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. 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.

Coal

A solid fossil fuel found in the earth. Coal is burned to make electricity.

Compact fluorescent lights

Lights that use a lot less energy than regular lightbulbs. Also known as CFLs.

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.

Electrons

The basic particles that orbit the nucleus of an atom. The flow of electrons produces electricity.

Energy

Energy is 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.

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. The greenhouse effect (warming of the earth) has been causing glaciers to melt.

Greenhouse effect

The warming of the earth that results when solar energy is trapped by the atmospheric gases. This causes the earth’s climate to change in unpredictable and harmful ways.

Greenhouse gases

Carbon dioxide, methane, or ozone. These gases form a sort of clear film around the earth that traps heat from the sun, known as the greenhouse effect.

Hydroelectric power plants

The power plants that generate electricity when falling water makes a turbine spin.

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.

Landfill

Place for trash and garbage disposal where the waste is buried between layers of earth.

Mechanical energy

The energy of motion that can move objects from place to place.

Methane

A hydrocarbon gas that is the main ingredient in natural gas.

Natural gas

A fossil fuel found deep in the earth. Natural gas is often found with oil.

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

The energy that is generated from splitting atoms of radioactive materials, such as uranium.

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.

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.

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.

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.