Alternating current. Also known as AC power, alternating current is electricity that reverses direction within a circuit. The electricity we use in our homes does this 120 times per second.
Appliances. Devices used in the home to perform domestic chores, such as a clothes dryer, dishwasher, refrigerator, and toaster.
Atmosphere. The layer of gases that surrounds the earth.
Atom. The smallest unit of matter. Scientists so far have found 112 different kinds of atoms. Everything in the world is made of different combinations of atoms.
Biomass. Material that is formed from living organisms, such as wood or agricultural wastes. Biomass can be burned to produce energy.
Carbon dioxide. A colorless, odorless, nonpoisonous gas that is a normal part of the air we breathe. Carbon dioxide is exhaled by humans and animals, and is absorbed by green growing things and by the sea.
Caulk. A thick paste-like substance used to fill up a crack or seam to make it watertight or airtight.
CFL. Compact fluorescent light.
Chemical energy. Energy that is released by a chemical reaction.
Chemical reaction. A process that changes one substance into another substance. Chemical reactions that take place during digestion change energy in food into substances that the body can use to do work.
Circuit. A circular path in which electricity travels.
Climate Change. Changes in temperature, rainfall, wind, and other aspects of the earth’s climate that last for an extended period.
Closed Circuit. An electrical circuit providing an uninterrupted, endless path for the flow of current.
Coal. A solid fossil fuel found in the earth. Coal is burned to make electricity.
Compact fluoresent lights. (CFLs) Lights that use a lot less energy than regular light bulbs. Also known as CFLs.
Conductors. Materials that allow electricity to flow through them easily. Water and most metals are good conductors.
Crankshaft. A main rotating shaft running the length of the engine that transmits power to the transmission for turning the wheels of a car.
Diesel engine. A type of engine invented by Dr. Rudolf Diesel at the end of the 19th century. It was originally designed to run on a variety of fuels, including vegetable oils.
Direct current. Electricity that flows in only one direction in a circuit. Batteries use direct current electricity, also known as DC power.
Electrical energy. A form of energy that arises from the flow of electrons.
Electricity. The flow of electrons.
Electrons. The basic particles that orbit the nucleus of an atom. The flow of electrons produces electricity.
Energy. The ability to change or move matter. It is sometimes also defined as the ability to do work.
Energy efficiency. Using less energy while getting more service from your appliances and equipment. You can do this by practicing energy-efficient behaviors or using energy-efficient technology, such as new lights and appliances.
Environment. All the natural and living things around us. The earth, air, weather, plants, and animals all make up our environment.
Fossil fuels. Fuels formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels. Oil, natural gas, and coal are fossil fuels. Gasoline and diesel fuel are made from fossil fuels.
Fuel. Any substance that can be burned to make energy.
Gas. A substance whose molecules are randomly moving so quickly that the molecules easily separate from one another. Gases will spread out and take on the shape and volume of whatever they are in--a jar, a room, or the atmosphere.
Generator. A device that generates electricity.
Geothermal energy. Energy that is generated by converting hot water or steam from deep beneath the earth’s surface into electricity.
Glaciers. Large bodies of ice that move slowly down a slope or spread outwards on a land surface.
Global warming. An increase in the earth’s temperature caused by human activities such as burning fossil fuels for energy. Burning these fuels releases carbon dioxide and other gases that make the earth’s natural greenhouse effect much stronger, trapping more of the sun’s heat in our atmosphere. Global warming is causing glaciers to melt and is changing sea levels and weather patterns.
Greenhouse effect. The greenhouse effect is the rise in temperature that the earth experiences because certain gases in the atmosphere absorb and radiate heat from the sun. This process occurs naturally and has kept the Earth’s temperature about 59 degrees F warmer than it would otherwise be. Current life on Earth could not be sustained without the natural greenhouse effect. Most scientists believe warming is happening because the greenhouse effect has become intensified primarily by the burning of fossil fuels, releasing an excess of carbon dioxide and other gases into the atmosphere.
Greenhouse gases. Carbon dioxide, methane, and ozone. These gases form a sort of clear layer around the earth that absorbs and radiates heat from the sun.
Hydroelectric power plants. The power plants that generate electricity when falling water makes a turbine spin.
Hydrocarbons. A compound that contains only hydrogen and carbon atoms. Natural gas is a mixture of hydrocarbons.
Hydrogen. A colorless, odorless gas that is the simplest and most common element in the universe.
Hydropower. Electricity that is generated when falling water makes a turbine spin.
kilowatt-hours (kWh). A unit of energy equivalent to one kilowatt of power expended for one hour.
Landfills. Place for trash and garbage disposal where the waste is buried between layers of earth.
Liquid. A substance whose molecules are in constant, random motion but do not move as fast as those in a gas. A liquid can take on the shape of its container but keeps the same volume, no matter what container it's in.
Mechanical energy. The energy of motion that can move objects from place to place.
Mercaptan. A chemical added to natural gas that makes it smell like rotten eggs so people will know if natural gas is leaking.
Methane. A hydrocarbon gas that is the main ingredient in natural gas.
Natural gas. A hydrocarbon gas found in the earth, composed of methane, ethane, butane, propane, nitrogen, carbon dioxide, hexane, heptanes, and pentane.
Nonrenewable fossil fuels. Fuels that can be used up because they cannot be easily made or “renewed.” Oil, natural gas, and coal are nonrenewable fossil fuels.
Nuclear energy or nuclear power. Energy that is released from splitting atoms of radioactive materials (such as uranium) and then harnessed to generate electricity.
Nucleus The center of an atom. The nucleus contains tiny particles called protons and neutrons. Orbiting around the nucleus are electrons.
Oil. A liquid fuel found deep in the earth. Gasoline and some plastics are made from oil.
Open Circuit. An incomplete electrical circuit in which no current flows.
Pilot Light. A small flame or spark used to ignite gas at a burner. Most newer appliances have electric pilots; older appliances have a small permanent flame.
Polyethylene. One of the components found in oil that is used for a variety of products such as containers, kitchenware, tubing, and sheets or films for insulation. Grocery store plastic bags are also made of polyethylene.
Power plant. A place where electricity is generated and sent over wires to where it is used.
Radiant energy. Any form of energy radiating from a source, such as heat from the sun or a campfire, or light from a bulb.
Refining facility. A facility that takes a crude substance (such as oil) and turns it into products such as electricity, fuels, or gases.
Renewable replaceable. If something is renewable it can be replaced or remade.
Renewable resources. Fuels that can be easily made or “renewed.” We can never use up renewable fuels. Types of renewable fuels are solar power, wind power, and hydropower.
Reservoirs. Natural or artificial ponds or lakes used for the storage of water.
Solid. Something that is hard and firm, and is not a liquid or gas. The molecules in a solid move slowly enough that they merely vibrate in place, allowing the solid to keep its shape and volume.
Solar cells. A solar cell is one that generates electrical energy.
Solar energy. Energy from the sun.
Solar hot water collectors. Part of a solar water heating system that allows water to be heated by the sun.
Solar panel. A device that collects energy from the sun and converts it to electricity. Solar panels are also known as “modules.”
Static electricity. A form of electrical energy that results from an imbalance of positive and negative charges.
Thermostat. A device that controls the temperature of a heating or cooling system.
Therms. A unit of measurement for the use of natural gas that appears on a person's monthly gas bill. Therms are the cubic feet of natural gas used, multiplied by a therm factor.
Transfer of energy. When one energy source moves or changes another source.
Transmission. The system in an automobile that transfers energy from the engine or motor to the wheels, causing the wheels to turn.
Turbine. A device used in the generation of electricity. It has a shaft (like a thick pole) with blades at one end and electromagnets at the other. Water, steam, or wind pushes the blades, making the shaft and the magnets spin very fast. The magnet end is surrounded by heavy coils of copper wire, and the spinning magnets cause electrons in the wire to begin to move, creating electricity.
Utility. A company or other organization that provides a public service, such as delivering electricity, natural gas, or water.
Weatherstripping. A type of material used to seal a door or window around the edges to keep the hot or cold air from coming in or out.
Wind energy. A renewable energy source that uses the force of the wind to spin turbines and generate electricity.
Geologist. A geologist studies the physical nature and history of the earth.
