THERON ENERGY UNIVERSITY EXPLAINING THE DIFFERENCE BETWEEN kW and kVA:
A kWh is a measure of energy over a span of time and kW is a measure of power. Power is the rate at which something uses energy, and energy is the capacity to do work.
KVA is a measure of power, similar to KW but includes reactive power which is a factor for customers with considerable inductive loads.
{An inductive load converts current into a magnetic field. Inductive reactance resists the change to current, causing the circuit current to lag voltage.}
kVA is a measure of apparent power: it tells you the total amount of power in use in a system. In a 100% efficient system kW = kVA.
However electrical systems are never 100% efficient and therefore not all of the systems apparent power is being used for useful work output. 
kW is the amount of power that is converted into a useful output. kW is therefore known as actual power or working power.
Apparent power (kVA) x power factor (pf) = actual power (kW)
e.g. 100 kVA x 0.8 = 80 kW

Note: 1 kW = 1.341 Mechanical Horsepower