A Kilowatt (kW) is a unit of power equal to 1,000 watts (W). It measures the rate at which energy is consumed or produced. In electrical systems, kilowatts are commonly used to express the power output of generators, the energy consumption of appliances, and industrial electrical loads. For example, a 2 kW heater consumes 2 kilowatts of power per hour when running. In electricity billing, energy usage is measured in kilowatt-hours (kWh), representing the total energy consumed over time.

Kilovolt-Ampere (kVA) is a unit of apparent power in an electrical system, representing the total power supplied, including both active (real) and reactive power. It is commonly used for rating transformers, generators, and UPS systems. The relationship between kVA and kilowatts (kW) depends on the power factor (PF) of the system: 𝑘𝑊 = 𝑘𝑉𝐴 × 𝑃 𝐹 In purely resistive loads, kVA equals kW, but in inductive or capacitive systems, kVA is higher due to reactive power.

Kilovolt-Ampere Reactive (kVAR) is the unit of reactive power in an AC electrical system. Reactive power does not perform useful work but is necessary to maintain voltage stability and support inductive loads like motors, transformers, and fluorescent lighting. It is a component of apparent power (kVA), alongside real power (kW), and is influenced by the power factor (PF) of a system. Managing kVAR effectively through power factor correction (e.g., capacitor banks) helps improve system efficiency and reduce electricity costs.