Electricity is everywhere in our lives. It lights up our homes, cooks our food, powers our computers, television sets and many other electrical devices…
But what is electricity, where does it come from, how does it work? The following is the science of electricity in a very small portion…
Thermal power plants
Matter is made up of atoms, and atoms are made up of smaller particles. The three main particles making up an atom are proton, the neutron and the electron. Electrons spin at the centre, or nucleus of atoms, exactly the same way as the moon spins around the earth. The nucleus is made up of neutrons and protons. Electrons contain a negative charge, protons have a positive charge. Neutrons are neutral-they have neither a positive nor a negative charge.
Each atom has a specific number of electrons, protons and neutrons. But no matter how may particles an atom has, the number of electrons usually needs to be the same as the number of protons. If the numbers are the same, the atom is called balances, and it is very stable. Electrons can be made to move from one atom to another. When those electrons move between the atoms, a current of electricity is created. Man has used his ingenuity to harness these atoms for his benefit, on a commercial scale we produce electricity through large thermal electric power plants.
Thermal electric power plants work in a similar manner, regardless of whether they are powered by coal; natural gas; or other fossil fuels; nuclear; biomass or geothermal energy. A thermal power station is a power plant in which the prime mover is steam driven. Heat, (energy) is used to boil water creating super-heated steam. This pressurised steam is run through a turbine which drives an electrical generator, which converts the rotating mechanical energy to electricity (electrical energy). The low pressure steam is condensed back into to water, and then recycled to be heated up again into steam. The waste heat from condensers in most cases is expelled into the atmosphere, or into bodies of water. In some cases it is used to heat buildings, especially during the winter in northern climates.
Power plants that burn fossil fuels or biomass expel CO2
You will find that commercial electric utility power stations are usually constructed on a large scale (as mentioned above) and designed for continuous operation. Power plants that burn fossil fuels or biomass expel CO2 (carbon dioxide) into the air, which is considered by many scientists to be a leading cause of global warming. There is an on-going debate about the best source of fuel to power our plants. Nuclear power plants use nuclear energy to heat the water to make electricity, still others called geothermal power plants, use steam or hot water found naturally below the earth’s surface without burning a fuel.
Once the electricity is produced at thermal power stations it has to get to the customers. Most of our country, cities and towns, are criss-crossed with power lines that carry the electricity to our homes. We can then switch on at the other end with never a thought of how it actually got there.