Sources of Energy

Introduction
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 driving.
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 Sources
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 energy.

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 nuclear power.
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.

Renewable Energy
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 electrical energy.
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 electricity.
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.

by Adam Sykes