RE Tranquillity
Solar and battery storage project in Fresno County, California. 277.3 MW of nameplate capacity across 3 generators, operated by Southern Power Co.
Also known as Tranquillity Solar Project · EIA plant 59939
This project groups RE Tranquillity (EIA 59939). EIA reports them as separate plants.
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 277.3 MWSolar 205.3 · Battery storage 72.0
- Generators
- 3 operatingEIA-860M, August 2026
- Operating since
- July 2016First generator online
- Operator
- Southern Power CoEIA operator ID 17650
- Grid
- CAISOBalancing authority CISO
- Price nodes
- 2 CAISO nodesResource nodes with prices
- Location
- Fresno County, CA36.5814, −120.4045
- EIA plant ID
- 59939EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power RE Tranquillity produces
Free · EIA-923Net generation, 2025
485 GWh
484,790 MWh, final
Capacity factor, 2025
27.5%
2024: 27.8%
January to July 2026
Not reported
Provisional. 0 of 7 months reported
Range, 2017 to 2025
424.9–501.8
GWh a year. Low 2022, high 2018
| 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 | Not reported | Not reported | 0 of 12 |
| 2013 | Not reported | Not reported | 0 of 12 |
| 2014 | Not reported | Not reported | 0 of 12 |
| 2015 | Not reported | Not reported | 0 of 12 |
| 2016 | 207,829 | 26.3% | 6 of 12 |
| 2017 | 455,431 | 25.3% | 12 of 12 |
| 2018 | 501,819 | 27.9% | 12 of 12 |
| 2019 | 493,365 | 27.4% | 12 of 12 |
| 2020 | 428,108 | 23.7% | 12 of 12 |
| 2021 | 48,190 | Not reported | 2 of 12 |
| 2022 | 424,917 | Not reported | 12 of 12 |
| 2023 | 450,448 | 25.5% | 12 of 12 |
| 2024 | 491,435 | 27.8% | 12 of 12 |
| 2025 | 484,790 | 27.5% | 12 of 12 |
| 2026 (provisional, partial year) | Not reported | Not reported | 0 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 CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| BESS1 | Batteries | 37.0 | November 2021 |
| BESS2 | Batteries | 35.0 | March 2022 |
| TQ | Solar Photovoltaic | 205.3 | July 2016 |
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 Southern Power Co as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
Modeled curtailment
A range, not one number. The lower bound counts hours inside the production tax credit window; the upper bound is the no-credit case.
Expected vs reported generation
Monthly modeled expected output and physical potential next to EIA-923 reported output.
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Power plants near RE Tranquillity
More plants operated by Southern Power Co
Questions about RE Tranquillity
How much power does RE Tranquillity produce?
RE Tranquillity reported 484,790 MWh (485 GWh) of net generation in 2025, a 27.5% capacity factor on 277.3 MW of nameplate capacity.
Where is RE Tranquillity?
RE Tranquillity is in Fresno County, California, at 36.5814, −120.4045. It is in the California Independent System Operator balancing area (CISO).
Who operates RE Tranquillity?
EIA-860M for August 2026 lists Southern Power Co as the operator (EIA operator ID 17650). The operator is not always the owner.
Is RE Tranquillity a solar or a battery storage plant?
Both. Solar capacity totals 205.3 MW and battery storage capacity totals 72 MW.
When did RE Tranquillity start operating?
Its first generator began operating in July 2016, according to EIA-860M.
Does InfraMap have power prices for RE Tranquillity?
Yes. InfraMap has CAISO day-ahead and real-time prices at 2 price nodes linked to RE Tranquillity, 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)
- CAISO day-ahead and real-time prices; node and hub assignments as of 2026-10-05
- Plant names from OpenStreetMap, © OpenStreetMap contributors (ODbL)
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page