Lesson #5
Electricity Generation
What is electricity?
Electricity is briefly defined as the flow of electric charge. Electricity is a natural phenomenon that occurs throughout nature and takes many different forms.
It is a form of energy that results from the existence of charged particles either statically as an accumulation of charge or dynamically as a current.
Electricity has a wide range of purposes including powering homes, industries, and various devices.
To understand how electric charge moves we first need to understand about atoms.
Everything in the universe is made up of atoms. Atoms are made of even smaller particles.
The center of an atom is called the nucleus. It is made of protons, neutrons, and electrons.
The protons and neutrons are very small but electrons are even smaller. Protons and electrons carry an electric charge. Protons have a positive charge and electrons have a negative charge. The neutrons carry no charge.
Every atom has atleast one proton in it. The chemical element depends on the number of protons in an atom. This count of protons is called the atom’s atomic number.
The neutrons keeps the protons in the nucleus and determines the atom’s istope.
The number of Electrons is equal to the number of protons in the most stable balanced state.
The electrons on the outer orbit of the atom are called valence electrons. With enough outside force, a valence electron can escape orbit of the atom and become free.
As defined earlier electricity is defined as the flow of electric charge. Charge is a property of matter and is measurable. Charge is in two types: positive (+) or negative (-).
In order to move charge we need charge carriers.Electrons always carry a negative charge, while protons are always positively charged. Neutrons (true to their name) are neutral, they have no charge. Both electrons and protons carry the same amount of charge, just a different type.
Free electrons allow us to move charge, which is what electricity is all about.
The electrons on the outer orbit of the atom are called valence electrons. With enough outside force, a valence electron can escape orbit of the atom and become free.
As defined earlier electricity is defined as the flow of electric charge. Charge is a property of matter and is measurable. Charge is in two types: positive (+) or negative (-).
In order to move charge we need charge carriers.Electrons always carry a negative charge,
while protons are always positively charged. Neutrons (true to their name) are neutral, they
have no charge. Both electrons and protons carry the same amount of charge, just a
different type.
Free electrons allow us to move charge, which is what electricity is all about.
Methods of electricity generation and their environmental impact
Electricity is a type of energy that occurs due to charged particles and can be either static or electrical current. Let us understand more about electrical current ie electricity generation and the various methods used for the same.
Electrical energy can be generated from various sources such as oil, gas, nuclear or solar energy. Some of them are the raw materials for energy and some like solar are forms of energy which get then converted into electrical energy.
Wind Energy
Wind energy is electricity generated through the use of wind turbines. The motion of the wind rotates the turbine blades and the rotation connects to gears linked to a generator. The generator then generates electricity.
Water Energy
The electricity generated from water is in the form of wave power, tidal power and hydroelectric power. The rise and fall of waves on the ocean’s surface results in wave power.
During high and low tides large amounts of water move in and out of the river. A tidal barrage forces water between small gaps to make use of the kinetic energy of a tidal
movement. The gaps in the barage contain electrical generators which generate electricity.
Hydroelectric power is where a large dam is built to block water in a higher location. These dams take advantage of the gravitational potential energy of water being blocked. This water is sent through a generator to generate electricity.
Solar Energy
The electricity generated by the sun shining on solar cells or photovoltaic cells is called solar power. The photovoltaic cells convert energy from light waves to electrical energy.
Biofuel
Biofuel requires biological matter to be burnt to generate electricity.
Fossil Fuels
The main sources of fossil fuels are coal, oil and natural gas. Electricity production in India is mostly through coal thermal power.
These fossil fuels contain a store of chemical energy that when burned becomes heat energy.
Burning fossil fuels generates huge amount of carbondioxide and thus not the best ways of generating electricity.
India’s current electricity mix uses 77% of fossil fuels of which 72% comes from coal, 4% from natural gas, and 1% from oil. Traditional biofuels like wood burning are used for generating 20% of the electricity needed. Renewable sources are still a small percentage and India has a long way to go if it wants to meet its target of generating half its electricity from renewables by 2030.
The oil supply situation at current levels is not so favorable and at the current levels of production, the domestic oil sources will last for another 23 years.
Nuclear Energy
Electricity generated with nuclear fuels is called Nuclear Energy. Nuclear reactions generate thermal energy used to create steam from water and drive turbines wich finally generate electricity.
The local uranium ores in India are of a very low quality thus making the production and extraction process more costly. Imports of uranium are not easy because of stringent guidelines by Nuclear Suppliers Group.
The main problem of electricity generation in India is in its structure. The role of coal is emphasized, while the share of renewable energy sources (RES) including hydropower is relatively low.
India needs to diversify its resources since dependence on coal has several disadavantages like high carbon emissions, the high cost of the transportation of coal to the final consumer destination, the high cost of the maintenance of a large electricity grid, the significant impact of coal mining on the environment, and the growing dependence on imports from other countries resulting in possible security threats.
Greenhouse gas emissions are the biggest impacts of electricity generation. Coal is the worst carbon emitter followed by natural gas. Water usage is another big environmental impact .
All thermal plants use water as a cooling fluid that allow electricity to be extracted from heat energy.
Suggested Activities
- Research on any method of electricity generation like solar, hydroelectric and document your understanding on the detailed process. If possible conduct a field visit to further your understanding.
- Study the electricity generation in any household/community and suggest ways to reduce the electricity consumption or adopt renewable methods of electricity generation.
Additional learning sources
- Electricity Production – Burning Fossil Fuels
- Energy 101: Electricity Generation
- How does electricity generation impact the environment?