Introduction to Electrical Energy

Introduction to Electrical Energy

Introduction to Electrical Energy

Good day friends, well in my previous articles, I talked about the electrical power system and basically how they operate. I ‘ll love if you go check it: Here. Meanwhile, today, I will take you through the basic introduction to Electrical Energy. This literally entails the importance of Electrical Energy, Generation, and source of Electrical Energy and others, which will be of good interest. So, let’s start with Energy.

Energy, as we all know, can be of different forms. These include the light energy, sound energy, heat energy, mechanical energy and the electrical energy which our base is on. Honestly speaking, Energy is the basic necessity of living. It’s very essential for living, causing the nation to wholly depend on it. Meanwhile, thanks to the advanced improvement of technology, now, Energy can be converted from one to another.

Moreover, the electrical energy got more priority than others because eventually, everyone needs it for one thing or the other. Well, what I meant by electrical energy, is the power of electricity. So, you see that we both need electricity in almost everything we do. 

A country’s level of the standard can be known from its level of electrical energy consumption. In that, industries, factories, homes, offices, and shops require this form of energy to operate. So, the importance of electrical energy is not something that calls for debate. 

However, electrical energy when compared with other forms of energy has more superiority. Well, the reasons for this statement are stated below:

Importance of Electrical Energy

Very Convenient: Well, the convenient nature of Electrical Energy can be viewed from the fact that it can be converted to almost all other forms of energy. For example, it can be converted to light energy, through the electric bulb, where current passes through the filament to produce light energy. Again, it can be converted to heat energy, by subjecting an electrical current through a wire and by doing this, heat is being produced. Also, electrical energy can be converted into mechanical energy to impact motion on various machines. Well, this is achieved through what is known as an electric motor.

Great Flexibility: From this very angle, you can say that it’s more flexible because it can be transported through any material with the tendency of holding electric current. An example is the conductor/cable/wire. 

Easy Control: Energy is being operated electrically by machines. Nevertheless, the control mechanism of these machines is not rocket science. This implies that it can easily be controlled, especially that the starting and ending of these machines are done using just a button. Again, for that of an electric motor which helps in converting electrical energy mechanical energy. The speed of this type of machine can easily be varied. 


This form of energy is made available for almost everyone and for different purposes like domestic, commercial or industrial purposes. Regardless of your location, the system just needs to do, is to create a pathway for transmission. 

Cheapness: Among other forms of energy, the electrical energy cost less in consumption. Despite its availability, it’s still a more economical form of energy.

Cleanliness: Well, like others, it doesn’t produce any form of poisonous gas, smoke or fumes that tend to cause-effect to the atmosphere.

Transmission Efficiency: In most cases, the place where this energy is being generated is not usually close to the residential ground for consumption. So, for this reason, this energy has to be transmitted conveniently through an overhead transmission line with fewer losses. Therefore, we can say that the transmission efficiency is high.

Generation of Electrical Energy 

When you here about generating electrical energy, what should come to your mind is how electricity is being produced. Well, the simple analogy or definition to the generation of electrical energy is how another form of natural energy through the various natural source is being converted to produce electrical energy. 

This product can be pictured as a manufacturing system, where the raw material is being processed and converted into the desired goods. Similarly, the energy from some source is seen here as the raw material, being processed and converted into electricity as the desired finished product. 

However, the difference in the generation of electricity from others is that electrical energy is being continually produced due to its necessity. Unlike other manufacturing products which are produced at want and consumed as needed. Well, the electrical energy is not like that.

Meanwhile, due to this continual production, necessary and effective equipment is put into place. This is the reason why starting a generating station is very expensive because of the equipment in it. Therefore, this economical consideration should put in place for starting and maintenance by electrical power industries.

Electrical Energy 

Electrical Energy

The diagram above shows a simple constructive arrangement of a generating station. Well, you can figure out that the energy from the natural source is the main ingredient here. This energy is being converted into mechanical energy through a prime mover, which could be a steam engine or steam turbine. 

These energies can either be from the pressure of water, the force from wind, the chemical energy from fuel to produce heat which is exerted on the prime mover, which is then converted into mechanical energy. 

The mechanical energy from the prime mover is injected into an alternator. Meanwhile, an alternator which is a conversion machine helps to convert this mechanical energy into a three-phase electrical power. So, let’s see some of the sources of energy.

Various Energy Source 

We have seen that natural energy from different sources is the main element for the production of electrical energy. Therefore, it’s paramount that we take a brief study on these sources Energy. Meanwhile, they include:

  • The sun
  • Chemical energy from Fuels 
  • The Wind 
  • Water
  • Nuclear energy.

However, the production of electrical energy from the sun and that of the wind haven’t been achieved in a large commodity. This is sorely due to some limitations and we will look at these limitations as we go. So, practically speaking, the large scale production of electrical energy is from the other sources of energy. 

The sun: 

Well, we all know that the sun radiates Heat. This heat can be integrated into the production of electrical energy. Moreover, the sun is a primary source of energy. Also, for the heat emitted from the sun to be used to raise steam which will be needed for the prime mover. It has to be directed on a large surface region through the help of a reflector. Well, this process isn’t proportionate. This implies that, despite the large intensity of the sun, yet results in a small commodity of electricity. As such, it becomes part of the limitations. But let take a look at the other limitations:

  • Weather condition: it can only find application during the day, during the night or cloudy day, it becomes not applicable.
  • Proportionality: A small amount of electricity is produced from a considerable large surface area. So, it will require an extremely large surface area to produce a reasonable commodity of electrical power.
  • Cost: This Method of electrical energy production is uneconomical when compared to others.
  • Location: There is some location where the sun intensity is considerably low. So, it becomes a limitation to implement this method there. Nevertheless, for places where the sun intensity is reasonably high. Such, locations find more interest in this energy conversion method. 


The operational arrangement of using this form of energy is similar to the diagram above. Well, from our foundation in physics class, we know that when water is store in a place, it possesses potential energy due to the head created. This water turbine operates on this potential energy of the water. Then, converts it to mechanical energy which is then used to run the alternator to produce the electrical energy. 

Apart from the starting cost, another cost such as production and maintenance cost is low. This makes it favorable for usage. Again, the availability of water makes production continual. 

In addition, the whole process is the simplest and cleanest among others. 

The Wind: 

Technically, the form of operation of this method is quite different from the others. Here, it relies on a windmill and it’s used where the wind flow is experienced in a long time. Meanwhile, the pressure from the wind has to drive a windmill which is connected to a generator to produce electrical power. 

However, due to the fact that the wind flow isn’t continuous, and for continuity in the production of electrical power. The generator is then connected to batteries, to charge them. So, when the wind flow stops, power can still be produced. Well, the good thing here is that the generating and maintenance cost is quite negligible. Nevertheless, I made mention that there are some limitations amounting to the low utilization of this method. They include: 

  • Due to the uncertainty of wind flow, it becomes unreliable for production.
  • Variation in the out produced 
  • Invariably movement of the windmill will be required to produce a reasonable commodity of electrical power. But this can’t be attainable. 

Chemical Energy from fuels: 

Among all sources of energy, the fuel is considered as the chief main energy source. Fuel energy can be of different forms. It can be of a solid type, this is where coal falls into. Also, there’s the liquid fuel, an example is oil. Again, fuel can be classified as natural gas, that’s the gas fuel. 

Meanwhile, the chemical energy produced from fuel in the form of heat is used to drive the prime mover. An example of the prime movers used here is the steam turbine, steam engine, and the internal combustion engine. Moreover, what they simply do, is to convert the heat energy produced from the fuel into mechanical energy. This mechanical energy as we saw earlier, is being converted into a three-phase electrical power. 

Most generating stations used this method for electrical power generation compared to others. However, despite its favorable usage, its reserved nature is continuously reducing. Well, this form of energy source isn’t clean atmospherically. Although, the reliability is quite low compared to others. Also, speaking about the cost, the starting cost is fairly low but the maintenance cost is high. Again, the operational sequence is a bit complex when compared. 

Nuclear Energy: 

The amount of heat gotten from this source is quite huge. Although, this idea came into place during the ending of the second world war. It was then discovered that a very huge amount of energy was gotten during the fission of radioactive substances such as uranium. This was then channeled into the method of energy conversion. 

Well, from research, I discovered that the heat produced from one(1)KG of nuclear fuel amounted to about 4500 tonnes of coal. Meanwhile, the heat produced can be utilized by the prime mover. Moreover, the starting cost for setting up this system is the highest among all. But the running cost is the least. Another difficulty is the problem of disposal of radioactive waste after the whole process. 

Again, this process is the most complex and it will require well-trained personnel to handle it. Hence, it’s well reliable and clean. 

Units of Energy 

Introduction to Electrical Energy

Remember our physics class, we learnt the simplest definition for energy, as the ability to do work. Nevertheless, energy as we have seen, can take different forms. These forms include:

  • Mechanical energy 
  • Electrical Energy 
  • Thermal energy 

The fascinating part of this is that these energies can be converted from one form to another. So, for this very reason, it’s okay for a general unit to be assigned to all. The General international system unit for these energies is known as joule. But let see into individual units.

Mechanical Energy:

The unit for this energy is Newton(N)-meter(m). So, apparently, this can be considered as the one newton of force exerted on a body over a distance of one meter.

Electrical Energy:

Here, the unit is the watt(W)-second(s). In other words, it’s when there exists a potential difference of one(1) Volt across two conductors, and one(1) ampere of current is allowed to flow through them at one(1) second.

Well, when considering electrical energy, this unit is small, so we use a high unit like watt-hour and kilowatts-hour. That is:

1 watt-hour = 1 watt x 1hr = 1 watt x 3600sec = 3600 watt-sec

1 kilowatts-hour(KW-h)= 1000 watt x 1hr = 1000 watt x 3600 sec = 3600000 watt-sec

Thermal Energy:

The unit of heat can be of different form, calorie, British thermal unit(B.Th.U) and the centigrade heat units(C.H.U) 

Calorie: it’s the amount of heat energy required to raise the temperature of 1gm of water through 1 degree Celsius.

British thermal unit(B.Th.U): this is the amount of heat energy required to raise the temperature of 1 pound(Ib) of water through 1 degree Fahrenheit. 

Centigrade heat units(C.H.U): it’s actually the heat needed to raise the temperature of 1 pound(Ib) of water through 1 degree Celsius.

However, since we can convert all these energies into electrical energy. Therefore, we can also convert their units. You can note the following below. Well, I don’t wanna bug you with much calculation, so below are the conversion rate:

one(1) calorie = 4.18 joules

1 pound = 453 grams 

one(1) C.H.U = 1896 joules

While, 1 B.Th.U = 1053 joules 

Meanwhile, the usage of C.H.U, B.Th.U and calories is kind of obsolete. What you mostly find these days is the joule unit. 

Energy Efficiency 

We have seen that energy can be of different forms, including different sources of energy. However, our major concern here was lay on Electrical Energy. Meanwhile, we found out that we can convert any form of energy to get electrical energy.  

During the process of conversion, there are some losses. That is, the output energy at the end of the conversion is found not to be equal to the input energy before conversion. This, inequality in energy is due to the losses. 

Although, these losses can be known when we know the energy efficiency of the system. Therefore, we can say that the energy efficiency of the system is the ratio of the output energy to the input energy.

{ Efficiency } =\frac{ output energy }{ input energy }

Since power is the rate flow of the energy, then we can express the system energy efficiency as the ratio of the output power to the input power. 

{ Efficiency }=\frac{ output power }{ input power }

It’s expected to know that, the energy efficiency of the system is always less than 1 or 100%. 

Calorific value of fuel 

Technically, this is actually the total amount of heat produced when a unit weight of fuel undergoes complete combustion. Moreover, the calorific value of fuel varies. The calorific value of both solid fuel and liquid fuel can be expressed either in cal/gm or Kcal/Kg. While that of gaseous fuel can be expressed either in cal/liter or Kcal/liter.

The major constituents of solid fuel are carbon, hydrogen, oxygen, and ash. Examples of solid fuel include:

  • Anthracite coal
  • Bituminous coal 
  • Lignite 

Well, among all solid fuel listed above, Anthracite has the highest calorific value to be  8500Kcal/Kg. Having 90% of its constituents to be carbon, 3% as hydrogen, 2% as oxygen and 5% to be ash. Followed by bituminous solid, with a calorific value of 7600Kcal/kg. With 83% of its elements to be carbon, 5.5% as hydrogen, 5% as oxygen and 6.5% as ash. Then, lignite, which is the least among them. Lignite has a calorific value of 5000Kcal/kg. With 67% of carbon, 5% hydrogen, 20% oxygen and 8% as ash.

While an example of the liquid fuel are;

  • Heavy oil
  • Diesel oil 
  • Petrol 

Petrol has the highest calorific value of 11110kcal/kg. While both heavy oil and diesel oil have the same calorific value as 1100kcal/kg. Meanwhile, its main constituents are carbon, hydrogen, and sulphur. Although, petrol has only carbon and hydrogen. 

Also, for gaseous fuels, we have natural gas and coal gas. Coal gas has the highest calorific value of fuel compared to natural gas.

Advantages of Solid Fuel 

  • There is less danger of explosion during the process.
  • No unpleasant smell during the combustion process.
  • When compared with others, solid fuel seems to be fairly economical.
  • A similar burner can be used for almost all its types. Unlike liquid fuel that requires a special type of burning for combustion. This invariably makes it more economical than solid fuel.
  • Solid fuel doesn’t pose issues in a cold climate.

Advantages of Liquid Fuels

  •  The combustion process for liquid fuel is uniform and it’s easily controlled.
  • When compared with others, liquid fuel occupies a reasonable amount of space.
  • Liquid fuel has a controllable firing 
  • The burning process is less difficult because the amount of moisture present is less. Also, it can attain a higher temperature within a short period of time.
  • There exists little or no waste product for liquid fuel. However, this poses a problem of disposal for solid fuel. 


Well, we found out with reasons why electrical energy is the most important and utilized form of energy. Electrical energy can be gotten from other sources of energy, in which we saw the process of achieving it. We saw that, during this process of conversion, the energy experiences some losses. Meanwhile, this can be known through the system efficiency. Also, it was found that all energy has a relationship between each other and the basic unit of energy is the joule. In addition, we went further to talk about fuel and the Calorific value of fuels. So, let’s glance through some of the frequent energy asked questions. 

Electrical Energy: Frequent Asked Questions 

What is the primary source of energy?

The primary source of energy is the Sun. Although, during its conversion, there exist some limitations…

The most important form of energy

Electrical Energy is the most important form of energy among others.

What are the principal sources of energy?

The principal sources of energy include:
3.Nuclear energy 

The calorific value of solid fuel is expressed in?

The calorific value of both solid fuel and liquid fuel is expressed in cal/gm or kcal/kg. Although, that of gaseous fuel is expressed in cal/liter or Kcal/liter. 

What is the basic unit of energy?

The basic unit for Electrical Energy, Mechanical Energy, and Thermal Energy is Joule.

Why is electrical energy preferred over other forms of energy?

1. It is convenient 
2. Easily controlled 
3. High transmission efficiency 
4. Greater flexibility 
5. Cheapness 
6. Cleanliness 
7. Availability 

What is the main source of energy?

Among other sources of energy, coal act as the chief source of all.

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