Electrical Energy (Explained For Beginners)

We define electrical energy as the ability of an electrical circuit to do work. When we supply a voltage source across a conductor, current flows in a conductor for a specific time. As a result electricity is produces.

In other words, we also define Electrical Energy, the work done by the motion of electrons.

Electrical Energy Production And Generation

Electricity is generated by AC generators. These generators have large variation of power levels from small portable generators to large power plants.

All these AC generators are working with the same principle. When a conductor cuts alternating magnetic filed with relative motion this produces electricity in the conductor.

The difference between one generator and the other is the mechanical prime mover which rotates the winding.

Some kind of generators use diesel engines, wind energy, steam engine, and even sea waves energy is used to produce clean and environmental friendly energy.

After generation in large power plants voltage is stepped up using electrical transformers, which is called step-up transformers. This is to transport power using power lines and to reduce losses.

For more information about AC Generator, Read my detailed article here.

Applications Of Electrical Energy

The applications of electrical energy is worldwide and countless. There are other sources of energy like geothermal energy, solar energy, wind energy, biomass, and hydro-power energy, etc. But electricity is the most widely used.

As per 2018 reports, the total amount of electrical energy used in the world was 22,315 TWH. This is because, electricity can be converted into lighting , rotation, heat and more shapes of energy.

So, the main uses of electricity are lighting, cooling, heating, operation motors, computers, communication system appliances, and other machinery related operation.

Electricity uses and examples are around us every where. In our homes, factories, schools, even cars are being converted to work on electricity.

For more about electrical energy uses, read my other article here.

 Electrical Energy Formula

Let’s consider the potential difference between two points A and B. As we know, if one Coulomb charge moves from point A to point B during time “t”. The work done will be one joule. And we can write the work done = v * (q /t)

We can write the electrical power in differential form as;

p = v * (dq /dt)

If we place a conductor between these two points while the charge q passing through the conductor, it is nothing but current. There we know that

i = (dq / dt)

Therefore, we replace the I in the power equation and we get the formula.

p = v * i

Now if the current flows in a conductor for time “t” we can say the work done by the electrical charge as

e = v * i * t

where “e” is the Electrical energy

“v” is the voltage applied (potential difference) to the circuit

“i” is the value of current in amperes

“t” is the time in seconds

For more details about 3 phase power formula read my article here.

Unit of Electrical Energy

The unit of electrical energy is Joule. One joule is the multiplication of one watt and one second. Different units are in use. For example Watt-hours, Kilo Watt-hours, and Megawatt Hours.

Simply electrical energy = electrical power*time

Definition Of Watt Hour: If we use one-watt power for one hour, the amount of energy consumed will be One-watt hour.

Electrical energy converts to lighting
Electrical energy converts to lighting

Cons of Electrical energy

We discussed the different applications of electricity, Without Electricity the smooth process of the world would not be possible.

But everything has its pros and Cons, it’s costly, its generation has effects on the environment, and is very dangerous.

Can Electrical Energy Be Converted To Chemical Energy?

In spite of the fact that there is no direct way for converting electrical energy into chemical energy, it is nevertheless possible to do so by way of a number of other processes in between.

In the process known as the electrochemical reaction, electrical energy is converted into chemical energy when electricity is utilized as a catalyst in a chemical reaction because, electricity is a good conductor of energy.

In the electrolytic cell, chemical energy is produced by transforming electrical energy into chemical energy through the electrolysis of an electrolyte.

Electrolysis is a typical example of how they could interact with one another out of the numerous possible ways in which they could do so.

This process takes place in the electrolytic cell. Electrolysis, on the other hand, can be utilized in conjunction with a catalyst to break down chemical bonds that are present in a solution.

It is possible for energy to be transferred from its electrical form to its chemical form. Electrolysis is one of the most common and significant ways in which they interact with one another.

How Is Electrical Energy Converted In To Mechanical?

The vast majority of devices that are capable of transforming electrical energy into mechanical energy have an electric motor built into them.

 These electric motors get their power from the interaction of the magnetic field of the motor with an electric current.

This reaction creates a torque, which in turn causes the shaft to rotate, which results in the release of mechanical energy.

 An electric motor is a part of many machines and gadgets that helps convert electrical energy into mechanical energy.

In Case Of Ac Motor

An electromagnetic induction phenomenon is used by AC motors to transform alternating current into mechanical power. An AC motor’s basic operation is based on the magnetism principle.

The coil of wire transforms into an electromagnet when an alternating current (AC) charge is applied to it. A magnetic field is created by this electromagnet.

A solid metal axle, a wire loop, a coil, a metal-bar squirrel cage, and other freely revolving electrically conducting metal components are all found inside the stator. The stator outside coils get electricity when an AC motor is running.

A magnetic field that revolves around the outside of the motor is created by the coils being energized in pairs and sequentially.

In Case Of DC Motor

DC motor is made up of the following components: the stator (magnet), the rotor (an axle with a coil attached on it that spins rapidly and functions as an electromagnet), the commutator or key, the power supply (DC), and brushes.

A magnetic field is produced whenever electric current passes through the coil (on the rotor), as we are all aware that magnetic fields are produced by current carrying electric fields.

As a result of this generated magnetic field’s interactions with the stator’s magnetic field, torque is produced. The rotor spins as a result of the torque, producing mechanical energy.

What Shapes Of Energy Can Be Converted To Electrical Energy?

Because electrical energy is a form of energy, it is practically conceivable to transform other forms of energy, such as mechanical energy, heat energy, and chemical energy, into electrical energy.

Following are the shapes of energies that can be converted into electrical energy:

  • Chemical energy.
  • Heat energy.
  • Mechanical energy.
  • Gravitational potential energy.
  • Solar energy.

Let’s See how can differently forms of energy can be converted into electrical energy:

Chemical Energy To Electrical Energy

Let’s take an example of the battery where chemical energy is converts into electrical energy. An electrochemical cell is a device that can transform chemical energy into electrical power.

For this purpose, the electrochemical oxidation-reduction process or reaction is utilized. As such, it is an essential part of the energy conversion process.

Through an electric circuit, electrons can be moved from one substance to another. The actual electrochemical unit for energy conversion, however, is a cell. The chemical reaction used to create electricity is a precise and reliable process.

Electrons in the external circuit are responsible for transmitting electrical energy across a wire while chemical reactions are taking place in the interior circuit.

Heat Energy To Electrical Energy

Since there are no moving components and the system is both straightforward and durable, it is utilized chiefly for space missions, which use radioactive plutonium to generate heat. However, this approach is fundamentally inefficient.

In most power plants, the heat energy created by burning fuel, concentrating sunlight, or nuclear fission is first converted into mechanical energy.

We accomplish this by heating water, boiling it into water vapor, and then passing this highly pressurized water vapor through a turbine. Electromagnetic induction is then used to convert the mechanical energy of rotating turbines into electrical energy.

The conversion of thermal energy into boiling water and using the vapor to turn the turbine is the bottleneck in the latter, which is exceptionally efficient.

The temperature difference between heated water vapor and the surrounding air is what determines how efficient thermodynamic engines are, but there are additional losses as well as some water vapor that naturally escapes.

Overall, that is still the most effective method for converting heat to electricity on a wide scale.

Mechanical To Electrical Energy

The concept of electromagnetism’s Faraday laws is used to transform mechanical energy into electrical energy.

 As a result, whenever a coil is moved in a uniform magnetic field, a current is induced in that coil to cancel out the flux that is induced in that coil. And the device that operates on this concept is referred to as an electric generator.

The rotational mechanical energy created by rotating the turbine’s fins/blades is another type of mechanical energy that can be converted to electrical energy.

By the way, most energy in the world comes from this fundamental principle of pushing the rotor in order to convert it to electrical energy, in which the fins/blades are rotated utilizing a variety of approaches.

The term “generator” is misleading because no energy is produced; instead, only one form of energy is transformed into another. If given electrical power, the same thing can be utilized as a motor to transform electrical energy into mechanical energy.

The alternator is another name for the generator.

Gravitational Potential To Electrical Energy

One form of energy that occurs naturally and spontaneously is the transformation of gravitational potential energy into electrical energy.

Because of the existence of gravity, potential energy is converted into kinetic energy.

Hydroelectric Dams are example of the conversion of gravitational potential energy to electrical energy. They work by capturing and storing the water behind the dam. The water’s gravitational potential energy helps it flow and impact the turbine’s shafts.

Water will be held back at the dam’s end and released as needed to help the turbine spin. When the turbines revolve at a steady speed, power is produced instantly.

This is the process through which hydroelectric dams transform the gravitational potential energy of water into usable electricity.

Is there heat loss when electric energy is transferred to another shape?

Yes, when electric energy is transferred to another shape a portion of electrical energy is dissipated as heat due to various causes such as resistance, mechanical friction, radiation, leakages, etc.

The conversion from one form of energy to another always results in some form of loss in all real-world contexts.

Heat Loss Due To Resistance

A resistor is a component in an electric circuit that acts to reduce the flow of current. Resistors serve a crucial function in shielding circuits from damage caused by overdrawing current by converting the kinetic energy of electrons in current into heat (heat).

The usefulness of electricity comes from the electrons’ ability to transfer their kinetic energy from the voltage source to the devices we want to power, such as toasters and computers.

Heat Loss Due To Mechanical Friction

When electrical energy is converted into mechanical energy, the resultant loss of energy is always experienced in the form of heat.

As a result of this heat energy, the surfaces of contact that were subjected to friction became heated. Alternately, the heat energy might be lost through the circulation of a fluid that comes into touch with the friction-induced contact surfaces.

When this occurs, the fluid that removes the heat energy is also referred to as a coolant because of its function.

Heat Loss Due To Radiation

When electromagnetic fields are created from electric energy to perform the desired task, Thermal radiation, another name for radiative heat production, is the electromagnetic radiation that explains the heat exchange of energy by photons.

A medium is not necessary for the propagation of radiant heat, which is a method of heat transfer.

Since all substances above absolute zero have thermal energy, their constituent particles always move in some way. The object’s temperature is affected by the speed of the particles, and things with “normal” temperatures (less than 1000 Kelvin) radiate heat mainly in the infrared spectrum of light.

Until they collide with another particle, which absorbs its energy as kinetic energy, the photons released by these moving charged particles will move at the speed of light.

Until two systems at differing temperatures are in thermal equilibrium with one another, they will interact through exchanging radiant heat.

 Despite the fact that the exchange of photons does not end at equilibrium, it cannot be felt because the systems are at the same temperature.

Heat Loss Due To Current Leakages

When electrical energy is transferred to another shape and leakage current found during operation, it can cause heat loss.

An electrical current is connected to the movement of electrons through a material that allows for that movement.

The substance is known as a conductor. While certain conductors are superior to others, none are flawless, and all to some degree obstruct electron transport. Some of the energy contained in the electrons does not pass completely through when the flow of electrons is blocked.

The energy that was propelling the electrons ahead is changed into heat energy. In the filament of a light bulb, it can also be transformed into light energy.

Why Electrical Energy Is Transmitted At High Voltage?

Increasing transmission efficiency is the key motivation for using higher voltages while transmitting power from one place to another.

When power is transmitted over long distances, some of that energy is always going to be lost. To avoid or minimize the energy losses using high voltage while transmission.

Following justifications explain in detail why power is transmitted at high voltage:

  • In order to reduce power losses and voltage drop.
  • In order to cut down on the costs of power transmission.
  • To improve the transmission of electricity’s efficiency.

Reduction In Power Losses

Transmission lines have a power loss that is directly proportionate to the current that is flowing through them.

 Copper, aluminum, or alloys of those metals are typically used to construct the transmission lines. The resistance of the transmission lines itself is the primary contributor to the overall power loss.

Copper loss, refers to the power that is lost in the lines as a result of resistance.

The less current that is flowing, the less power will be lost. As a result, during the power transmission process, the voltage is increased to lower the current.

When it comes to sending the same amount of power over a greater distance, the power loss will be more significant when the transmission is done at a lower voltage.


When 100kW of power is transmitted over 1 kilometer at various voltage settings, let’s compute the power loss. Let’s say the conductor presents a 1-ohm resistance to the flow of electricity as an example.

When transmitted at 1100V:

A current flowing through a conductor= Power ÷ Voltage = 100kW ÷ 1100 V = 90Amperes

The conductor’s copper loss= I2 × R = 1002 × 1 = 10000Watts = 10 KiloWatts

When transmitted at 11000V:

A current flowing through a conductor = Power ÷ Voltage = 100kW ÷ 11000 V = 9 Amperes

The conductor’s copper loss = I2 × R = 92 × 1 = 81W = 0.81 kW

One thing to note is that power loss at 11000V is far lower than it is at 1100V. Because of this, power loss is significantly reduced when it is transferred at a higher voltage while still delivering the same amount of power from the power station to the load station.

The resistance of the transmission cables to the current passing through them causes a drop in voltage. Consequently, lowering the current and stepping up the voltage aid reduce voltage drop and enhancing voltage regulation.

Cut Down On The Costs Of Power Transmission

The current that will be transmitted determines the size of the transmission lines conductors.

The conductor’s cross-sectional area varies with the current. In order to transfer the same amount of power at a lower voltage, a significantly larger conductor would be needed than what would be required at a higher voltage.

As a result, the utilization of high voltage for the transmission of power contributes to a reduction in the number of conductors that is necessary.

It doesn’t take a genius to figure out that cutting down on the size of conductor that needs to be utilized might result in significant cost savings when it comes to high-voltage transmission. Increase the efficiency of electricity transmission

Efficiency Of Electricity Transmission

We can enhance the efficiency of power transmission by lowering the amount of power loss and the cost of the conductors and equipment that are necessary for power transfer.

According to the information shown above, transmitting electricity at a higher voltage can lead to a reduction in power loss and the cost of conductors, which ultimately results in an improvement in the effectiveness of the transmission of electricity.

For more details about overhead power lines read my article here.

What Is Difference Between Electrical Energy And Power?

The primary distinction between electrical energy and electrical power is that electrical energy refers to the amount of effort that must be done to initiate the flow of electric current across a circuit, whereas electrical power refers to the actual flow of electric current.

In contrast, the pace at which work—basically the movement of charges—is accomplished in an electrical circuit is the definition of electrical power. Additionally, the rate is determined by the unit of time that is being used.

Table Comparison of Electrical Energy and Electrical Power with Key Differences

Reference Points

Electrical Energy

Electrical Power



Within the context of an electrical and electronic circuit, the capacity to carry out electric work is the definition of electrical energy.

Electrical power can be defined as the “rate of work done per unit charge” or the “rate of energy transfer per unit time.” Both of these phrases refer to the same thing.

By letter representation


With a W or E, electrical energy is indicated.

P represents the electrical power.


Energy: (W)= (Energy × Time) or(Work × Time)


Power: (P)= (Work ÷ Time) or (Energy ÷ Time)

S.I Unit


Kilowatt-hours are the SI unit of electrical energy measurement (kWh).

The Watt (W) or Joule/Sec (J/s) is the SI unit for electrical power.



It is easily convertible into another type of energy (like heat, light, etc.).

It cannot transform into another type of power.

Function 1


You can produce or consume electrical energy.

Like energy, power cannot be produced.

Function 2


The energy produced can be saved for later use.

The two finest types of energy storage devices are batteries and generators.

The other storable items are unable to store electricity.

Electrical Energy Safety Tips

Electricity kills! This is for both expert electrical engineers and electricians as well as for non electrical workers.

So its necessary to follow safety rules when working with electrical devices. Below is some tips to keep in mind.

  • Only authorized persons to work with electricity.
  • Make regular and periodic electrical inspection for equipment.
  • Preventive maintenance program should improve safe conditions of the equipment and could prevent short circuits.
  • Always isolate power and use LOTO to prevent unwanted operation specially during maintenance.
  • Make sure to read manufacturer recommendations before operating any device.
  • Keep electrical equipment away from water.
  • Check portable cords and plugs before each use. Repair or replace any damaged parts.
  • Know where panels and circuit breakers are to make electrical isolation in case of emergency.
  • Never block access to panels and circuit breakers and keep them available.
  • Ensure that all electrical equipment are well grounded and check this grounding regularly.

For more Electrical Hazards And Safety details Visit My Site SafetyFrenzy.

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