Difference between Megawatt and Mega VARs


The megawatt is equal to one million (106) watts. Many events or machines produce or sustain the conversion of energy on this scale. For example: lightning strikes, large electric motors, large warships, such as aircraft carriers, cruisers, and submarines, engineering hardware, and some scientific research equipment, such as supercollider’s, and in the output pulses of very large lasers. A large residential or commercial building may consume several megawatts in electric power and heat.

The productive capacity of electrical generators operated by a utility company is often measured in MW.


Mega VARs:

Mega VAR stands for Mega Volt*Amps Reactive. Although reactive power is not ‘real’ (i.e. it is not considered power at the source or destination), it still consists of current flowing in the transmission lines. When current flows in the line, power (real power) is lost due to I2R losses. When you are talking about Mega VARs, this power loss is significant and is a direct loss for the power company.

This reactive power is usually caused by a company having a large inductive load (lots of motors). If it is bad enough, sometimes companies will put large capacitor banks in or near their factory to try and balance things out. If they don’t, the power company may ask them to pay for the losses.

Here cosθ is known as power factor. It is the ratio of real power to apparent power. It lies between the number 0 and 1.

Kilowatt-hour (KWH):

A kilowatt-hour is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour. Generally it is known as unit.


1 unit electricity = 1 KWH power.

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