The determination of apparent power (kVA) from real power (kW) necessitates consideration of the power factor, a dimensionless number between -1 and 1, representing the efficiency of electrical power utilization. The real power, measured in kilowatts, represents the power actually used to perform work. Apparent power, measured in kilovolt-amperes, is the product of voltage and current in a circuit. For example, if a device consumes 100 kW of real power with a power factor of 0.8, the apparent power would be 125 kVA (100 kW / 0.8 = 125 kVA).
Accurate determination of apparent power is crucial for proper sizing of electrical infrastructure components, including generators, transformers, and wiring. Utilizing excessively small components can lead to overheating, voltage drops, and potential equipment failure. Oversizing components, conversely, results in unnecessary capital expenditure and reduced operational efficiency. Historically, inadequate power factor correction has led to significant energy waste and increased costs for consumers and utilities alike. Improvements in power factor correction technologies have therefore become a significant focus in electrical engineering.