A special "bobtail" truck is used to transport propane. "Bobtail" trucks are designed to run on propane. The back of the "bobtail" is much shorter than other tanker trucks used to transport gasoline or diesel.

A "cage" is a type of elevator used in a mineshaft to move miners and equipment.

A "can" is a building where nuclear reactors are contained. The picture above shows two dome-shaped cans at the North Anna Power Station. The shape and size of containment buildings may vary from station to station. The cans, or containment buildings shown above are 197 feet tall, with 50 feet being below ground level. They are 126 feet in diameter with walls up to 4.5 feet thick and constructed of steel reinforced concrete.

A catalytic cracker, or "cat cracker," is the basic gasoline-making process in a refinery. The cat cracker uses high temperatures, low pressure, and a catalyst to create a chemical reaction that breaks heavy gas oil into smaller gasoline molecules. With a cat cracker, more of each barrel of oil can be turned into gasoline.

A Christmas tree is a set of valves, pipes, and fittings used to control the flow of oil and gas as it leaves a well and enters a pipeline.

The "city gate" is the place where a company that sells natural gas receives the natural gas from the pipeline company. The "city gate price" is the sales price of the natural gas at this point.

"Coke" is a solid carbon made from coal. It is used to make steel. Another type of coke, "petroleum coke," is a refined product often burned to generate electricity.

A "dead man" is a buried anchor attached to a wire rope, or "guy line," that is used to keep a derrick standing upright. The white, dead man anchor pictured above is no longer buried because it is with an old rig that is on display at the Ocean Star Offshore Drilling Rig & Museum.

A biogas "digester" can convert animal waste into usable energy. On some dairy farms, the muck from inside the barn is collected and put into a large digester, or tank. Inside the digester, methane gas is separated from the liquid and solid waste. The methane gas can then be used to generate electricity to light the barn, or to sell to the electric power grid.

A "doghouse" is a small house located on the floor of an oil or gas rig that is usually used as an office or storage area.

The "face", or coal face, is the exposed area from which coal is extracted.

A horse head pump (shaped like a horse's head) is sometimes used to pump oil from a well.

A "pig" is a scraping tool that is sent through a pipeline to clean it out. "Smart pigs" have sensors that can detect cracks or corrosion in the pipeline, helping to prevent leaks.

A "roughneck" is a nickname for an oil rig worker.

The term "royalty" refers to the ownership rights of a mineral property (oil, gas, or coal). The owner is entitled to a share of the money made from oil, gas, or coal production on the property.

A scrubber is a technology that traps pollutants and keeps them from escaping into the air. Scrubbers in an electric power plant trap sulfur that is produced from burning coal or natural gas.

A "solar system" is technology that converts radiant energy from the sun into electrical or heat energy. In the picture above, the photovoltaic cells in the solar panels change radiant energy to electrical energy. The electrical energy can be used to power appliances in the building. Electricity not needed for the building may be sold to electric utilities using the electric grid.

A "tank farm" is a set of tanks used to store petroleum products.

To "trip" a switch or a circuit breaker means to switch-off the flow of electricity through a section of an electric circuit. A "trip" can disconnect electricity in a small circuit like a certain area of a house. It can also be more widespread, disconnecting a generating station from the larger electric power grid. A circuit may be "tripped" on purpose, in order to safely do electrical work. Sometimes a circuit gets "tripped" unintentionally, causing a power outage.

The "wellhead" is the point where crude oil and natural gas leave a well.

Electricity "wheeling" is when electricity is moved through a local grid for use in another area.

A "wildcat" is a well that is not drilled in a proven field.

A wind farm is a group of wind turbines used to generate electricity.

"Yellowcake" is another name for uranium oxide, named for its color and texture. After uranium is mined and separated from ore, it is made into "yellowcake" and shipped to a conversion plant for more processing. Uranium must first be converted into a gaseous form and then go through a long process of "enrichment" before it can be used by a nuclear power plant. Nuclear power plants generate around 20 percent of the electricity produced in the United States.