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How IPL Brings Electricity to Your Home or Business

This simplified diagram shows the basic operation of a typical large coal-based electric power plant and explains the different functions of a plant's major components. It also illustrates how electricity is made and delivered to consumers and shows the many control technologies in place to reduce emissions to air, land and water, and thereby help protect the environment.   Printer-friendly version.

Elect to home WEB 3

Coal-based Electricity Production (Red)

1. Coal
Coal is the most abundant and cost-effective domestic fuel for generating electricity. IPL consumes more than 7 million tons of Indiana coal annually. The coal is mined in southwestern Indiana and transported by truck and rail to our power plants.

2. Primary Air/Fan Pulverizer
A set of devices used to prepare coal for burning by grinding it into a fine powder, then drying and mixing it with air for efficient combustion.

3. Burner
A nozzle device, generally located in the lower boiler walls, which introduces the pulverized coal into the boiler and mixes it with the correct amount of additional air to burn the fuel efficiently and reduce nitrogen oxides (NOx) and carbon monoxide emissions.

4. Steam Generator (Boiler)
A large vessel that contains an assembly of tubes in which water is heated into steam that is used to drive a turbine.

5. Turbine
A device consisting of fan-type blades attached to a shaft that is spun by directing high temperature and pressure steam against the blades, converting the kinetic energy of the steam into mechanical energy.

6. Condenser
A device that converts the steam from the turbine back into water, to be recirculated to the boiler, where it is heated and used again.

7. Cooling Water
Outside water used to condense the steam passing through the condenser.

8. Cooling Tower
A device that cools heated circulating water from the condenser. Outdoor air flows through a spray of the heated water and cools it by evaporation. The cooled water is then released to a nearby river at a temperature that is safe for aquatic life.

9. Generator
A machine that transforms the mechanical energy of the turbine into electric energy.

10. Transformers
Electromagnetic devices that increase or decrease the output voltage of the generator while reducing the current (amperage) to make the transmission of electricity more efficient. There are different types of transformers.

11. Electricity
Electricity is transformed down to voltages suitable for industrial, commercial or home use.

Environmental Controls (Green)

1. Bottom Ash
A coal-combustion byproduct that collects on the walls of the boiler, eventually falling to the bottom where it is collected. Bottom ash is a ceramic-like material that can be used to make asphalt, aggregate, insulation and blast-cleaning grit.

2. NOx Controls
Devices like low NOx burners and selective catalytic reduction systems that are used to lessen NOx emissions.

3. Electrostatic Precipitator
An environmental device used to remove the fly ash from the boiler exhaust (flue) gas.

4. Fly Ash
A light gray or tan powder that is the largest byproduct of coal combustion. Fly ash mixes with and is carried out of the boiler by the hot exhaust (flue) gases. It is collected and has uses similar to those for bottom ash.

5. Scrubber
An environmental device used to remove sulfur dioxide (SO2) from the boiler exhaust (flue) gas.

6. Stack
A structure used to exhaust and disperse the hot flue gases from the boiler.

7. Emissions Reduction
Since 1970, electric utilities nationwide have reduced air emission significantly while increasing electricity production. Although coal use has tripled since 1970, and coal-fired electricity now accounts for 50 percent of the nation’s energy, emission have been reduced.