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Earth Energy Log

Capacity factor

In one line

Ratio of actual energy generated over a period to the maximum possible at nameplate capacity, expressed as a percentage.

What it means

Capacity factor is the fraction of nameplate capacity a generator actually delivers over a period. Onshore wind 2026 global average: 35–45%; offshore wind: 45–55% (better wind resource). Utility solar PV: 18–28% (no nighttime). Combined-cycle gas: 50–60%. Nuclear: 90%+. Capacity factor is the single most useful number for comparing intermittent vs. dispatchable generation economics.

Related terms

Browse every term in the renewable energy glossary, or read the latest analysis on Wind.