Middle Fork

Hydro power plant in California, United States of America. Approximate location 39.0248, -120.5964.

HydroCaliforniaUnited States of America

Middle Fork is a 122 MW hydro power station in California, United States of America. It is operated by Placer County Water Agency. Based on reported annual generation of 789 GWh, it can supply roughly 225,400 homes. It ranks #1713 of 9,833 United States of America power plants by installed capacity. Commissioned in 1966, it is around 60 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

122MW installed capacity
789GWh reported / yr
225,400homes powered
1966commissioned (~60 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0000425.

Reported generation trend

2013: 327 GWh20132014: 270 GWh20142015: 160 GWh20152016: 532 GWh20162017: 860 GWh20172018: 452 GWh20182019: 789 GWh2019860 GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Placer County Water Agency. All plants by this company →

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 39.0°N — which shapes how much energy it can produce and how its output varies through the year.

11.1°Cannual mean temp
2,650heating degree-days (base 18°C)
132cooling degree-days (base 18°C)
1,299 melevation

Monthly mean temperature

J: 4 °CJF: 5 °CFM: 6 °CMA: 8 °CAM: 12 °CMJ: 16 °CJJ: 20 °CJA: 20 °CAS: 18 °CSO: 13 °CON: 7 °CND: 4 °CD20 °C

Heating degree-days here run 8% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 53/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

How it compares & nearby plants

The #153 largest hydro power plant of 1449 in United States of America by capacity.

United States of America has 1449 hydro power plants in this dataset, together about 101,657 MW of capacity.

Nearby power plants

Location

Coordinates 39.0248, -120.5964 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

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