MAYFIELD

How MAYFIELD compares

With 162 MW of capacity, MAYFIELD ranks 39th among the 126 operating power plants Bywatts maps in Washington and 18th of the 65 operating Hydro plants in the state. It accounts for about 0.8% of Washington's operating Hydro capacity and 0.5% of all operating capacity in the state. Nationally it is the 110th-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1963, it is older than 68% of the 125 operating Washington plants with a recorded commissioning year. Its operator, CITY OF TACOMA - (WA), runs 7 operating plants in Washington totaling 713 MW. It shares Lewis County with 5 other operating plants, including TRANSALTA CENTRALIA GENERATION and CHEHALIS GENERATING FACILITY.

EIA-860 lists 4 generators at the site with 162 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 576 GWh in 2024 (a 41% capacity factor), down 25% from 2022. Its generators came online between 1963 and 1983.

Grid neighborhood

The nearest named substation is MAYFIELD (230 kV), about 0.2 miles away; the closest transmission line found within 10 miles is a 240 kV line owned by CITY OF TACOMA - (WA), under 0.1 miles away. Another 6 operating power plants totaling 1,744 MW sit within 25 miles; the largest is TRANSALTA CENTRALIA GENERATION (730 MW, Coal).

Computed by Bywatts from HIFLD power plant, substation and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology