The formula
Capacity factor equals the energy produced divided by the energy the plant would make if it ran at full output the whole time.
Example: a 100 MW plant running flat out for a year of 8,760 hours would make 876,000 MWh. If it makes 219,000 MWh, its capacity factor is 25 percent.
Why it differs by technology
Solar only produces in daylight and wind depends on the weather, so their capacity factors are set mostly by the resource at the site. Gas plants can run whenever fuel is available, so their capacity factor depends on how often they are called on. A low capacity factor is not a fault. It describes how the plant is used.
Questions people ask
Is capacity factor the same as efficiency?
No. Efficiency is how much of the fuel or sunlight becomes electricity. Capacity factor is how much of the time, on average, the plant runs at full output.
Does capacity factor apply to data centers?
The matching idea for a load is load factor: average demand divided by peak demand. Data centers tend to run at a steady level, but check the design of each project.
Related
More glossary
- What is time to power?
- What is powered land?
- What is a powered shell?
- What is large load interconnection?
- What is a point of interconnection?
- What is an interconnection queue?
- What is queue position?
- What is ERCOT?
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