Understanding Electricity

Electricity usage will increase in the future as we move from fossil fuels to clean energy. Examples of this transition are electric cars, solar panels, wind turbines, etc. The information below will help you understand the various terms and concepts of electricity.

What is Electricity?

Electricity is the flow of electrons. To understand electrons, we need to investigate atoms. An atom has a center, called a nucleus. The nucleus contains positively charged particles called protons and uncharged particles called neutrons. The nucleus of an atom is surrounded by negatively charged particles called electrons.

So, electrons are negatively charged and protons are positively charged. Therefore, the number of electrons in an atom is normally equal to the number of protons. However, when this balance is upset, an atom may gain or lose an electron. This free movement of these lost electrons constitutes an electric current.


What is an Electric Conductor/Insulator?

A conductor is a material that allows electrons to flow freely through it, making it useful for carrying an electric current. An insulator is a material that resists the flow of electrons, so it does not allow electric current to pass through it.


What is an Electric Circuit?

An electric circuit is a wire through which an electric current flows (conductor). We often think of an electric circuit as copper wire but the wire can be made from various metals. The coating on the copper wire does not let the electric current escape (insulator).


What is an Electric Current?

Current is the flow of an electric charge. Ampere is the measurement of the rate that current flows through a circuit (the number of electrons moving through the circuit per unit time — usually a second). Amperage is measured in units called amps.

Inside your breaker box, where your electric meter is located, there are circuits that are 15-amp, 20-amp, and 30-amp. The larger the amperage, the more electricity can flow through the circuit. While most household circuits are 15 or 20, large appliances like air conditioners and clothes dryers are 30-amp circuits.

What is Voltage?

Voltage is the “push” or “pressure” that drives an electric current across a given area per unit time. Power from an electrical grid is delivered to homes at two different voltages – 120 volts and 240 volts — because different home appliances operate at different voltages. Large, energy-hungry appliances like air conditioning units, electric ranges and clothes dryers operate at 240 volts, while most other devices like light bulbs, televisions and computers only need 120 volts.


What is Electrical Power?

Electrical power is the amount of electric energy an electric device consumes. Watt is a measure of electric power an electric device consumes per unit time. For The device may be a light bulb, a refrigerator, an air conditioner, etc. To calculate the number of watts, multiply voltage (push) times amperage (rate of flow of charge). The faster the electrons move through the circuit (current) and/or the greater the “push” or “pressure” (volts), the larger the number of watts produced.


What is Electric Resistance

Circuits are made up of wires. However, they are not perfect conductors (electricity doesn’t move through the circuit effortlessly). There is resistance that slows down the flow of electricity as it moves through the circuit. This resistance or friction is called Ohms.


An analogy is water moving through a garden hose. The pressure pushing the water through the hose is Volts. The speed of the water moving through the hose is Amperes. The resistance of the water moving through the hose is Ohms.


A kilowatt-hour (kWh)

A kilowatt represents 1,000 watts. A kilowatt-hour is equal to the energy of 1,000 watts working for one hour. Kilowatt-hours are determined by multiplying the number of kW’s required by the number of hours of use. For example, if you use a 100-watt light bulb for 15 hours a day, you have used 1,500 watts of power, or 1.5 kilowatt-hours of electrical energy.


What is Direct Current (DC)?

Direct current is the flow of an electric charge through a circuit that does not change direction. An example is a car battery. There is a direct flow of electricity from the battery that powers the starter (to start the car).

What is Alternating Current (AC)?

Alternating current is the flow of electrical charge through a circuit that periodically reverses. An example is the alternating flow of electricity from the grid that powers your home appliances.


What is an Electric Power Grid?

An electrical grid is a power generation, transmission and distribution network for the delivery of electricity from producers to consumers. It consists of power stations that generate electricity, electrical substations that decrease or increase voltage, and transmission lines that carry electricity long distances.


What is an Inverter?

An inverter is an electronic device that changes direct current (DC) to alternating current (AC). An inverter is used to change the direct current coming from solar panels to alternative current for use in the household.


What is a Transformer?

When electricity is generated, it travels along cables and wires to a transformer. The transformer changes electricity from high voltage to low voltage, or low voltage to high voltage.

Electricity can be moved long distances more efficiently using high voltage. High voltage transmission lines are used to carry electricity to a substation. A substation has a transformer that changes the high voltage electricity to low voltage electricity. From the substation, distribution lines carry the low voltage electricity to homes, offices, businesses, etc.

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