Energy Dictionary

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The Energy Dictionary consists of an Index of Terms with hotlinks to definitions. After each definition is a hotlink to return to the Index of Terms.

Index of Terms
Acid Rain





Definition of Terms
Acid Rain: When fossil fuels are burned, sulphur dioxide and nitrogen oxides are released into the air. Rain combines with these oxides in the air and becomes acidic. Acid Rain collects in lakes, streams and soil and makes it hard for the plants and animals that live in these environments to survive.

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Ampere or Amp: A measure of electrical current used to describe the number of electrons moving through a wire in one second. Electrons move through a wire much like water flows through a pipe.

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Atoms: The smallest stable units of matter. Atoms contain protons, neutrons and electrons, but these smaller particles are not stable by themselves.

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Ballast: A device found in fluorescent lights. When a fluorescent light is turned on, the ballast produces a high voltage across the gas in the tube. This voltage charges the gas until it lights up. The ballast then sends a low current through the gas so it gives off light using a small amount of energy.

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BTU: Abbreviation for British Thermal Unit, the measure of heat energy in the English system. A BTU is the amount of energy it takes to raise the temperature of one pound of water by one degree Fahrenheit.

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Calorie: The unit used to measure heat energy in the metric system. A calorie (small c) is the amount of energy it takes to raise the temperature of one gram of water by one degree Celsius. A Calorie (large C) is the amount of energy it takes to raise the temperature of one kilogram of water by one degree Celsius. The energy content of food is expressed in Calories.

Carbon Dioxide (CO2): Carbon dioxide is produced when fossil fuels are burned. It is also a naturally occurring gas that is taken up by plants. CO2 contributes to the Greenhouse Effect.

CFC's: Chloro-Fluoro-Carbons, chemicals that are circulated in air conditioners and refrigerators to transfer heat from one location (usually inside a room or container) to another (usually the outdoors). CFC's were used in aerosol cans but this is now illegal in the United States because they contribute to the Greenhouse Effect.

Combustion: The process of burning. Combustion produces airborne Emissions and solid waste such as ash and sludge.

Conductors: Materials that electrons travel through freely. The best Conductors are metals such as copper which are used to make the wires that conduct Electric Current from generation facilities to consumers. Water, people, animals, trees and the ground can also be Conductors.

Conservation: Protecting something from loss or depletion. Energy Conservation involves using energy resources carefully by implementing energy efficient technologies and by avoiding unnecessary uses of energy.

Efficiency: The amount of useful Work done by a given amount of Energy. An efficient light bulb uses most of its energy to produce light, not heat. An efficient car goes many miles on one gallon. An efficient refrigerator uses less electricity to keep food just as cool. An efficient power plant produces more electricity from the coal or oil it burns or wind, sun and water it harnesses and creates less heat and pollution in the process.

Electric Current: The movement of electrons through a material. Electric Current is measured in units of Amps. See also Conductors and Resistors.

Electric Meter: A device that measures the amount of electric energy used by a home or apartment. Electric Energy is measured in units of Kilowatt-hours.

Electric Meter Reader: A person who works for the electric utility company to keep track of how much electric Energy a household or apartment uses. Each month, the Electric Meter Reader reads the number of Kilowatt-hours recorded by Electric Meters. This number is used to calculate monthly electric bills.

Emissions: The gases and airborne particles produced during Combustion.

Energy-Efficient Lights: Lights that require a small amount of Power (Watts) and produce a large amount of useable light. Light intensity is measured in Lumens. Fluorescent Lights are efficient because most of the power they require is used to produce light instead of heat. Reflectors can improve the Efficiency of any light bulb by directing light to where it is needed.

Energy: The ability to do Work.

Fossil Fuels: Fuels such as coal, oil and natural gas that were formed over millions of years from decayed plants and animals. When large volumes of these fuels are burned (see Combustion), the by-products that are released into the air (called Emissions) can cause serious pollution problems such as smog and Acid Rain.

Fluorescent Lights: These bulbs produce very little heat while giving off light. Lights that make a phosphor glow. The inside surface of fluorescent bulbs is coated with a special white material called a phosphor. Electric Current is used to energize the atoms in the phosphor so they give off light. Compare with Incandescent Lights.

Fuel Efficiency: The amount of useful Work done when a given amount of fuel is burned. A Fuel Efficient car travels more miles on one gallon of gas than a conventional car.

Generator: A device that uses mechanical Energy to create electrical Energy.

Global Warming: A gradual increase in the average air temperature on the planet, thought to be caused by the Greenhouse Effect. Extensive efforts are being made to determine the extent to which human activities are contributing to Global Warming.

Greenhouse Effect: What happens when Energy from the sun gets trapped in the atmosphere. Gases like Carbon Dioxide and CFC's prevent solar Energy reflected by the earth from escaping into space. In houses or cars, glass or plastic traps heat from the sun, resulting in a small scale Greenhouse Effect.

Horsepower: The English system unit used to measure mechanical Power. One Horsepower is equal to 746 Watts.

Incandescent Lights: Light bulbs that use Energy from moving electrons to heat a wire until it glows.

Insulator: A material that electrons cannot flow through. Plastic, fiberglass, thick paper and cloth are examples of Insulators.

Kilowatt: A unit of electrical Power equal to 1,000 Watts

Kilowatt-hour (kWh): A unit of electrical Energy equal to the amount of Energy consumed by electrical appliances that use one Kilowatt for a period of one hour. The cost of electrical Energy is expressed in terms of $/kWh.

Line Worker: A person who works for the electric utility to repair Transmission Lines.

Lumen: A unit used to measure of how much light is being produced.

Megawatt: A unit of electrical Power equal to 1,000,000 Watts.

Nuclear Reaction: A way to produce heat that is different from combustion. A Nuclear Reaction occurs when the center of an atom (called a nucleus) either splits apart or joins together with the center of another atom.

Power: The rate at which Energy is consumed. Electrical Power is measured in Watts. Heating and air conditioning Power is measured in BTU per hour. Motor Power is measured in Horsepower.

Power Plant: Power Plants are industrial areas where electrical Energy is produced and managed. Power Plants often burn coal, oil, natural gas, wood or garbage to create steam. Some Power Plants concentrate solar radiation or initiate and control a Nuclear Reaction to make steam. Steam then turns a Turbine which spins a Generator to make electricity. Windmills and photovoltaics are used to make Power Plants that do not require steam.

Radioactive Waste: Hazardous materials resulting from Nuclear Reactions.

Renewable Energy: Energy from sources such as the sun, wind, water and wood which are a direct result of the climate in a given geographic area.

Resistor: A material that resists the flow of electrons. Using the water analogy, a small pipe would be considered a Resistor while a large pipe would be considered a Conductor.

Substation: A building where Transmission Lines from the Power Plant are switched to Transmission Lines that serve consumers. The Voltage of the electrical Energy in the Transmission Lines is decreased at Substations.

Sustainable: Something that can continue indefinitely. To build a Sustainable society, we must be careful about how we use Energy to avoid ruining the environment for ourselves and other animals and plants.

Transformer: A device that changes the voltage of electrical Energy in Transmission Lines. When electrical Energy needs to be transmitted over long distances, its voltage is increased by step-up Transformers. Before the electrical Energy enters a building, its voltage is decreased by step-down Transformers. These step-down Transformers are located at Substations.

Transmission Line: The electrical Energy that is created at Power Plants travels to the places where it is used through Transmission Lines. You often see Transmission Lines along roads, but sometimes they are buried underground. Transmission Lines are also called power lines.

Turbine: A rotary engine that is turned using the Energy in a moving gas or fluid such as water, wind or steam. Turbines are usually made with a series of curved vanes on a central rotating spindle.

Volt: A unit used to measure the pressure that is available to move electrons. Voltage is like water pressure. Flashlight batteries store electrons at 1.5 Volts, car batteries at 12 Volts. The electricity available from wall outlets has a pressure of 120 Volts behind it.

Watt: A unit used to measure electric Power. The Power rating of an electrical device in Watts expresses the amount of energy the device consumes in one second. Watts are equal to Volts times Amperes.

Work: The transfer of Energy from one form or system to another. The amount of useful Work done in a given amount of time is equal to Energy consumed times Efficiency.

Link to Biodiversity Unit Homepage

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Link to JNCASR Homepage

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