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Along with GHG's, the facility produces approximately 25,000 tons/yr of fly ash, which <br />is beneficially utilized locally as structural fill and an agricultural and horticultural-soil <br />supplement. <br />To eliminate the use of coal, as requested by the petitioners, will require its <br />replacement by another solid fuel such as wood pellets or torrefied wood (biomass). <br />Wood pellets are produced by compressing wood of nearly any variety that has first <br />passed through a hammer mill and is then squeezed through a die having holes of 6 <br />to 8 mm diameter. The pellets have a heating value of approximately 7,450 Btu/Ib, a <br />high density (specific gravity > 1), a moisture content of less than 10%, good <br />structural strength, and low ash content. Torrefied wood is a pyrolized product <br />resulting from heating wood in an inert atmosphere at a temperature of 392° F to <br />536° F. It has a heating value of approximately 9,500 Btu/Ib (for comparison <br />Appalachian coal has a heating value of 12,000 Btu/Ib), is hydrophobic (stored <br />moisture content ~ 3%), and has an optimum durability/friability ratio. <br />Assuming there is an adequate supply of biomass to eliminate the burning of coal, <br />CO2, NOx, and SO2 will continue to be emitted. CO2 emissions from biomass <br />combustion might be accounted for differently than with fossil fuels. Nevertheless, <br />biomass combustion releases CO2. The use of biomass is argued to have low net <br />lifecycle impact because CO2 released is ultimately consumed in the regrowth of the <br />trees used to produce the wood pellets or torrefied wood. However, if best practices <br />and sustainable biomass management are not followed, then a large net amount of <br />CO2 will be released into the air. Depending on the efficiency of biomass combusted <br />in CFB, CO2 emissions might be less, equal, or more than those emitted by coal <br />combusted in CFB. An evaluation of actual fuel burned, including tonnages burned, <br />and the operating conditions of the facility would be required to calculate CO2 <br />emissions for comparison. NOx and SO2 emissions should be less. There will be <br />some NOx produced during combustion, almost no SO2, and much less fly ash. <br />Petitioners also referred to the destructiveness of mining coal by mountain top <br />removal. Indeed, UNC may be using some tonnage of such coal. Verification of <br />underground-mined coal is not a trivial matter. Furthermore, there will be an annual <br />cost premium of $1,000,000 or more even if it can be verified as underground-mined <br />coal. <br />Since the petition was submitted to the Board, Chancellor Holden Thorp (on May 4, <br />2010) accepted the UNC-Chapel Hill Energy Task Force recommendations setting <br />UNC on a course to end coal use by 2020. Although there are a number of steps to <br />be taken in the evaluation of this fuel switch, the objective of the petition has largely <br />been met. This is an important symbolic step in beginning to move away from fossil <br />fuels to renewable energy sources and a positive step for the environment. In <br />conclusion, the CFE recommends monitoring the progress of the fuel switch as <br />choices are made by UNC to accomplish its goal of ending the use of coal. <br />Copies: Frank Clifton, Jr., County Manager <br />David Stancil, Environment, Agriculture, Parks and Recreation Director <br />2 <br />