Mariposa Energy Project
Natural gas power plant in Alameda County, California. 199.6 MW of nameplate capacity across 4 generators, operated by Diamond Generating Corporation.
Also known as EIA plant 57483
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 199.6 MWNameplate
- Generators
- 4 operatingEIA-860M, August 2026
- Operating since
- October 2012First generator online
- Operator
- Diamond Generating CorporationEIA operator ID 49981
- Grid
- CAISOBalancing authority CISO
- Price nodes
- 1 CAISO nodeResource nodes with prices
- Location
- Alameda County, CA37.7892, −121.6019
- EIA plant ID
- 57483EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Mariposa Energy Project produces
Free · EIA-923Net generation, 2025
29.1 GWh
29,135 MWh, final
Capacity factor, 2025
1.7%
2024: 5.3%
January to July 2026
22.3 GWh
Provisional
Range, 2015 to 2025
29.1–136.3
GWh a year. Low 2025, high 2017
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | Not reported | Not reported | 0 of 12 |
| 2001 | Not reported | Not reported | 0 of 12 |
| 2002 | Not reported | Not reported | 0 of 12 |
| 2003 | Not reported | Not reported | 0 of 12 |
| 2004 | Not reported | Not reported | 0 of 12 |
| 2005 | Not reported | Not reported | 0 of 12 |
| 2006 | Not reported | Not reported | 0 of 12 |
| 2007 | Not reported | Not reported | 0 of 12 |
| 2008 | Not reported | Not reported | 0 of 12 |
| 2009 | Not reported | Not reported | 0 of 12 |
| 2010 | Not reported | Not reported | 0 of 12 |
| 2011 | Not reported | Not reported | 0 of 12 |
| 2012 | 27,922 | Not reported | 3 of 12 |
| 2013 | 77,900 | 4.5% | 12 of 12 |
| 2014 | 99,673 | 5.7% | 12 of 12 |
| 2015 | 82,931 | 4.7% | 12 of 12 |
| 2016 | 85,575 | 4.9% | 12 of 12 |
| 2017 | 136,297 | 7.8% | 12 of 12 |
| 2018 | 112,210 | 6.4% | 12 of 12 |
| 2019 | 90,836 | 5.2% | 12 of 12 |
| 2020 | 104,297 | 5.9% | 12 of 12 |
| 2021 | 91,265 | 5.2% | 12 of 12 |
| 2022 | 94,567 | 5.4% | 12 of 12 |
| 2023 | 87,728 | 5.0% | 12 of 12 |
| 2024 | 93,437 | 5.3% | 12 of 12 |
| 2025 | 29,135 | 1.7% | 12 of 12 |
| 2026 (provisional, partial year) | 22,274 | 2.2% | 7 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free account · CAISOEmissions
Free · EPA CAMPDCO₂, 2025
17,841
US short tons. 2024: 56,323
SO₂, 2025
0
US short tons
NOx, 2025
2
US short tons
CO₂ per MWh, calculated
0.61 t
About 1,225 lb per MWh
4 of 4 EPA units reported CO₂ in 2025 (GT-1, GT-2, GT-3, GT-4), matched to EIA plant 57483 through the EPA–EIA crosswalk. The per-MWh rate is EPA CO₂ divided by EIA-923 net generation. The two reporting boundaries can differ.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| CTG1 | Natural Gas Fired Combustion Turbine | 49.9 | October 2012 |
| CTG2 | Natural Gas Fired Combustion Turbine | 49.9 | October 2012 |
| CTG3 | Natural Gas Fired Combustion Turbine | 49.9 | October 2012 |
| CTG4 | Natural Gas Fired Combustion Turbine | 49.9 | October 2012 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists Diamond Generating Corporation as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
Generation potential vs reported
Monthly potential at seasonal net capability, next to EIA-923 output. Shows how much of the plant's capability was used.
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Questions about Mariposa Energy Project
How much power does Mariposa Energy Project produce?
Mariposa Energy Project reported 29,135 MWh (29.1 GWh) of net generation in 2025, a 1.7% capacity factor on 199.6 MW of nameplate capacity. From January to July 2026 it reported 22.3 GWh, which is provisional.
Where is Mariposa Energy Project?
Mariposa Energy Project is in Alameda County, California, at 37.7892, −121.6019. It is in the California Independent System Operator balancing area (CISO).
Who operates Mariposa Energy Project?
EIA-860M for August 2026 lists Diamond Generating Corporation as the operator (EIA operator ID 49981). The operator is not always the owner.
When did Mariposa Energy Project start operating?
Its first generator began operating in October 2012, according to EIA-860M.
Does InfraMap have power prices for Mariposa Energy Project?
Yes. InfraMap has CAISO day-ahead and real-time prices at 1 price node linked to Mariposa Energy Project, with the hub price and node-to-hub basis. Prices are free with an InfraMap account; pricing node names are part of InfraMap Pro.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- EPA CAMPD annual emissions through the EPA–EIA crosswalk, 1995 to 2025
- CAISO day-ahead and real-time prices; node and hub assignments as of 2026-10-05
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page