1. Electricity Generation From Lignite Mark K
Electricity Generation From Lignite Mark K. Thompson Basin Electric Power Cooperative Leland Olds Station
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2. Over 2.5 million people served with ND lignite-based electricity
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3. Every 4 megawatts requires approximately 3 jobs
Economic Impact
Every 4 megawatts requires approximately 3 jobs
So while we produce power for many states, the jobs are in North Dakota.
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4. Lignite A low-cost abundant resource for generation of electricity
North Dakota Lignite plants such as Milton R Young Station, Antelope Valley Station and Coal Creek Station have consistently ranked among the lowest cost producers in the United States. The abundance of lignite and the efficiency of the mining operations makes this possible
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5. Agenda Basics of generating electricity
Commercial generating technologies
Lignite as a fuel source
Controlling emissions
Generating electricity
Summary
Basics of generating electricity apply to all commercial generating technologies
A brief review of the technologies used by the industry for generation of electricity
A more detailed look at lignite as the fuel source for generating electricity
The emissions controls utilized on generating plants in North Dakota that keeps North Dakota among the cleanest air in the nation.
The process of generating the electricity
A wrap up and the main points to learn from this presentation.
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6. Magnetic Field Around Bar Magnet
Lines of force
(Flux) N S
Magnetism is the fundamental science behind the production of electricity. Even though the lines of force from a magnet are invisible, iron filings can be used to demonstrate to students that these lines of force are present.
Magnet
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7. Producing Electricity From Magnetism
Coil
In further demonstration of the effect of the lines of force in a magnet, a sensitive galvanometer can show that electricity is generator when a magnet is moved back and forth through a coil of wire. The movement of a magnet past a coil of wire is the basic concept behind the science of generation of electricity. Large generators use this on a much large scale.
Meter
(Galvanometer)
Magnet
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8. Basics of How Electricity is Made
Developing the concept of moving the magnet through a coil of wire into the next level of sophistication is demonstrated here. Rotating the magnet makes it possible to have continuous generation of electricity to keep the bulb lit. A source of energy must be supplied to rotate the magnet.
This is a good time to do the demonstration of the bicycle. In that case a person is supplying the energy to rotate the magnet and the light bulbs that light up is the evidence of their work. It also is obvious to the rider that it takes more and more energy to light more bulbs. In other words as electricity is generated there is resistance to rotation of the magnet that must be overcome to generate electricity.
Producing
Electricity!
A source
of energy
such as
lignite
To push
blades
on a
shaft
Which spins
a magnet
inside a
coil of wire
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9. Portable Generators? One light bulb lit Eight light bulbs lit 6/17/089

10. How Many Bicyclists?
To produce as much electricity as North Dakota’s seven power plants... And they would need to keep pedaling for 24 hours a day / seven days a week
1. 10, ,000
3. 3,000, More than 3 M
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11. How Many Bicyclists?
It would take 8.9 million people on bicycles to produce as much electricity as North Dakota’s seven power plants And they would need to keep pedaling for 24 hours a day / seven days a week!
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12. Other Primary Sources of Energy For Generation of Electricity
Wind - windmill or wind turbine
Water - water wheel or water turbine
Diesel - diesel engine
Natural gas - gas turbine
Other primary source of energy for electrical generation utilize the same basic concept.
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13. Basics of How Electricity is Made
This shows a windmill providing the energy to rotate the magnet
A source
of energy
such as
wind
To push
blades
on a
shaft
Which spins
a magnet
inside a
coil of wire
Producing
Electricity!
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14. Renewable, clean but intermittent
Wind Generators
Large power generation wind turbines
Renewable, clean but intermittent
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15. Basin Electric’s Wind Facilities
Minot
Wilton
Edgeley
Groton
450 MW Nameplate capacity
Highmore
Pipestone
Chamberlain
Rosebud
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16. Basics of How Electricity is Made
The old fashioned water wheel could be a source of energy to turn a generator
A source
of energy
such as
water
To turn
blades
on a
shaft
Which spins
a magnet
inside a
coil of wire
Producing
Electricity!
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17. Water-Hydro Generation
Large water turbines such as those at Garrison Dam turn generators for production of “hydro” power
Renewable, clean and reliable….but expensive and hard to build today
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18. Basics of How Electricity is Made
A diesel or gasoline engine can be used to turn the shaft of a generator
A source
of energy
such as
a diesel engine
To turn
a shaft
Which spins
a magnet
inside a
coil of wire
Producing
Electricity!
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19. Used for short term peaking – expensive
Diesel Generator
Large package Diesel generators come in many sizes for backup generators and peaking power applications
Used for short term peaking – expensive
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20. Basics of How Electricity is Made
Another type of engine the is used to drive a generator is a gas turbine. These often use natural gas as a fuel. They are similar to an engine on a jet airplane.
A source
of energy
such as
burning gas
To turn
blades on
a shaft
Which spins
a magnet
inside a
coil of wire
Producing
Electricity!
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21. Natural gas is cleaner but expensive
Gas Turbine
This is an outside view of a gas turbine generating plant. Six gas turbines sit inside a building near each of the stacks in the picture. Total generation at this site is about 500MW.
Natural gas is cleaner but expensive
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22. Affordable, reliable, increasingly clean
Most Common Commercial Technology for Large-Scale Electrical Generation
Affordable, reliable, increasingly clean
The most common method of generating electricity is using steam turbines with steam supplied from a coal fired boiler. This is the Coyote Station, one of the large lignite fired power plants in North Dakota.
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23. Exploring lignite as a fuel source with steam turbine generators
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24. Lignite is One-Third Water
COAL
H O 2
Lignite in North Dakota is about 1/3 water.
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25. Conversion Efficiency is 35 Percentx =
35%
Converting a high moisture fuel like lignite to electricity utilizes about 35% of the total heat in the coal. By comparison many internal combustion engines are less than 30% efficient.
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26. Improving Mother Nature
Parameters of ND Lignite as found in nature
Heating value 6,000 to 7,000 BTU / Lb (other coals 8,000 to 12,000 BTU / Lb)
Ash content in ND lignite 6% to 12% as burned
Sodium content high in many areas – contributes to challenges
Deposits in boiler
Other mineral constituents
Montana and Wyoming sub bituminous coal is generally in the 8,000 to 9500 Btu/lb range. Eastern bituminous coal is in the 10,000 to 12,000 range. Lignite competes mainly with sub bituminous.
Other coals often have less ash percentage and also less total ash because of their higher heating value.
Sodium and other mineral constituents in the lignite ash make it a more challenging fuel to burn
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27. Coal-Drying Project Coal Creek Station
Low temperature waste heat is being used to reduce moisture in lignite
Increases plant efficiency and reduces emissions
About a third of you will be touring Great River Energy’s Coal Creek Station near Washburn tomorrow. I want to give you a little preview of what you’ll hear more about…the use of waste heat from the boiler to reduce the moisture in lignite.
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28. How is Lignite Converted Into Electricity?
Now move the discussion to how lignite is converted to electricity and how the characteristics of lignite affect that process.
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29. How Electricity is Made Using a Steam Turbine
Emissions Control
Steam
Equipment
Turbine
Generator
Steam
Pulverized
Coal
Most lignite fired power stations pulverize the lignite into a fine powder and use hot air to carry the pulverized lignite to the burners in the boiler. The heat from burning the lignite generates steam which is use to drive a steam turbine which turns the generator.
Water
Condenser
Hot Air
Boiler
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30. Lignite Receiving & Stockpile
Lignite is received either by train or directly from the mine by truck and is conveyed to the stockpile and into the plant. On the stockpile huge dozers are used to level and compact the lignite for storage until it is used.
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31. Lignite conveyed into plant
The conveyors that move the lignite are belts of rubber that ride on trough rollers. The larger conveyors can carry about 2,500 tons per hour and are about 5 feet wide. Smaller conveyors are used to distribute coal to the locations where it is prepared for burning.
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32. Pulverizers prepare the lignite
The coal pulverizers crush the coal to a fine powder about like face powder. They are driven by large motors. Large Fans provide hot air to dry the coal and carry it to the boiler.
Pulverizers prepare the lignite
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33. Lignite-Fired Boiler Bunker Burners Coal Feeder Lift Line Pulverizer
The hot air carries the powdered lignite through pipes to the boiler and into the burners. Each boiler contains multiple burners to distribute the lignite for proper combustion and so the heat from burning the lignite gets transferred to the water for generating steam.
Feeder
Lift
Line
Pulverizer
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34. Photo of oil during startup
When the lignite burns in the furnace the temperature is 2500 to 3000 degrees Fahrenheit.
Photo of pulverized coal
Photo of oil
during startup
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35. 2,400 PSI Steam Pressure 2,400 Pounds 2,400 pounds per square inch
Heat is transferred to the water in the boiler to make the steam. The steam in many boilers is around 2400 pounds per square inch. That is equivalent to a large draft horse standing with all of it’s weight on one square inch.
2,400 pounds
per square inch
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37. Steam turbine generator
The Steam Turbine/ Generators are among the large equipment in a plant. This shows a turbine generator at on of the local plants. The steam enters the turbine through the pipes in the front of the picture. The generator is at the far end.
Steam turbine generator
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38. Generator during assembly
This is an example of the inside of a generator.
Generator during assembly
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39. This is a picture of the rotating part or rotor of a generator
This is a picture of the rotating part or rotor of a generator. This rotor is coupled to the turbine rotor when it is installed in the generator. This is like the rotating magnet in our simple illustration of the generation of electricity.
Generator stator work
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40. Modern control room with computerized controls
This picture is the open end of a generator during disassembly.
Modern control room with computerized controls
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41. Plant Transformers Auxiliary transformers for plant power
Once the rotor has been remove from the generator this is what the interior of the generator looks like. The red materials you see at the front of the picture are the generator windings. That is where the electricity is generated.
Plant Transformers
Auxiliary transformers for plant power
Step-up transformers for sending power out
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42. Power Plant Substation
After the power is stepped up in voltage at the startup transformer it goes to the substation. At the substation switches and breakers are operated to put the electricity on the transmission lines where it is needed. You’ll hear more about transmission on Thursday morning from Sandi Tabor, the director of the North Dakota Transmission Authority.
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43. Lignite boiler emissions in North Dakota are controlled with up-to-date technology
All North Dakota plants have technologies to control emissions.
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44. Cutaway view of precipitator
The baghouse has large bags similar to vacuum bags that remove dust from the boiler exhaust gasses. For the two-thirds of the group going to Antelope Valley Station, you may see a real bag during the tour.
Cutaway view of precipitator
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45. The spray dryer with a baghouse is a technology used to remove sulfer dioxide and flyash.
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47. ND Power Plants Fitted With Scrubbers
Percent of Scrubbed Capacity
100
98% 90 80 70
73% 60 50 40
A much higher percentage of ND plants have scrubber capacity for removing sulfur dioxide than other parts of the country and in the coming three years this percentage will increase. Scrubbers are being built or enlarged at the Leland Olds Station and the Young Station right now. 30 20 10
North Dakota (now)
North Dakota (2012)
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48. Clean Air States
North Dakota has always been a clean air state under EPA guidelines. Currently, it is joined by 10 other states. The most recent one is Maine that joined in the last couple of years. The investments being made at the existing North Dakota plants, including the coal drying at Coal Creek Station and the expanded scrubber capacity at Leland Olds Station and Young Station will ensure that North Dakota remains a clean air state as federal air quality rules continue to become more stringent.
Source: EPA, May 1, 2010
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49. Sources of Electricity from Lignite
3887 MW Total
1200
1,100
1000
900
800
673
650
MW Capacity
600
420
400
Here’s a chart that show the capacity of the various power plants. This chart is conservative considering that most plants have been retrofitted over the years with better control equipment and improved turbines which actually can improve the efficiency and thus the number of megawatts being produced.
200
100 44
Lewis &
Heskett
Coyote
Leland
Young
Antelope
Coal
Clark
Olds
Valley
Creek
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50. A Rule of Thumb North Dakota Capacity Requirement = 2 KW per person
650,000 persons X 2 KW per person
Obviously, North Dakota produces a lot more electricity than it consumes. We are a net exporter of electricity – from our lignite plants, our hydro dam and wind farms.
= 1,300,000 KW or 1,300 MW
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51. Estimated Demand Bismarck / Mandan - 190 MW Fargo / Moorhead - 350 MW
St. Cloud MW
Minneapolis / St. Paul Area - ???? MW
MW ,000 MW
3. 2,500 MW ,000 MW
You can see that much of our power produced in coal country heads east on large transmission lines to serve major loads.
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52. Estimated Demand Minneapolis / St. Paul Area - 6,000 MW
You can see that much of our power produced in coal country heads east on large transmission lines to serve major loads.
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53. About one-third of MN’s electricity comes from ND and the percentage is higher in rural MN
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54. Summary
Lignite is a low-cost, abundant resource for the generation of electricity that is beneficial for the region
Lignite is a secure and reliable source of energy
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