HomeMy WebLinkAboutRES-2010-054 Resolution Regarding the Use of Coal As An Energy Source for the Co-Generation Facility of UNC at Chapel HillY~ • a.o~o -- a-
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RESOLUTION 7 d
ORANGE COUNTY BOARD OF COMMISSIONERS
REGARDING THE USE OF COAL AS AN ENERGY SOURCE
FOR THE CO-GENERATION FACILITY OF
THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL
WHEREAS, medical research has yielded compelling evidence that toxic
chemicals, including mercury, arsenic, lead and particulate matter, emitted by
coal-fired plants can adversely affect human health:
WHEREAS, the UNC-Chapel Hill cogeneration plant is responsible for more than
320,000 metric tons of greenhouse gas emissions every year, contributing to
global warming; and
WHEREAS, coal mining is often socially and environmentally destructive, and
UNC's coal may be extracted using mountain top removal, a method that causes
egregious damage to the environment and communities of Appalachia; and
WHEREAS, the energy cost savings from burning coal are actually shifted to
increased public health and environmental costs;
WHEREAS, on April 20 a representative of the group Citizens for aCoal-Free
Community presented a petition to the Board of Commissioners' consideration;
and
WHEREAS, on May 7 UNC Chancellor Holden Thorp issued a statement
adopting the recommendations of his appointed Energy Task Force, committing
the campus to be coal-free by the year 2020; and
WHEREAS, the Commission for the Environment has reviewed the petition and
the status of the plant with recommendations regarding needed future
monitoring:
NOW, THEREFORE, BE IT RESOLVED that the Orange County Board of
Commissioners thanks the Citizens for aCoal-Free Community for raising this
issue and shares the interest in public health and the move away from coal as an
energy source for the UNC co-generation facility.
BE IT FURTHER RESOLVED that the Board applauds the action of Chancellor
Thorp to make the university coal-free by the year 2020, thanks the Commission
for the Environment for its thoughtful consideration of the implications of this
planned energy source change, and encourages the University to proceed on
this path towards acoal-free future at all due speed, mindful of the implications
and monitoring needs that are critically-important to assess the impact of this
change.
This, the 15th day of June, 2010.
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Valerie P. Foushee, Chair
Board of County Commissioners
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D nna Bak r, Clerk to the Board
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ORANGE COUNTY
COMMISS[ON FOR THE ENVIRONMENT
MEMORANDUM
To: Board of County Commissioners
From: Commission for the Environment
Date: June 14, 2010
Subject: Petition submitted by Citizens for aCoal-Free Community
On April 20, 2010 the Board of Commissioners received a petition from the Citizens
for aCoal-Free Community, requesting the Board join others in asking the University
of North Carolina at Chapel Hill to eliminate the burning of coal through a mix of
energy conservation, energy efficiency, and using clean renewable energy sources.
Subsequently, the Board asked the Commission for the Environment (CFE) to
consider the petition and report back to the Board. The following is the CFE's
response.
The coal-fired plant referred to in the petition is UNC's cogeneration plant that has
been operating since 1991. Cogeneration means that the plant generates both
electricity and steam as well as steam heat (for use in both building heating and
cooling), thereby operating at high efficiency because it uses the energy in the steam
to turn a turbine generator and to run the various heating and cooling operations on
campus. In most standard coal-fired electric generating plants the steam is used only
for turbine operations and the heat content of phase change from liquid water to
gaseous steam is discarded (unused). UNC's plant uses circulating fluidized bed
(CFB) technology for cogeneration, which requires the use of at least 50% solid fuel
though there is some flexibility in the nature of the solid fuel.
Currently the plant burns coal (100,000 tons/year) and natural gas to annually
generate 32 megawatts of electricity. The plant has won awards from the U.S.
Environmental Protection Agency and U.S. Department of Energy for its efficiency
and reduction of greenhouse gases (GHG's) compared to other fossil fuel fired
alternatives, and the plant could operate for an additional 30 to 40 years.
The CFE agrees that coal combustion is harmful to the environment and that costs of
using coal are externalized as they are for all fossil fuels. Petitioners rightfully point
out that coal combustion is a primary source of GHG's. UNC's plant is the largest
stationary emitter of C02 in Orange County (~ 340,000 tons/yr), although the amount
of C02 attributed to the burning of coal and natural gas has not been reported on an
individual basis. Nitrous oxides (NOx) and sulfur dioxide (S02) emissions from the
plant are relatively low, 500 tons and 150 tons/yr, respectively. Combustion
temperatures of approximately 1,800° F versus 2,800° F in apulverized-fired boiler
keep NOx emissions low. Limestone is added to the fluidized bed to reduce S02.
Calcium sulfate (CaSO4) is precipitated as a by-product. It should be noted that the
reaction between limestone and the S02 in the gas is, itself, a generator of C02 gas.
Along with GHG's, the facility produces approximately 25,000 tons/yr of fly ash, which
is beneficially utilized locally as structural fill and an agricultural and horticultural-soil
supplement.
To eliminate the use of coal, as requested by the petitioners, will require its
replacement by another solid fuel such as wood pellets or torrefied wood (biomass).
Wood pellets are produced by compressing wood of nearly any variety that has first
passed through a hammer mill and is then squeezed through a die having holes of 6
to 8 mm diameter. The pellets have a heating value of approximately 7,450 Btu/Ib, a
high density (specific gravity > 1), a moisture content of less than 10%, good
structural strength, and low ash content. Torrefied wood is a pyrolized product
resulting from heating wood in an inert atmosphere at a temperature of 392° F to
536° F. It has a heating value of approximately 9,500 Btu/Ib (for comparison
Appalachian coal has a heating value of 12,000 Btu/Ib), is hydrophobic (stored
moisture content ~ 3%), and has an optimum durability/friability ratio.
Assuming there is an adequate supply of biomass to eliminate the burning of coal,
CO2, NOx, and SO2 will continue to be emitted. CO2 emissions from biomass
combustion might be accounted for differently than with fossil fuels. Nevertheless,
biomass combustion releases CO2. The use of biomass is argued to have low net
lifecycle impact because CO2 released is ultimately consumed in the regrowth of the
trees used to produce the wood pellets or torrefied wood. However, if best practices
and sustainable biomass management are not followed, then a large net amount of
CO2 will be released into the air. Depending on the efficiency of biomass combusted
in CFB, CO2 emissions might be less, equal, or more than those emitted by coal
combusted in CFB. An evaluation of actual fuel burned, including tonnages burned,
and the operating conditions of the facility would be required to calculate CO2
emissions for comparison. NOx and SO2 emissions should be less. There will be
some NOx produced during combustion, almost no SO2, and much less fly ash.
Petitioners also referred to the destructiveness of mining coal by mountain top
removal. Indeed, UNC may be using some tonnage of such coal. Verification of
underground-mined coal is not a trivial matter. Furthermore, there will be an annual
cost premium of $1,000,000 or more even if it can be verified as underground-mined
coal.
Since the petition was submitted to the Board, Chancellor Holden Thorp (on May 4,
2010) accepted the UNC-Chapel Hill Energy Task Force recommendations setting
UNC on a course to end coal use by 2020. Although there are a number of steps to
be taken in the evaluation of this fuel switch, the objective of the petition has largely
been met. This is an important symbolic step in beginning to move away from fossil
fuels to renewable energy sources and a positive step for the environment. In
conclusion, the CFE recommends monitoring the progress of the fuel switch as
choices are made by UNC to accomplish its goal of ending the use of coal.
Copies: Frank Clifton, Jr., County Manager
David Stancil, Environment, Agriculture, Parks and Recreation Director
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