What is reactive power and in utility bill charges apply in that?
Reactive power is the component of AC power where the currents and voltage waveforms lags or leads each other by 90 degrees producing no real power and thus no real energy. If the power consumed is measured in kilo Volt x Ampere (KVA) then it includes both the real and reactive power combined. If it is measured in KW then it includes only the real power, the type that produces work and heat. Modern power meters can calculate both of these types of power and leave the utility company the option to charge you for either. Depending on the units in your electric bill - KVAh or KWh you can tell if your bill includes the reactive component. In residences the difference between the two is too small to be concerned. With a little math we can show the difference. If the voltage V and current I are complex numbers then the KVA is |VI| while the KW measurement is VI*. Why should the electric company charge for the reactive power if it does nothing? Because the reactive current still consumes real power as it flows through power lines and heats up the copper.