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How is Electricity Generated?
See how electricity is generated by taking a virtual tour of a power plant.
Converting Coal to Electricity
Coal contains the energy we need to power our homes, our businesses and our lives. Here's how our power plants transform that energy into the affordable, reliable electricity you count on to power your life.
Large conveyors transport the coal into the plant, where pulverizers crush it into a fine powder. Huge fans draw air into the plant and through a heat exchanger, which transfers heat from outgoing exhaust to the incoming air. Half of this heated air is used to dry the coal and blow it into a boiler. The rest of the incoming air goes directly into the boiler, where the pulverized coal ignites and reaches temperatures of up to 3,000 degrees Fahrenheit.
The hot gases in the boiler turn water into steam, which becomes super-heated. The steam enters a high-pressure turbine, causing its blades to rotate. This rotation turns a shaft which is connected to the generator.
The generator consists of a rotor and a stator. The rotor spins inside the stator at 3,600 revolutions per minute, creating a flow of electricity that exits the generator at 22,000 volts.
The electricity flows to a step-up generator, where the voltage is increased to 354,000 volts. The power is then sent out over a network of transmission lines to homes, farms and businesses.
The exhaust air created by the process of turning coal into electricity passes through a scrubber, then through a filter process that removes 99.9 percent of ash and other particulates. After passing through the environmental system, the exhaust air is sent up the stack.
On a cold day, you may see a white plume coming from the power plant's stack. That plume is just condensed water vapor. On hot days, the water vapor doesn't condense, so you won't see a plume, even though the plant is working to bring you the power you need.
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