Electrical Power Generation

1. Electrical Power Generation What’s on the other end of a power line? A Special Report by Mr. Meador & Ms. Shaw, Bartlesville High School Tour Pictures from 1995 2008 Revision www.bhsphysics.org

2. Darkness Join us on a trip to a typical electric power plant, where we hope to shed some light on the subject of electric power generation.

3. To Oologah Bartlesville Oologah Tulsa Oklahoma City We hopped in a car and drove 40 miles from Bartlesville to Oologah, Oklahoma. Oologah is the birthplace of Will Rogers, and is also the home of the Public Service Company of Oklahoma’s Northeast Power Plant.

4. Exterior View of Generators As you approach the plant, you can see two natural-gas-fired generators to the left of the smokestack. To the right are two coal-fired generators.

5. Entry Phone At the plant entrance, Mr. Meador calls the plant superintendent, asking permission to enter.

6. Hard Hats Plant superintendent Gary Briggs outfitted us with hard hats so that we could tour the 1.5 billion watt facility.

7. Coal Car Dumper The first stop is the coal car dumper, where 110 train cars a day bring in low-sulfur coal from Wyoming. The cars are turned upside-down and the coal is carried by a conveyor belt to a large storage yard.

8. Lab Samples of the incoming coal are sent to this on-site lab and analyzed for impurities and energy content. Wyoming coal has less energy content than the native Oklahoma coal; however, Oklahoma coal has more sulfur, which contributes to acid rain.

9. Coal Storage Yard Back in the coal storage yard, a 60-day reserve supply is maintained. In 1994, this entire reserve was used up, because of train delays due to floods. PSO responded by buying electrical power from other utilities. Power plants across the United States are interconnected, so that they can buy and sell power between each other.

10. Coal Compaction The coal in the storage yard is compacted, to reduce dust and keep air away from the coal. Otherwise, spontaneous combustion could occur.

11. Coal Scooper Coal is fed into the plant by shoveling it over to this giant machine, which scoops is up onto a conveyor belt.

12. Coal Conveyor The conveyor belt carries the coal up to the top of the plant.

13. Boiler Exterior There the coal is crushed to the consistency of talcum powder and blown by air into a fifty foot tall boiler.

14. Boiler Fire The purpose of any power plant boiler is to heat water into steam. Here we see Briggs by one of the plant's coal boilers. It burns coal to heat water to 1000 degree Fahrenheit steam. Not all of the coal entering the boiler can be burned. The unburned heavy ash falls to the bottom of the boiler and is removed and used for road base and cinder blocks.

15. Smokestack The lighter fly ash goes up the smokestack, where it is given a negative charge and drawn off by an electrostatic precipitator. This material is used in concrete and cement.

16. Turbine (intact) The steam from the boiler is sent to the power plant's turbine.

17. Turbine (dismantled) One of the plant's turbine/generator systems was being dismantled for maintenance, so we were able to inspect some of its parts.

18. Steam from the boiler pushes against the fan blades of the turbine. This turns a shaft leading into the generator. Magnets on the end of the shaft spin inside a coil of wire to create the electricity. Plant Diagram Adapted from a diagram by the Tennessee Valley Authority

19. Turbine Blades Here are the fan blades in the turbine which are rotated by the steam.

20. Coil Magnets attached to one end of the spinning turbine shaft rotate inside this giant coil of wire. The spinning magnetic field pushes the electrons in the wire, creating the electrical current.

21. Turbine piping The generators must be cooled or they will crack. Cooling water from Lake Oologah is pumped through these tubes in the 10-inch thick generator walls. 200,000 gallons of water flow through these tubes each minute.

22. Cooling Towers To prevent environmental damage, this water must be cooled before it is returned to the lake. It is pumped to cooling towers, where some of the water evaporates, which cools the remaining water. The clouds of steam we see rising above the power plant are this evaporated water.

23. Control Room Here we see the control room, from which the entire plant is monitored. To protect the power plant's equipment, start-ups and shut-downs must be done carefully and slowly. This power plant actually cannot start up on its own, but must borrow power from another plant to pre-heat its generator.

24. Battery Room If the power plants needs to shut down, the large batteries shown here provide the power for a controlled stop.

25. Transformers The plant’s generator produces electricity at 22,000 volts.

26. Step-down Transformer One large transformer outside the plant steps the voltage down to 5,000 volts. This power is used to run the plant’s fans as well as the electromagnets inside the generator.

27. Step-up Transformer A second transformer outside the plant connects the generator to the cross-country power lines. It steps the voltage up, from 22,000 volts to 345,000 volts. This high voltage lowers the current in the cross-country lines, which reduces energy loss.

28. Switchyard The high voltage electricity is sent to the switchyard, where it is routed to various cities.

29. Outbound Line Having completed our tour, we leave the plant and trace an outbound line which leads to a city's substation. To minimize weight, electrical power lines are not covered with insulation; they are bare wire.

30. Substation A cross-country power line feeds into this substation near Tri-County Tech in Bartlesville. The substation has giant circuit breakers as well as step-down transformers which lower the voltage to 13,800 volts for city-wide distribution.

31. City Line Here is a city power line. The top wire carries no current, because it tends to be struck by lightning. The three wires below it carry higher voltage electricity across town. Three smaller wires below those carry lower voltage electricity to nearby neighborhoods. The lowest wires on the line are for phone and cable television service.

32. Pole Transformer Here we see a pole-mounted neighborhood transformer. It lowers the 13,800 volts from the city power line to 120 volts for use in homes and businesses.

33. Ground Transformer Here Ms. Shaw inspects another type of transformer, used in neighborhoods with below-ground wiring.

34. House Meter And at last we reach a home or business, where the amount of electrical energy being used is measured by a meter.

35. Pole Painting And that concludes our special report on electrical power generation. Now you know what is on the other end of a power line.

36. Electrical Power Generation Special thanks to the Public Service Company of Oklahoma and Gary Briggs Power Plant Diagram adapted from original art by the Tennessee Valley Authority www.bhsphysics.org