Electrical power

Michael Faraday, a British physicist, uncovered the underlying principles of several types of electricity generation in the 1820s and early 1830s. The movement of a loop of wire or a disc of copper between the poles of a magnet generates an electric current, which is still utilized today.

It is the first step in the distribution of power to customers for electric companies. The electric power industry is typically responsible for other operations, such as electricity transmission, distribution, and electrical energy storage and recovery via pumped-storage technologies.

The formula of Electrical Power

Electric power is a physics term that refers to the rate at which electrical energy is transferred by an electric circuit per unit of time. The watt, or one joule per second, is denoted by P and measured using the SI unit of power. Electricity is frequently provided by electric batteries and generated by electric generators.

When electric charges flow via a voltage difference (voltage), which occurs in electrical components in electric circuits, they are converted to different kinds of energy.

There are different forms of electric power but the most basic relation of electric power is given as:

P = VI

Where, 

V = voltage of circuit

I = current flowing through the circuit

P = power of the circuit

There are two more relations that are derived from Ohm’s law which defines the relationship between voltage, current, and resistance. 

According to Ohm’s law, 

                                                                        V = IR

Where, 

V = voltage of the circuit

I = current flowing through circuit and

R = resistance of the circuit which is the proportionality constant

Now, the other two forms of electric power are:

                                                                   P = I2 R

And, 

                                                             P = V2 /R

Another expression for electric power is called the instantaneous power, represented as:

                                                                      P = V(t) I(t)

Types of electric power

There are four types of electric power which are classified as:

1. Apparent power: It is defined as the product of the voltage and the current and it is also defined as the total power flowing in the circuit. It is expressed as:

                                                       P = VI

1. Active power: The “active power” is the amount of power that is absorbed and utilized by the load, and it is always less than or equal to the apparent power. It is also known as real power. It is expressed as:

                                                        P = VI cosθ 

Where,

cosθ = power factor which defines the phase angle between the input voltage and current.

We can also define active power as:

                                      Active power = (apparent power) * (power factor)

1. Reactive power: The electricity consumed in an AC circuit that does not conduct any productive work but has a significant effect on the phase angle between the voltage and current waveforms is known as reactive power (Q).

                                                          P = VI sinθ 

1. Complex power: Complex power is defined in the form of a complex number where the real part is presented as the real or active power (P) and the imaginary part is defined as the reactive power (Q). Complex power is denoted by (S). It is expressed as:

                                                   S = P + j Q

The formula in terms of Energy

Energy may be estimated directly using the power because power is the amount of energy consumed per unit of time. It is expressed as: 

                                                                P = E/t

or, 

                                                              P = VQ / t 

where, 

                                                               E = VQ

Here, 

E = energy of the circuit (Joules)

V = potential difference (Volts)

Q = charge (Coulomb)

t = time taken (seconds)

The SI unit of power is in ‘watt’ or ‘joules per second’. Electric power is the scalar quantity.

Conclusion 

Remember that power is the rate at which work is completed – or energy is spent or created – and that it is measured in watts (W). Electric generators are the most common source of electricity, but other sources such as electric batteries can also be used. The electric power sector often provides it to industries and houses (as domestic mains electricity) via an electric power grid.

Transmission lines can carry electric power across vast distances and be used for high-efficiency applications including motion, light, and heat. In hot regions, electric power is utilized to provide air conditioning, and in some areas, electric power is a cost-effective source of power for building space heating. Individual domestic wells to irrigation operations and power storage projects all require electric power to pump water.