- Clean firm
- Operating
- 10 · 100 · 1,000 MW
Map
- Clean firm
- Operating
Mayfield: location. Basemap: Protomaps, © OpenStreetMap contributors, ODbL.
Mayfield
Power plant · Hydro
Key facts
Power plant · Hydroran 42% of 2025 Operating- Capacity
- Capacity: sourceEIA-860M · Open licenseMW
- Commissioned
- 1963
- Net generation, 2025
- 602,506 MWh
- Grid
- 240 kV to City of Tacoma - (WA) (TPWR)
- Location
- Lewis County, Washington
- Operated by
- City of Tacoma - (WA)SourceEIA-860M Preliminary Monthly Electric Generator Inventory
Operations
- Net generation, 2025
- 602,506
MWh - Fuel burned, 2025
- 2,055,751
MMBtu - Capacity factor, 2025
- 42.5
% - Heat rate, 2025
- Not stated
| Year | Net generation (MWh) | Fuel burned (MMBtu) | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|---|
| 2025 | 602,506 | 2,055,751 | 42.5% | — |
| 2024 | 576,354 | 1,966,520 | 40.5% | — |
| 2023 | 545,006 | 1,859,560 | 38.4% | — |
| 2022 | 769,305 | 2,624,869 | 54.2% | — |
| 2021 | 724,784 | 6,409,989 | 51.1% | — |
| 2020 | 725,576 | 6,361,126 | 51.0% | — |
| 2019 | 448,832 | 3,996,850 | 31.6% | — |
| 2018 | 645,975 | 5,880,956 | 45.5% | — |
| 2017 | 870,878 | 8,023,399 | 61.4% | — |
| 2016 | 784,801 | 7,245,284 | 55.1% | — |
| 2015 | 621,103 | 5,788,060 | 43.8% | — |
| 2014 | 821,794 | 7,815,261 | 57.9% | — |
| 2013 | 714,522 | 6,817,255 | 50.3% | — |
| 2012 | 903,472 | 8,597,439 | 63.5% | — |
| 2011 | 828,501 | 8,049,714 | 58.4% | — |
| 2010 | 695,270 | 6,783,054 | 49.0% | — |
| 2009 | 75,281 | 734,743 | 5.3% | — |
| 2008 | 729,626 | 7,189,732 | 51.3% | — |
| 2007 | 647,229 | 6,397,211 | 45.6% | — |
| 2006 | 749,187 | 7,431,187 | 52.8% | — |
| 2005 | 748,707 | 7,486,321 | 52.8% | — |
| 2004 | 809,530 | 8,113,110 | 56.9% | — |
| 2003 | 646,292 | 6,618,672 | 45.5% | — |
| 2002 | 688,438 | 7,003,480 | 48.5% | — |
| 2001 | 430,095 | 4,444,172 | 30.3% | — |
How these are worked out
Net generation and fuel burned are the monthly figures EIA publishes in its bulk electricity file, from the plant's Form 923 reports; a year is the sum of its months. Capacity factor is a full year's net generation over today's nameplate capacity times the hours in that year (8,784 in a leap year), so a plant uprated or partly retired since reads against its current size; heat rate is fuel burned over net generation, for plants that burn fuel. A year with fewer than twelve months stated has no capacity factor, and a value outside the plausible range is left blank rather than shown. By month, the charts apply the same rules to each month's own hours and fuel.
Sources
3 sourcesSources
- EIA-860M
- GEMGlobal Integrated Power Tracker, Global Energy Monitor, September 2026 release (https://globalenergymonitor.org/projects/global-integrated-power-tracker), CC BY 4.0. Modified by Inframation: TransitionZero-sourced rows removed; statuses and technologies mapped to Inframation's vocabulary; figures aggregated. Copyright © Global Energy Monitor. Global Integrated Power Tracker, September 2026 release. Distributed under a Creative Commons Attribution 4.0 International License.
- EIASource: U.S. Energy Information Administration, Electricity bulk data (Form EIA-923 monthly plant series)