Electricity Generation From Lignite John Weeda Director ND Plant Operations June 18, 2013

Reliable, low-cost electricity Great River Energy –2 nd largest utility in MN –28 member cooperatives 850+ employees (MN and ND) 2,751 MW owned generation 469 MW wind 4,500+ miles transmission lines $868.5 million 2011 operating revenue $3.35 billion total assets Capital markets

Our triple bottom line… Affordable rates Reliable electric service Environmental stewardship EnvironmentEnvironment ReliabilityReliability RatesRates

GRE resource portfolio

Types of Generation Baseload power is available for 24-7 demand –High-capacity generating plants –Plants cost less to operate when at full efficiency Peaking power is available when demand is highest –Higher cost to operate, but quick start-up to react to demand changes Intermittent power is available when supply allows –Cannot be relied upon to react to level of demand

GRE Power Plants

Lignite A low-cost abundant resource for generation of electricity

Over 2.0 million U.S. customers served – 850,000 Canadian customers Fort Union Lignite

Economic Impact Every 4 megawatts of Lignite-based Electric Generation requires about 3 jobs

Basics of generating electricity Commercial generating technologies Lignite as a fuel source Controlling emissions Generating electricity Summary Agenda

N S Lines of force (Flux) Magnet Magnetic Field Around Bar Magnet

Coil Magnet Meter (Galvanometer) Producing Electricity From Magnetism

To push blades on a shaft Which spins a magnet inside a coil of wire Producing Electricity! A source of energy such as lignite Basics of How Electricity is Made

Battle of the Bulbs

Electricity Savings The same amount of electricity used to light up one incandescent light bulb will light up how many LED bulbs? 1.2 LED bulbs 2.5 LED bulbs 3.10 LED bulbs 4.20 LED bulbs 5.50 LED bulbs

Electricity Savings The same amount of electricity used to light up one incandescent light bulb will light up how many LED bulbs? 1.2 LED bulbs 2.5 LED bulbs 3.10 LED bulbs 4.20 LED bulbs 5.50 LED bulbs

Primary Sources of Energy for Generation of Electricity Thermal generation - coal fired Nuclear generation - reactors Water - water wheel or water turbine Wind Generators- wind turbines Diesel - diesel engine Natural gas - gas turbine

Wind Generators Renewable, clean but intermittent

Basics of How Electricity is Made To push blades on a shaft Which spins a magnet inside a coil of wire Producing Electricity! A source of energy such as wind

Basin Electrics Wind Facilities Minot Edgeley Hyde County Chamberlain Pipestone Wilton Hancock Crosswinds PW 1 PWSD1 Day County Superior Lakota 713 MW Baldwin Oaklane SMSC Wind SD Wind Partners

Water-Hydro Generation Renewable, clean and reliable….but expensive and hard to build today

To turn blades on a shaft Which spins a magnet inside a coil of wire Producing Electricity! A source of energy such as water Basics of How Electricity is Made

Wind and Water Renewable but intermittent Load characteristics impact base- load units – follow the wind and water High water or wind generation – base-load units drop off

Diesel Generator Used for short term peaking – expensive

To turn a shaft Which spins a magnet inside a coil of wire Producing Electricity! A source of energy such as a diesel engine Basics of How Electricity is Made

Gas Turbine Natural gas is cleaner but pricing is volatile

To turn blades on a shaft Which spins a magnet inside a coil of wire Producing Electricity! A source of energy such as burning gas Basics of How Electricity is Made

Exploring lignite as a fuel source with steam turbine generators

Most Common Commercial Technology for Large-Scale Electrical Generation Affordable, reliable, increasingly clean

How is Lignite Converted into Electricity?

Emissions Control Equipment Hot Air Boiler Water Condenser Steam Turbine Steam Generator Pulverized Coal How Electricity is Made Using a Steam Turbine

Lignite Receiving & Stockpile

Lignite conveyed into plant

Pulverizers prepare the lignite

Bunker Burners Coal Feeder Pulverizer Lift Line Lignite-Fired Boiler

Photo of pulverized coal Photo of oil during startup

2,400 Pounds 2,400 pounds per square inch 2,400 PSI Steam Pressure

Steam turbine generator

Generator during assembly

Generator stator work

Modern control room with computer equipment

Plant Transformers A.Auxiliary transformers for plant power S.Step-Up transformers for sending power out

Power Plant Substation

Lignite has some challenging characteristics

x = 35% Conversion Efficiency is lower due to high moisture

Other Challenging Characteristics 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

DryFine Can Improve Lignite Coal Creek Station –Low temperature waste heat is being used to reduce moisture in lignite –System segregates unwanted portion of fuel –Increases plant efficiency and reduces emissions

Lignite boiler emissions in North Dakota are controlled with up-to-date technology

Cutaway view of precipitator

100 ND Power Plants Fitted with Scrubbers More than $800 million has been invested by Basin Electric and Minnkota to retrofit Young 1 and LOS 1 & 2 with scrubbers – now 98% of ND generation is equipped with scrubbers

Clean Air States Source: EPA, May 1, 2010

MW Total MW Capacity 1, Lewis & Clark Heskett Coyote Leland Olds YoungAntelope Valley Coal Creek Sources of Electricity from Lignite

Heat & Power Efficiency Improvements Coal Creek Station sends a mix of primary & waste steam to Blue Flint Ethanol Plant is low-cost producer of ethanol in the United States (no need to build or maintain a boiler) Spiritwood Station is a combined heat & power plant located near Jamestown, ND Will generate electricity for homes & businesses & steam for Cargill Malt When fully utilized, plant will be 66 percent efficient Compared to 30 to 35 percent efficient for most coal-based power plants

Capacity Requirement = 2 KW per person 650,000 persons X 2 KW per person = 1,300,000 KW or 1,300 MW North Dakota A Rule of Thumb

Bismarck / Mandan -190 MW Fargo / Moorhead -350 MW St. Cloud -335 MW Minneapolis / St. Paul Area -???? MW MW2. 1,000 MW 3. 3,500 MW4. 6,000 MW Estimated Demand

Bismarck / Mandan -190 MW Fargo / Moorhead -350 MW St. Cloud -335 MW Minneapolis / St. Paul Area -3. 3,500 MW Estimated Demand

About one-fifth of MNs electricity comes from ND -- the percentage is much higher in rural MN

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 Lignite-based power plants are in compliance with all federal ambient air quality standards

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