We need energy to do a lot of things. Without it the world would be
very different. There would be no cars, no computers, no tv, no mobile phones,
in fact you wouldn't recongnise the world at all.
Energy cannot be created, all the energy in the universe is already in existence
in one form or another. We turn this potential energy into another form which we
can use to power different things like our tv or car.
Types of Energy
The way that energy is stored or released can be divided into different
types. Each type of energy can be converted into another type in some way. The
different types are:
Chemical Energy - Energy which is stored inside a fuel, e.g. Petroleum,
Food. The Petroleum is burned to fuel a car or a power station, food is used in
the body to power the different biological processes.
Potential Energy - Energy which is due to the existence of a possible
change to lower energy state. This is more easily described by examples, water
in a high-reservoir or a person about to jump out of a plane. The system has the
potential to produce energy, i.e the water can flow down from the reservoir and
the person can jump from the plane (with a parachute, of course!) without the
need of any energy input..
Kinetic Energy - Energy of movement, e.g a person running or car
Sound Energy - Energy due to the compression and rarefaction (uncompression)
of air or other medium that sound travels through. If you speak into a
microphone the sound energy is converted into movement of the microphone
components (kinetic energy).
Electrical Energy - Energy due to the movement of electrons from a
point of high potential to that of low potential, e.g. a battery.
Heat Energy - Energy due to the movement of particles in a medium, e.g.
water molecules moving around in boiling water.
Sources of Energy
These different types of energy can be found in various sources. These sources
can be divided into two-types: Renewable and Non-Renewable.
Non-renewable energy sources get used up as they get converted into usuable
energy in power stations. They are not completely non-renewable, as if you could
manage to wait a few million years then eventually they could be replenished.
The prime examples of this type of source are: Coal, Oil and Gas, also called
fossil fuels (they were produced from the decaying matter of past creatures).
These fuels, possessing "chemical energy", are burned in power stations. The
"heat energy" produced is used to heat large tanks of water, which then produce
steam. The steam turns a turbine, "kinetic energy", which has a set of large
magnets attached to it. The rotating magnets generate "electrical energy" in a
coil which can then be used for all your electric needs.
These fuels are also used to produce heat in your home, in fires, boilers and
for cooking food in your kitchen. They are used in vehicles in the form of
petroleum, diesel, or LPG. All these processes involve converting the "chemical
energy" into a usable form.
However, these sources have problems: Firstly, they are going to run out fairly
soon, and secondly, they cause pollution. Therefore, we need another source of
Nearly Renewable Energy
I call these sources nearly renewable as they do run out, but they can be
replaced within a lifetime. The sources in this section are wood/plants and
Wood can be burned much the same as coal, gas, and oil. When you have burned it
it is gone, however, you can re-plant more trees which will grow and can be used
for energy. Alcohol can be produced from wood and plants by fermentation, (same
process as for making beer), which can be used topower vehicles. It still
however has the environmental problems associated with burning fuels.
Nuclear power uses the energy released from atomic decay, when an element
changes from one isotope to another, or even another element. The energy from
this is great and lasts for years. The fuel can be reprocessed and more energy
retrieved. However, there is the problem of nuclear waste and fallout. The waste
produced from energy production of this typeis dangerous. It causes cancer and
other illnesses. Also, if there is a problem at a power station, there can be
serious consequences, as at Chernobyl, in the USSR, in 1986, when a power
station had a meltdown. The fallout from this can affect the surrounding area
for a great distance.
These are the way of the future if we wish to continue with our
electric powered lives. They don't run out and they don't pollute the enironment.
The main types of renewable energy are:
Wind Power - Wind turns a turbine attached to a dynamo which produces
Solar Power - Light from the sun excites chemicals in a panel which
produces the electrical energy.
Solar Heat Energy - Heat from the sun can be used to heat water in a
tank on your roof, to provide hot water for your house.
Water Power - Turbines in damns or rivers get turned by the force of
the water, powering a dynamo which produces electrical energy.
Tidal Power - The power of the waves can be harnessed to produce
Geothermal Power - The heat from deep inside the earth, can be used the
same way fossil fuels are used to heat water in a regular power station.
Hydrogen Fuel - We can burn hydrogen gas, (easily produced as found in
water), which burns cleanly to give just water as a by-product. Car engines are
being designed with hydrogen as a fuel.
Wind-up/Kinetic Energy - Wind-up clock radios and torches are already
available. You can even get torches you shake to charge up the batteries.
|All these renewable sources help to produce
power cleanly and efficiently. This helps the enviroment and can also help you
to save money if you pay the electricity bill. You can have your own personal
wind/solar power generator on the roof of your house, which can run the
electrical items in your house. If you drive you can now get hybrid cars which
run off petrol and electricity, as the car moves the battery is charged up for
use on short journeys and petrol is used for longer distance driving.
Adam Sykes lives in Wirral, UK. He has a Masters Degree, in Chemistry with
Pharmacology, from The University of Liverpool, UK and is currently doing
research to obtain his PhD qualification. He specialises in high performance
computing, with a further interest in the application of computing to
scientific research. His interests include films, music, tennis and walking.