Gas and coal make electricity through combustion. When coal is used, it is pulverized into a fine powder. New technologies can even gasify coal. The fuel burns in a large furnace that superheats water into pressurized steam. The steam carries tremendous force, which is used to turn turbine blades that spin electric generators. The big tower cools water back down after becoming steam. Byproducts of combustion, called emissions, are monitored and removed in part by scrubbers and precipitators. Ash from the coal can be recycled into concrete or wallboard. Studies are under way to lower carbon dioxide releases, another byproduct of combustion. Combined cycle gas plants vary somewhat from the design shown here and gas produces less emissions.

Coal power plant demo furnace condensor fan steamPipe
A

Steam Generator

Here, water is heated to steam inside a system of tubes. The steam will drive a turbine.

B

Burner

This nozzle introduces the right level of pulverized coal.

C

Forced Draft Fan

This fan provides air to the boiler for the coal-combustion process and helps push exhaust gas through the boiler.

D

Furnace/Boiler

Welded steel pipes make up the panels of the boiler walls. Folds of tubing inside the boiler force the steam to a temperature many times above the boiling point. The exhausted steam, is used again at a lower pressure stage of the turbine to save on fuel use. The final heat exchange in the boiler uses heat from exhaust gases to raise the temperature of water being fed into the boiler to increase boiler efficiency.

E

Bottom Ash

A combustion byproduct that collects on the walls and bottom of the boiler. Bottom ash is a ceramic-like material that can be recycled in asphalt, concrete, insulation, and cleaning grit.

F

Turbine

Fan blades attached to a shaft are spun by expanding steam, converting the kinetic energy of the steam into mechanical energy.

G

Generator

Electricity starts here where the generator transforms mechanical energy into electric energy.

H

Condensor

Electricity starts here where the generator transforms mechanical energy into electric energy.

I

Cooling Water

Outside water is used to condense the steam after it leaves the turbines. The outside water can be recycled by spraying it into a large tower where drafts cool it back down. Different designs are used, sometimes you see hyperbolic towers at coal plants or any plants that uses steam to make electricity.

A hydro plant uses water and gravity as fuel to create electricity. The water is stored in the reservoir behind the dam. When power is needed, gates open and gravity takes the water in the reservoir through the dam, moving turbine blades like an old-fashioned water wheel (but much faster and more efficiently). Hydro power removes no water from the river and produces no solid wastes or air emissions.

spout fan
A

Water from the reservoir (A) passes through the penstock (B), a large pipe that goes to the powerhouse.

B

Water from the reservoir (A) passes through the penstock (B), a large pipe that goes to the powerhouse.

C

The flowing water turns the blades of turbine, a sort of modern water wheel that connects to the generator (D). The generator has magnets and wire inside that when turned round and round produce electricity.

D

The electricity from the spinning generator (D) is conducted to the power transformer, where voltage is increase. The high-voltage electricity is then fed into transmission lines for distribution.

E

As water leaves the turbine, it passes through a draft tube (E) and into the tailrace (F) where it returns to the river below the dam just the way it started.

F

As water leaves the turbine, it passes through a draft tube (E) and into the tailrace (F) where it returns to the river below the dam just the way it started.

Nuclear plants make electricity by heating water into pressurized steam that spins turbine blades and generators. Heat comes from the nuclear fission process. Nuclear plant designs vary in some details; this one is a pressurized water reactor.

condensor bubbles fan steam
A

Reactor Vessel

Fuel rods with radioactive isotopes create heat in a controlled nuclear fission process within the vessel.

B
Control Rods

Control Rods

Metal rods, plates, or tubes pace the nuclear reaction to achieve desired temperatures. These rods contain a material, such as hafnium or boron, that absorbs neutrons, the particle that spawns more fissions.

C

Pressurizer

A tank used to maintain the water pressure within the reactor.

D

Steam Generator

The vessel used in some reactor designs to transfer heat from the reactor coolant system (red) to the steam system (grey). This heat exchange design keeps the two water systems separated and isolates the nuclear process used to heat the water from the mechanical process used to generate electricity.

E

Turbine

A turbine is a rotary engine comprised of curved vanes on a shaft (like a fan), turned by steam. Turbines are an economical way to turn large electrical generators.

F

Generator

Coiled copper wires rotate rapidly in magnetic fields to create the flow of electrons known as electricity.

G

Condenser

Cool water in pipes brings the exiting steam from the turbines below the boiling point, turning it back into water that can be recirculated.

H

Cooling Tower

Water from a natural source, like a river or lake, circulates through the condenser and back into a cooling tower. Some, called hyperbolic towers, have this shape to create a cooling draft. Hyperbolic towers are not unique to nuclear power. They are used in other plants, too. And some nuclear plants use towers of other designs.

  1. Captain Cautious

    Line Crew - Builds lines so that electricity can get to houses, businesses, schools and hospitals. People who like working outside and building things with their hands really like these jobs.

    Captain Cautious knows a lot about energy!
  2. Dr. E

    Dr. E
  3. Emerald

    Emerald
  4. Savvy and Squander

    Savvy and Squander
  5. Louie

    When you grow up, we can teach you how to be a line worker, plant technician or an engineer.

    However, there are other things you will need to learn along the way: How to get along with others, teamwork, following instructions, telling the truth, completing your work on time and doing a great job on all your work.

    Louie the lightbulb.