5 things about electricity

How is electricity made?

To produce electricity, energy must undergo a series of transformations before being transported and distributed in our homes.
There are several sources of energy. Certain renewable energies have been known for a very long time, such as solar and wind. Other, more recent energies such as marine energy or the thermodynamic process still require technological advances to be deployed.

#1.Electricity was discovered 26 centuries ago!

Thales, a Greek scientist, discovered it 6 centuries BC. He was rubbing a piece of amber with a cloth when he found that the stone succeeded in attracting small light objects like straw. Without knowing it, he discovered static electricity.

#2. Electricity is the means of transporting energy!

Electricity, like energy, is present in nature but we don’t see it. Except when there is a thunderstorm! Visible electricity is lightning.
Electricity is actually an energy carrier, that is to say, a means of transporting energy.

#3. How the atom gives an electric current?

Let’s start at the beginning: everything around us is made up of matter.
The matter is made up of atoms. And these atoms are made up of a central nucleus made up of protons and neutrons, and electrons that revolve around the nucleus like satellites around the Earth. When electrons move from one atom to another, they produce electricity.

#4. What are the sources from which electricity is produced?

Unclean Sources (Polluted)

• Steam coal

Coal-fired power plants operate by converting the combustible heat energy into electricity.

Coal plays an important role in generating electricity around the world, providing 41% of electricity in global power plants, and it is also called « steam coal » or « thermal coal », and this is done by following the following steps:

1. Transfer the coal to the factories, then burn it as it is converted into a fine-grained powder, so that the diameter of one grain is about 70 microns.
2. Water flows through thousands of narrow tubes in order to generate high heat and high-pressure steam, knowing that the temperature inside the water heater reaches 1300 degrees Celsius.
3. Transfer the steam to the turbine, where the blades rotate at a high speed, which causes the electrical transformer to rotate, which will generate electricity.

Charcoal power plants are characterized by low construction costs and they require less space than water plants.

 read also : 5 pieces of information about electric lines

Disadvantages of coal steam plants

• It produces large quantities of pollutants, which results in negative impacts on the surrounding environment and cause global warming, while the cost of operating them increases compared to water stations.

• These stations produce large quantities of energy, but they are often created close to the locations of coal, which is often far from the places where the electric energy is consumed, so the produced electric energy must be transferred to long distances.

• Clean sources

Nuclear

The known definition of nuclear energy is the energy released as a result of a nuclear reaction, specifically from nuclear fission or nuclear fusion. In practical terms, nuclear energy uses uranium fuel processed from the Earth to process steam to produce electricity.

Nuclear power plants use uranium to generate electricity, through the following stages:

Inside each nuclear reactor, there are small fuel discs that hold a lot of energy

• These tablets are inserted into tubes made of zirconium alloys of half a meter in length, which is a special type of metal that has a high resistance to corrosion, as these tubes are welded together in the form of fuel bundles
• These bundles are inserted into nuclear reactors where uranium is split to generate heat for boiling water and for generating steam and electricity.
• It is worth noting that this method is able to supply electricity to 100 homes in at least a year.

Nuclear power plants produce electricity in much the same way as conventional power plants. Stations generally use a source of heat to convert water into steam, then the vapor pressure turns on the generator and produces electricity afterward.

The difference between the stations lies in the type of heat source. In fossil fuel stations, the source of heat comes from burning coal, oil, or natural gas. In nuclear power plants, the main source of heat is the division of atoms or the so-called process of nuclear fission.

Nuclear reactors release heat, which in turn produces steam
Then the steam turns a turbine connected to an electromagnet called the (generator) and finally, the generator produces electricity.

 

Advantage of nuclear energy

1. Nuclear energy is the only fuel that can efficiently produce vast quantities of electricity-known as primary charging electricity-without releasing harmful gases such as greenhouse gases.
2. In addition, nuclear energy is among the sources that severely reduce environmental impacts, whether on the ground or natural resources, among all other sources of electricity production.
3. Nuclear power provided the world with a reliable and efficient source of electricity, and today there are more than 400 nuclear plants in more than 30 countries around the world.

What are the most common and wrong ideas about nuclear energy?

1- Explosion of nuclear reactors

The nuclear power plant cannot explode like a bomb, because its uranium enrichment level is very low. Nuclear power plants are designed for safely and efficiently producing electricity.

 

2- Nuclear energy is harmful to the environment.

When nuclear power plants are in operation, they do not produce any carbon emissions. Whereas more than a third of greenhouse gases are prevented from burning fossil fuels to generate electricity. Because nuclear power plants do not burn fossil fuels, they do not release these gases. Consequently, the use of nuclear energy helps achieve climate change goals, especially since nuclear energy can reduce carbon emissions annually by approximately 21 million tons.

3- Approaching nuclear power plants is not safe

After monitoring performance in hundreds of nuclear power plants in more than 30 countries, performance records demonstrate that nuclear power is safe. In addition, the World Association of Nuclear Energy Operators is responsible for tracking plant performance data such as safety system performance, fuel reliability, and industrial accident rates.

 Water

Water energy can be produced using electricity generators to obtain electricity from the movement of water. In ancient times, people used the power of river runoff in agriculture and milling of wheat, and today our workers re-direct the flow of rivers through water generators and build dams, as is the case in the River of a town. Sandouping « which is located in Liling, in the Chinese Republic, where the Three Gorges Dam is built and is currently considered the largest power station in the world.

The Sun

The principle of solar energy production is based on collecting sunlight and converting it into electricity, and this is done using solar panels, which are large flat panels consisting of a group of individual solar cells. Some kinetic energy sources contribute to the rotation of a loop or coil within a magnetic field so that this loop is connected to fixed wires.

The Wind

The operating principle of wind energy is relatively simple: the wind turns blades which in turn rotates the generator of the wind turbine. In turn, the generator transforms the mechanical energy of the wind into electrical energy of the wind type. Wind power is routed to the grid or to wind power storage batteries.

What is a wind turbine? 

Wind turbines are electricity producers. They « transform » the mechanic force of the wind into electricity.
A wind turbine includes:

•  A mast, which is used to hold the propeller high.
• A propeller made up of several blades (often 3) which will « catch » the wind and turn thanks to it.
• multiplier, which will increase the number of turns: when the propeller will make a turn, the axis of the multiplier will make 10. In this way, we can produce more electricity with less wind.
• A brake will slow down the propeller in the event of a strong storm to prevent it from falling off and taking off.
• A generator, which will transform the rotating force of the propeller shaft into electricity.
• A nacelle, which is a large block which contains the multiplier and the generator.

read also: Type of wind turbines 

Biomass

Energy from biomass is a renewable energy source that depends on the cycle of living plant and animal matter.

The oldest energy used by humans is the combustion of organic materials such as wood, plants, agricultural waste …

These materials, once burned, give off heat. This heat is used to heat water in a boiler that produces steam. the vapor released will allow the rotation of a turbine, which will drive an alternator producing electricity.

The electricity that cannot be contained will be sent to the high-voltage lines of the electricity distribution network.

Biomass by combustion

like all electricity production principles Waste is directly burned in to produce heat, electricity, or both (cogeneration). This concerns wood, waste from the wood processing industries, and agricultural plant waste (straw, sugar cane, peanuts, coconuts, etc.).

Household waste is treated by the urban waste incineration plant

Biomass by méthanisation

Household waste, animal manure, and slurry, sludge from sewage treatment plants, paper, and cardboard… are wastes which are first transformed into biogas, by fermentation thanks to micro-organisms (bacteria). This which is close to the natural gas and mainly composed of methane is burned.

Geothermal

Geothermal energy which results from the heat released by the Earth’s core and which escapes through the Earth’s crust. the average geothermal power density is very low (around 60 mW / m² compared to an average of 150 to 300 W / m² for solar radiation). But in certain geological zones (generally volcanic), the heat leaks can be much more intense and one can meet very hot water deposits exploitable to produce electricity (more than 150 ° C) via turbines with steam or for low-temperature heat use (less than 100 ° C)

#5.The electric risk

 1.Risk on wildlife

Power lines are one of the main causes of abnormal bird deaths in a large portion of African-European and Asian flight paths. Collisions with species threatened with extinction from the first supplement to the bird protection directives in many European countries, for example, Spoonbill – Platalea leucorodia, and the problem also exists in Africa.

In South Africa, for example, many species birds are threatened with extinction, such as the Blue crane and ludwigii Neotis, which are severely threatened because of the collision with the power lines.

read also : High voltage power  lines

 2.Risk on Humans

The physiological effects caused by the passage of electric current can be more or less serious. It is :

1. Destruction of cells
2. Internal burns
3. external burns
4. Tetany crises that can cause suffocation
5. Ventricular fibrillation that leads to heart attacks
6. Secondary trauma resulting from a fall or reflex movement.

Some values

• Chest resistance: 60 Ω
• Skin resistance:  500 Ω (1000 to 2500 Ω )
• internal resistance: 500 Ω
• Bone resistance: 300 000 Ω
• Immersed body resistance: 325 Ω

hand-to-hand resistance > than hand-to-foot resistance

( 500/750 Ω )

Human body resistance:1000 to 100.000 Ω

The intensity of Electric Current

The electric current enters the body through the pores of the skin hence the importance of sweating.
Thresholds :

1. Perception : 0.5 mA {*Eye : 0.02 mA  *tongue : 0.045mA
2. Non-let go: 10 mA  (tetanization)
3. mortals

• 30 mA: Asphyxia
• 75mA :Heart failure (3A)
• 1 A :cardiac arrest

Differences between electrification and electrocution

When the human body is crossed by an electric current, it is called electrification.
Electrocution is the flow of current through the human body that leads to death.

Electrical Risk Prevention

The prevention of electrical risk either at home or at work is based on regulatory provisions. It concerns the securing of electrical installations and equipment, right from their design. The goal is to avoid contact, whether direct or indirect, with bare live parts or accidentally live parts. In addition, the equipment must comply with the regulations in force in order to protect users.