Mousam River Solar
Solar power plant in York County, Maine. 20 MW of nameplate capacity across 1 generator, operated by Walden Renewables Development LLC.
Also known as EIA plant 69499
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 20 MWNameplate
- Generators
- 1 operatingEIA-860M, August 2026
- Operating since
- November 2025First generator online
- Operator
- Walden Renewables Development LLCEIA operator ID 67489
- Grid
- ISO-NEBalancing authority ISNE
- Price nodes
- 1 ISONE nodeResource nodes with prices
- Location
- York County, ME43.4322, −70.7273
- EIA plant ID
- 69499EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Mousam River Solar produces
Free · EIA-923Net generation, 2025
6.88 GWh
6,884 MWh, final
Capacity factor, 2025
Not reported
2024: Not reported
January to July 2026
Not reported
Provisional. 0 of 7 months reported
| 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 | Not reported | Not reported | 0 of 12 |
| 2017 | Not reported | Not reported | 0 of 12 |
| 2018 | Not reported | Not reported | 0 of 12 |
| 2019 | Not reported | Not reported | 0 of 12 |
| 2020 | Not reported | Not reported | 0 of 12 |
| 2021 | Not reported | Not reported | 0 of 12 |
| 2022 | Not reported | Not reported | 0 of 12 |
| 2023 | Not reported | Not reported | 0 of 12 |
| 2024 | Not reported | Not reported | 0 of 12 |
| 2025 | 6,884 | Not reported | 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 · ISONEEmissions
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 |
|---|---|---|---|
| MRS1 | Solar Photovoltaic | 20.0 | November 2025 |
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 Walden Renewables Development LLC 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.
300 analyst questions a month, plus MCP
Query Mousam River Solar and 14,224 other projects from Claude or your own tools. Free accounts get 1 question a day.
Power plants near Mousam River Solar
Questions about Mousam River Solar
How much power does Mousam River Solar produce?
Mousam River Solar reported 6,884 MWh (6.88 GWh) of net generation in 2025.
Where is Mousam River Solar?
Mousam River Solar is in York County, Maine, at 43.4322, −70.7273. It is in the ISO New England Inc. balancing area (ISNE).
Who operates Mousam River Solar?
EIA-860M for August 2026 lists Walden Renewables Development LLC as the operator (EIA operator ID 67489). The operator is not always the owner.
When did Mousam River Solar start operating?
Its first generator began operating in November 2025, according to EIA-860M.
Does InfraMap have power prices for Mousam River Solar?
Yes. InfraMap has ISONE day-ahead and real-time prices at 1 price node linked to Mousam River Solar, 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)
- ISONE 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