Burns Fuels

• Coal is the primary fuel source.
• Natural gas and pre-consumer plastic and paper products also contribute to the fuel mix.
• Coal arrives by railcar. It is transported into the plant through an enclosed conveyor system.
• It is pulverized into powder and mixed with air, then piped inside boilers where it is burned.
• Miles of tubing inside the boilers circulate water which absorbs heat and is converted into steam.

Boilers produce steam

• Nine boilers produce high-pressure steam for six turbine generators.
• The two largest boilers produce 400,000 pounds of steam per hour at 950 degreesFahrenheit and at 1,250 pounds per square-inch pressure.
• By comparison, water in a residential water heater is warmed to approximately 125 degrees Fahrenheit at 85 to 95 pounds per square-inch pressure.

Steam spins the turbines

• The high-pressure steam passes through a turbine.
• A turbine consists of rows of blades that radiate from a center shaft similar to spokes on a bicycle wheel.

Turbines drive the generator

• The shaft rotates within the generator.
• The generator has two parts: stationary coils of copper wire (stator) and a rotating magnet (rotor) within the stationary stator coils.
• As the magnetic field of the rotor whirls past the stationary copper coils, electricity is generated at high voltage.

Steam is cooled by a condenser

• After steam flows through the turbine, it passes through a condenser where it is cooled and changed back into water.
• The condensed water then returns to the boiler to be converted into steam again.
• Water used to condense the steam is pumped into condenser tubes from Lake Monona and then returned to the lake after it is used.
• Lake water never comes into direct contact with the steam produced in the boilers.

Electricity from power plant to you

• Electricity leaves the generator at 13,800 volts.
• A transformer increases it to 69,000 volts or higher.
• For commercial, residential and industrial use, electricity travels along transmission wires to a substation where voltages are decreased to either 4,160 or 13,800 volts.
• Overhead and underground distribution lines carry the electricity to smaller transformers for reduction to the 120/240 volts used for household electric service.