Iowa State University Power Plant

Iowa State University Utility Enterprise Operates as a rate-based enterprise Operates as a rate-based enterprise Charges university entities for the utilities they consume Charges university entities for the utilities they consume Employs 78 people Employs 78 people Operates two facilities on main campus and two satellite facilities Operates two facilities on main campus and two satellite facilities Has the capability to provide all the energy needs of the university Has the capability to provide all the energy needs of the university

Iowa State University Utility Enterprise Overall budget of $35.7 million Overall budget of $35.7 million Coal - $13.7 millionCoal - $13.7 million Limestone - $412,000Limestone - $412,000 Ash disposal - $780,000Ash disposal - $780,000 Purchased electricity - $2.05 millionPurchased electricity - $2.05 million Last year the cost of these items averaged $45,000 every dayLast year the cost of these items averaged $45,000 every day

Power Plant 6 boilers – total capacity of 900,000 lbs of steam per hour – peak load of 488,000 lbs/hr 6 boilers – total capacity of 900,000 lbs of steam per hour – peak load of 488,000 lbs/hr 4 turbine-generators – total capacity of 46 megawatts – peak load of 34.1 megawatts 4 turbine-generators – total capacity of 46 megawatts – peak load of 34.1 megawatts 5 chillers – total capacity of 21,000 tons of cooling – peak load of 15,169 tons 5 chillers – total capacity of 21,000 tons of cooling – peak load of 15,169 tons 4 air compressors – total capacity of 4,000 cubic feet per minute – peak of 1800 cfm 4 air compressors – total capacity of 4,000 cubic feet per minute – peak of 1800 cfm 1 water plant – capacity of 1,000,000 gallons per day – peak requirements of 1.3 million gpd 1 water plant – capacity of 1,000,000 gallons per day – peak requirements of 1.3 million gpd Replacement value of $282 million Replacement value of $282 million

FY08 Plant Production Steam produced – 2,623,141,000 lbs Steam produced – 2,623,141,000 lbs Steam to campus – 1,095,721,000 lbs Steam to campus – 1,095,721,000 lbs Chilled water – 33,343,000 ton-hrs Chilled water – 33,343,000 ton-hrs Electricity consumed – 200,886,000 kwh Electricity consumed – 200,886,000 kwh Generated electricity – 151,831,000 kwhGenerated electricity – 151,831,000 kwh Purchased electricity – 45,956,000 kwhPurchased electricity – 45,956,000 kwh Coal burned – 154,463 tons Coal burned – 154,463 tons Limestone used – 14,749 tons Limestone used – 14,749 tons Ash produced – 28,178 tons Ash produced – 28,178 tons

Other Utility Consumption Natural Gas used – 24,584,000 cubic feet Natural Gas used – 24,584,000 cubic feet Domestic water used – 313,524,000 gallons Domestic water used – 313,524,000 gallons Sewage generated – 202,684,000 gallons Sewage generated – 202,684,000 gallons

Mechanical Distribution Systems Steam tunnels – 4.5 miles Steam tunnels – 4.5 miles Direct buried steam – 2.6 miles Direct buried steam – 2.6 miles Chilled water – 5.3 miles Chilled water – 5.3 miles Domestic water – 8.3 miles Domestic water – 8.3 miles Natural gas – 4.5 miles Natural gas – 4.5 miles Sanitary sewer – 10.3 miles Sanitary sewer – 10.3 miles Storm sewer – 25.2 miles Storm sewer – 25.2 miles Compressed air – 3.5 miles Compressed air – 3.5 miles Replacement value of $113 million Replacement value of $113 million

Electrical Distribution Systems High voltage electrical cables – 16.7 miles High voltage electrical cables – 16.7 miles Electrical transformers – 515 Electrical transformers – 515 Electrical substations – 7 Electrical substations – 7 Telecommunications cables – 90 miles Telecommunications cables – 90 miles Street, sidewalk and parking lot lights – 1900 Street, sidewalk and parking lot lights – 1900 Traffic lights – 7 Traffic lights – 7 Replacement value - $53 million Replacement value - $53 million

Cogeneration Sometimes called combined heat and power or CHP Sometimes called combined heat and power or CHP Defined as using a single fuel source to simultaneously produce thermal energy and electrical power Defined as using a single fuel source to simultaneously produce thermal energy and electrical power Thermal efficiencies of more than 70% are attainable as compared to typical utility plant efficiencies of 35-42% Thermal efficiencies of more than 70% are attainable as compared to typical utility plant efficiencies of 35-42% Iowa State started cogenerating in 1891 and typically averages 50-55% thermal efficiency Iowa State started cogenerating in 1891 and typically averages 50-55% thermal efficiency

Cogeneration

ISU Energy Source Currently burning 100% coal Currently burning 100% coal Coal comes from southern Illinois and western KentuckyCoal comes from southern Illinois and western Kentucky Coal is barged to Muscatine, Iowa and loaded onto trucksCoal is barged to Muscatine, Iowa and loaded onto trucks Trucks deliver coal to ISU and haul grain back to the Mississippi to be loaded onto bargesTrucks deliver coal to ISU and haul grain back to the Mississippi to be loaded onto barges Approximately 6200 trucks per year, 25 per dayApproximately 6200 trucks per year, 25 per day

ISU Energy Source Coal is blended to our specifications in Muscatine at the dock facility Coal is blended to our specifications in Muscatine at the dock facility Coal Quality Coal Quality Eastern Bituminous coalEastern Bituminous coal 11,800 BTU/lb11,800 BTU/lb 2.4% sulfur (medium sulfur)2.4% sulfur (medium sulfur) 8.5% ash8.5% ash 10.5% moisture10.5% moisture

Emissions Limits ISU Power Plant had no emissions limits prior to the 1970s ISU Power Plant had no emissions limits prior to the 1970s Clean Air Act of 1970 required improvements in emissions performance at facilities across the country Clean Air Act of 1970 required improvements in emissions performance at facilities across the country Emission limits have become more stringent over time Emission limits have become more stringent over time New plant equipment typically had to comply with emissions limits that existed at the time of construction New plant equipment typically had to comply with emissions limits that existed at the time of construction Todays proposed emissions regulations are typically retroactive to existing equipment Todays proposed emissions regulations are typically retroactive to existing equipment Plants must retrofit pollution control equipment, change to different cleaner fuels, or replace equipment with new that meets new regulationsPlants must retrofit pollution control equipment, change to different cleaner fuels, or replace equipment with new that meets new regulations Implementation of new regulations are now often delayed due to litigation by environmental groupsImplementation of new regulations are now often delayed due to litigation by environmental groups

Emissions Limits PollutantStoker BoilersCFB Boilers Sulfur Dioxide5.0 lb/mmBTU 1.0 lb/mmBTU (30 day average) 1.42 lb/mmBTU (3 hr average) 90% removal Nitrogen Oxidesnone 0.40 lb/mmBTU (30 day average) 0.40 lb/mmBTU (3 hr average) Carbon Monoxidenone200 ppm Particulate lb/mmBTU 40% Opacity lb/mmBTU 10% Opacity Fluoridenone0.039 lb/mmBTU Leadnone lb/mmBTU Berylliumnone lb/mmBTU

Emissions Controls ISU retrofitted pollution control equipment for particulate on all boilers through the late 1970s ISU retrofitted pollution control equipment for particulate on all boilers through the late 1970s Switched from high sulfur Iowa coal to washed Iowa coal and eastern coals Switched from high sulfur Iowa coal to washed Iowa coal and eastern coals Installed new circulating fluidized bed boilers in 1988 Installed new circulating fluidized bed boilers in 1988

Mechanical Dust Collectors Retrofitted to existing boilers in the mid- 1970s Retrofitted to existing boilers in the mid- 1970s Collect particulate by centrifugal force Collect particulate by centrifugal force Efficiency drops as ash particles get smaller Efficiency drops as ash particles get smaller Collection efficiency is 90% at best Collection efficiency is 90% at best Boiler 5 is fitted with a mechanical dust collector only Boiler 5 is fitted with a mechanical dust collector only Opacity when Boiler 5 is operating is typically 15-20% Opacity when Boiler 5 is operating is typically 15-20% Emissions rate is 0.35 lb/mmBTU Emissions rate is 0.35 lb/mmBTU

Mechanical Dust Collector

Electrostatic Precipitator Retrofitted to Boilers 3 & 4 in the late 1970s Retrofitted to Boilers 3 & 4 in the late 1970s Collect particulate by electric charge Collect particulate by electric charge Collection efficiency is about 97% Collection efficiency is about 97% Boilers 3 & 4 are fitted with a mechanical dust collector and an electrostatic precipitator in series Boilers 3 & 4 are fitted with a mechanical dust collector and an electrostatic precipitator in series Opacity when Boilers 3 & 4 are operating is typically less than 10% Opacity when Boilers 3 & 4 are operating is typically less than 10% Emissions rate is lb/mmBTU Emissions rate is lb/mmBTU

Electrostatic Precipitator

Fabric Filter or Baghouse Baghouses were originally supplied with Boilers 1 & 2 Baghouses were originally supplied with Boilers 1 & 2 Collect particulate by filtering through 1,354 filter bags, each 6 in diameter by 14 feet long Collect particulate by filtering through 1,354 filter bags, each 6 in diameter by 14 feet long Collection efficiency exceeds 99.5% Collection efficiency exceeds 99.5% Opacity on Boilers 1 & 2 is less than 5% Opacity on Boilers 1 & 2 is less than 5% Emissions rate is lb/mmBTU Emissions rate is lb/mmBTU

Fabric Filter or Baghouse

Fabric filters are used on many material handling systems in the plant as well Fabric filters are used on many material handling systems in the plant as well Ash handling systemsAsh handling systems Coal, lime and ash silo ventsCoal, lime and ash silo vents Coal handling system transfer pointsCoal handling system transfer points Primary use is to control fugitive dusts as materials are transferred from conveyor to conveyor, into silos, etc. Primary use is to control fugitive dusts as materials are transferred from conveyor to conveyor, into silos, etc.

Circulating Fluidized Bed Boilers Burns coal in conjunction with limestone Burns coal in conjunction with limestone Limestone constituents react with the sulfur to produce CaSO 4 which is removed with the ash Limestone constituents react with the sulfur to produce CaSO 4 which is removed with the ash Eliminates more than 90% of the sulfur dioxide emissions Eliminates more than 90% of the sulfur dioxide emissions Low combustion temperatures and staged combustion reduce the emissions of nitrogen oxides Low combustion temperatures and staged combustion reduce the emissions of nitrogen oxides

Circulating Fluidized Bed Boilers

Stoker Boilers These boilers have no means of controlling sulfur dioxide or nitrogen oxide emissions These boilers have no means of controlling sulfur dioxide or nitrogen oxide emissions Fuel is purchased with sulfur contents low enough to meet the requirements Fuel is purchased with sulfur contents low enough to meet the requirements Future regulatory requirements for SO 2 or NO X will require installation of additional pollution control equipment, fuel switching or other compliance methods Future regulatory requirements for SO 2 or NO X will require installation of additional pollution control equipment, fuel switching or other compliance methods

ISU Compliance Efforts Operate equipment as efficiently as possible, minimizing coal consumption and emissions Operate equipment as efficiently as possible, minimizing coal consumption and emissions Operate pollution control equipment properly Operate pollution control equipment properly Operate most efficient units as much as possible Operate most efficient units as much as possible Continuously look for alternatives to improve performance Continuously look for alternatives to improve performance

Emissions Summary Sulfur DioxideNitrogen OxidesParticulate Matter Boiler Efficiency Percent of Steam Production DNR Limit Average DNR Limit Average DNR Limit Average Boiler 187%30%1, Boiler 287%35%1, Boiler 382%14%5,7951,067.9None Combined 32.8 Boiler 482%20%6,1781,516.8None Boiler 578%2%4, None Boiler 678%0%00None00 Total 100%18,9173, Note: All emissions are expressed in tons per year

Emissions Reduction Opportunities Continue cogeneration Continue cogeneration Reduces coal burn by 15,000 tons per yearReduces coal burn by 15,000 tons per year Reduces limestone consumption by 1,600 tons per yearReduces limestone consumption by 1,600 tons per year Reduces ash production by 2,600 tons per yearReduces ash production by 2,600 tons per year Saves over $1.5 million per yearSaves over $1.5 million per year Results in emissions reductions ofResults in emissions reductions of 37,000 tons less carbon dioxide 37,000 tons less carbon dioxide 310 tons less sulfur dioxide 310 tons less sulfur dioxide 50 tons less nitrogen oxides 50 tons less nitrogen oxides

Emissions Reduction Opportunities Conserve Energy Conserve Energy Shut off lights and equipment that you arent usingShut off lights and equipment that you arent using Utilize energy efficient devicesUtilize energy efficient devices Adjust thermostatsAdjust thermostats Energy conservation is 100% efficient at emission reductions, if you dont use the energy, there are no emissionsEnergy conservation is 100% efficient at emission reductions, if you dont use the energy, there are no emissions Saves money for other thingsSaves money for other things

Emissions Reduction Opportunities Add more pollution control equipment Add more pollution control equipment Effective but very expensiveEffective but very expensive Baghouse - $6.0 million per boilerBaghouse - $6.0 million per boiler Scrubbers - $12-15 millionScrubbers - $12-15 million Install new coal boiler - $60+ millionInstall new coal boiler - $60+ million

Emissions Reduction Opportunities Switch fuels Switch fuels Low sulfur eastern coals – costs are 25-50% higherLow sulfur eastern coals – costs are 25-50% higher Low sulfur western coals – BTU content 25% lower, not suitable for ISU boilersLow sulfur western coals – BTU content 25% lower, not suitable for ISU boilers BiomassBiomass BTU content is 40% lower, and density is 50% of coal BTU content is 40% lower, and density is 50% of coal Volume of fuel required increases nearly 4 times Volume of fuel required increases nearly 4 times Emissions of NO X increases due to fuel volatility Emissions of NO X increases due to fuel volatility Transportation costs can make biomass fuels not economical Transportation costs can make biomass fuels not economical Natural gas – costs are % higherNatural gas – costs are % higher

Emissions Reduction Opportunities Wind Energy Wind Energy ISU is participating in development of a wind farm near AmesISU is participating in development of a wind farm near Ames Cost of energy appears economicalCost of energy appears economical Have requested 5 megawatts of capacity which would provide about 7% of current energy consumptionHave requested 5 megawatts of capacity which would provide about 7% of current energy consumption Capacity factor expected to be 37-38%Capacity factor expected to be 37-38%

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