Capacity Factor

Capacity factor is the ratio of the electricity a power plant actually generates over a period to what it would generate if it ran at full rated output the entire time, expressed as a percentage. It matters directly to data centers signing power purchase agreements (PPAs) for renewable generation: utility-scale solar typically runs a 20-30% capacity factor, onshore wind 30-45%, offshore wind up to 50-55%, while nuclear and combined-cycle gas plants often exceed 85-90%. Because data centers need continuous, 24/7 power but wind and solar generate intermittently, a low capacity factor forces operators either to overbuild renewable capacity relative to their load, pair it with battery storage or firm generation, or accept lower "additionality" claims in their sustainability reporting. Capacity factor is one of the key numbers behind the industry's push toward 24/7 carbon-free energy matching, load-following PPA structures and behind-the-meter generation for AI-scale campuses.