not a plant's whole life; a plant beyond 60 km of any priced node, or with only a class-typical heat rate, is flagged low-confidence. History before the latest 860M workbook's retired-unit window is not yet restored. No claim is made about contracts or retirement probability.
Sources · U.S. Energy Information Administration EIA-860M, EIA-923, and California gas price to electric-power consumers (series N3045CA3); CAISO OASIS day-ahead nodal LMP. California includes CAISO and non-CAISO balancing areas.
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