Graniterock Quarry

☀ SolarIPP Non-CHP4 MW capacity

1048th largest plant in California · 8228th nationally

Graniterock Quarry is a solar power plant in California with a nameplate capacity of 4.4 MW. It generates roughly 9.1k MWh per year — enough to power about 864 average U.S. homes.

Its capacity factor of 24% reflects intermittent or peaking operation.

PeakingMid-meritBaseload0%40%80%100%24%
Peaking — intermittent or backup
Capacity4 MWnameplate
Annual Generation9.1k MWhEPA eGRID
Capacity Factor24%of theoretical max
Annual CO₂metric tons

Location

Plant NameGraniterock Quarry
OperatorCalcom Energy
CityAromas
CountySan Benito County
StateCalifornia
ZIP95004
Coordinates36.87816, -121.60280

This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.

Natural GasSolarBiomassBattery Storage

Generators (1)

IDTechnologyFuelCapacityStatusOnline
GRWQSolar PhotovoltaicSolar4.4 MWOperating2022

Ownership

OwnerLocationShare
Granite Rock CompanyWatsonville, CA10000.0%

Ownership reported to EIA Form 860. Percentages reflect reported generator-level ownership share, averaged when a plant has multiple generators.

Grid context

NERC RegionWECC
Balancing AuthorityCalifornia Independent System Operator

About Solar plants

Utility-scale solar farms convert sunlight directly into electricity using photovoltaic panels. They produce zero direct emissions and have no fuel cost, but generation is variable — peaking at midday and falling to zero at night. Capacity factors typically run 18–28% in good locations.

Other plants in San Benito County

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