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Specialists in Diesel Generators and Independent Energy Solutions
Electricity Basics
Independent energy solutions are all about getting the electricity that you need to run your life. To help us to work with you to find the best solution to your independent energy needs it’s helpful if you understand the concepts and terminology of electricity.
Electricity is the movement of electrons. Electrons are sub-atomic particles that exist in the atoms of all materials.
Conduction
Electrons are only able to move through some types of materials; these types of materials are called conductors. The best conductors are metals. The atoms in metals form a lattice in which all of the electrons are shared amongst all of the atoms, so the electrons are able to move around easily.
One of the best metal conductors is copper, because electrons can move through it with very little friction. Other metals will conduct electricity but the electrons will encounter greater friction as they move. Many other non-metal materials conduct electricity, but usually with more friction than metals.
In many materials the electrons are tightly bound to each molecule (a molecule is multiple atoms joined together), and are not able to move. Because the electrons in these materials can’t move, they don’t conduct electricity. These materials are called insulators.
Characteristics of Electricity
Electrons don’t move through a conductor by themselves; they have to be pushed by a force. That force is called electro-motive force (EMF). When we use electricity the electro-motive force is usually provided by either a battery or an alternator.
The strength of the electro-motive force is measured as its voltage (the unit of measurement of electro-motive force is the Volt.)
The higher the voltage, the stronger the force is that pushes the electrons along the conductor.
The movement of the electrons along a conductor is called current, and the rate that the electrons are pushed along a conductor is called amperage (the unit of measurement is the Ampere.) You can think of the amperage as the quantity of electrons that pass a point on the conductor in a period of time.
The friction that electrons must overcome as they move through a conductor is called resistance (the unit of measurement of electrical resistance is the Ohm.)
The electro-motive force (the voltage) overcomes the resistance and moves electrons along the conductor. As electrons move along the conductor, the resistance causes heating.
Electrical Power
When voltage pushes electrons along a good conductor a lot of electrons will move along quickly and a large current will result. Because there is little resistance in a good conductor there will be little heating. If a poor conductor is used, more voltage will be required to overcome its greater resistance to make the same amount of current flow, and the increased resistance will result in heating. This means that to produce powerful heating both high voltage (needed to cause the high amperage) and high amperage are required; so electrical power is a combination of both voltage and amperage. The unit of measurement of electrical power is the Watt.
Power and Energy
An electric fan heater heats your home by pushing an electrical current through a resistive conductor, which gets hot. The electrical power heats the heater to a high temperature which heats the air surrounding it.
If you leave the fan heater switched on for a minute it will make no noticeable difference to the temperature of your home. If you leave the heater switched on for an hour it will increase the temperature of your home. The power of the heater (the Watts) is the same whether it is switched on for one minute or one hour, but it‘s only when it has been working for a long time that it makes a difference to the temperature of your home.
The amount of work that the heater does is a combination of both the power of the heater and the length of time that it operates.
The amount of work that the heater does is the quantity of energy that it uses to heat your home. The unit of measurement of electrical energy is the Watt-hour.
People often confuse electrical power with electrical energy. Remember: the power of the heater (in Watts) is the rate at which it heats your home; the energy that the heater uses (in Watt-hours) is the amount of heating
that it does for your home.
In summary:
⦁ the force that pushes electrons along a conductor is electro-motive force, and is measured in Volts
⦁ the resulting flow of electrons is the current, and is measured in Amperes
⦁ the friction in the conductor that must be overcome is resistance, and is measured in Ohms
⦁ the rate at which work is done is the electrical power; it’s a combination of both the voltage and the amperage, and is measured in Watts
⦁ the amount of work that is done is the electrical energy; it’s a combination of both power and time, and is measured in Watt-hours.
In use, all these units of measurement are commonly abbreviated to
letters:
⦁ Volt is abbreviated to ‘V’
⦁ Ampere is commonly shortened to ‘Amp’ and abbreviated to ‘A’
⦁ Ohm is abbreviated to the Omega symbol ‘Ω’
(You won’t see Ohms used very often)
⦁ Watt is abbreviated to ‘W’
⦁ Watt-hour is abbreviated to ‘Wh’
Both Watt and Watt-hour are small units for household use (one Watt-hour of electrical energy will run your electric jug for less
than two seconds), so you will commonly see these units used with the multiplier-prefix ‘kilo’ or the letter ‘k’, which means one-thousand. Most homes use between ten and twenty kiloWatt-hours (kWh) of electrical energy each day.