Defined term
Photovoltaic capacity factor
Photovoltaic capacity factor is electrical energy generated over a period divided by the energy that would result from operating at the stated rated capacity throughout that period.
Also known as PV capacity factor
measurement · Concept code GS-CONCEPT-042 · Last verified August 20, 2026
Definition and boundaries
Definition
Photovoltaic capacity factor is electrical energy generated over a period divided by the energy that would result from operating at the stated rated capacity throughout that period.
Definition claim verification: Verified August 20, 2026
In plain language
When comparing Photovoltaic capacity factor, keep the unit, time period, measurement boundary, and underlying assumptions the same on both sides.
What it is not
It is not module efficiency and it does not state when within the period energy was generated.
Decision context
Why it matters
The rating basis, energy boundary, period length, downtime, resource, orientation, and curtailment must be aligned before values are compared.
Decision-context claim verification: Verified August 20, 2026
Information boundary
This page provides general educational context, not a site design, production guarantee, utility determination, contract interpretation, legal opinion, tax conclusion, or individualized financial advice. Verify property, equipment, utility, jurisdiction, program, and agreement details before acting.
Concept relationships
Affects
- Annual solar productionPublished conceptPhotovoltaic capacity factor can affect how Annual solar production is evaluated
Primary sources
- National Laboratory of the Rockies: PVWatts Version 8 API
Revision PVWatts API 8.0 · website 8.5.2 · Source event as of September 25, 2025 · Ontology accessed August 20, 2026 · Ontology verified August 20, 2026
- National Renewable Energy Laboratory: System Advisor Model Help
Revision System Advisor Model 2023.12.17 help · Source event as of December 17, 2023 · Ontology accessed August 20, 2026 · Ontology verified August 20, 2026
What to do next
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