Addendum 1 to the Illinois Greenhouse Gas Emissions Inventory and Projections Overview
Report: Detailed Greenhouse Gas Emissions Illinois Sectors
Prepared for the Illinois Climate Change Advisory Group
March 28, 2007
World Resources Institute
Overview
At the request of the members of the Illinois Climate Change Advisory Group (CCAG), the
World Resources Institute (WRI) assembled this addendum to the Illinois greenhouse gas (GHG)
emissions inventory, which presents more detailed analysis of sectoral GHG emissions data for
Illinois. The information contained in this addendum is divided into sections based on major
economic sectors as defined by WRI’s Climate Analysis Indicators Tool (CAIT-US). These
sections are: Electricity Generation, Industry, Transportation and Land-use, Land-use Change
and Forestry (LULUCF).
Data are derived from several sources, including the Energy Information Administration (EIA),
Illinois state agencies, and. CAIT-US. For a complete description of the CAIT tool, its data
sources, and relevant caveats and data uncertainties, please see Appendix A of the “Illinois
Greenhouse Gas Emissions Inventory and Projections” report.
Electricity Generation
Net electricity exports (figure 1) are calculated as the difference between Illinois’ electricity
generation total and its total electricity sales, using data from the EIA. According to recent
estimates, Illinois ranks among the top ten states in total exports of electricity, exporting nearly
50 million MWH in 2005. Illinois electricity exports have steadily increased, more than doubling
since 1990, with the exception of a clear decrease in 1997-1998. During this time, a portion of
Illinois’ nuclear generation capacity was temporarily off-line; this reduced total state electricity
generation (see figure 2) as well as net electricity exports but not GHG emissions since some of
the lost , zero-emitting nuclear generation was made up by increased coal generation.
1
Illinois Electricity Exports 1990-2005
Thousand MWH
60,000
50,000
40,000
Illinois Electricity
Exports 1990-2005
30,000
20,000
10,000
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
0
Figure 1. Source: Energy Information Administration, Electric Power Annual 2005
http://www.eia.doe.gov/cneaf/electricity/epa/epa_sprdshts.html; WRI calculations
Illinois Electric Generation by Fuel 1990-2005
200,000
180,000
Other
160,000
Hydroelectric
Conventional
Thousand MWH
140,000
Other Renewables
120,000
Other Gases
100,000
Petroleum
80,000
Natural Gas
60,000
Coal
40,000
Nuclear
20,000
0
1990
1995
2000
2005
Figure 2.
Source: EIA Electric Power Annual 2005 (http://www.eia.doe.gov/cneaf/electricity/epa/epa_sprdshts.html)
Figure 2 highlights the principal fuel sources for electricity generation in Illinois. The
overwhelming majority of electricity is produced from coal and nuclear energy sources, which,
in 2005, accounted for 47.5 percent and 48.0 percent of total generation, respectively. Absolute
generation from both sources has grown substantially since 1990. More specifically, generation
from nuclear power increased by approximately 30 percent between 1990 and 2005, while
electricity generation from coal increased by 68 percent over the same time period. Other fuel
sources, including natural gas and renewables, which constitute much smaller shares of total
electricity generation, show trends since 1990 that have been much more variable.
2
Since 1990, coal’s share of total generation has been gradually increasing, while the share
derived from nuclear has decreased (figure 3). Noticeably, the share of natural gas for electricity
generation has grown only slightly since 1990, despite the rapid expansion of natural gas
capacity in the late 1990s (figure 4). The fact that this capacity growth has not been mirrored by
a similar rise in electric generation from this source (figure 2), indicates that Illinois’ increase in
electricity generation from coal has largely spurred overall growth in GHG emissions in this
sector (see below). This is significant considering no new coal capacity was installed over this
fifteen year time span (see figure 4), instead, existing coal plants increased their generation of
electricity and in turn emissions. The share of renewable energy such as wind and solar power
(represented as “other renewables” in figures) accounted for less than one percent of total
generation in this time period.
In 2003, greenhouse gas (GHG) emissions from coal accounted for 83 million metric tons, or 97
percent, of the total emissions attributable to the electricity generation sector in Illinois with
natural gas accounting for the majority of the remaining 3 percent followed by oil (CAIT, WRI).
The proportion of coal-based emissions to total emissions has been fairly constant since 1990.
However, between 1990 and 2003, total emissions from electricity generation grew nearly 53
percent—approximately twice the value of the percentage increase in emissions of this sector at
the national level—with roughly equivalent increases in coal-produced emissions. This increase
occurred primarily due to increased generation from existing coal fired power plants.
Like many states in the 1990s, Illinois experienced a rapid expansion in natural gas fired electric
generation capacity. While the installed capacity of nearly all other types of power plants held
steady or declined between 1990 and 2005 (such as the case of oil fired power plants) Illinois’
installed natural gas capacity increased by over 760 percent (see figure 4). This capacity has
primarily been used to serve peak load demand rather than base load power, running only when
demand is at its highest. This is due to the relatively high cost of natural gas compared to coal
and the fact most modern natural gas power plants can be ramped up or down much more easily
than coal or nuclear plants to serve demand. The paradoxical result of the rush to gas since 1990
is that natural gas power plants account for 35 percent of total installed capacity but less than 4
percent of total generation and only 2 percent of GHG emissions from this sector.
According to EIA, an additional 4,524 MW of installed electric generation capacity is planned
for operation by 2010 (see figure 4). Coal power plants account for 3839 MW of this new
capacity. Meanwhile, no new nuclear, oil fired power plants and approximately 400 MW of
natural gas plants are planned before 2010. A small but significant amount (275 MW) of wind
power should be on line and operational within this time period. In-state and regional electricity
demand and electricity market dynamics in the coming years notwithstanding, new coal plants
are likely to drive further increases in GHG emissions in this sector in the near future.
3
Illinois Electricity Generation by Fuel 1990-2005, percent of total
100%
90%
Other
80%
Hydroelectric
Conventional
70%
Other Renewables
60%
Other Gases
50%
Petroleum
40%
Natural Gas
30%
Coal
20%
Nuclear
10%
0%
1990
1995
2000
2005
Figure 3.
Source: EIA Electric Power Annual 2005 (http://www.eia.doe.gov/cneaf/electricity/epa/epa_sprdshts.html)
Illinois Existing Nameplate Capacity and Planned Capacity Additions
by Fuel 1990-2010
Installed
Planned
60
Other
50
Other
Renewables
Hydroelectric
Thousand MW
40
Other Gases
30
Natural Gas
Petroleum
20
Nuclear
10
Coal
0
1990
1995
2000
2005
2010
Figure 4.
Source: EIA Electric Power Annual 2005 (http://www.eia.doe.gov/cneaf/electricity/epa/epa_sprdshts.html)
4
Industry
The industrial sector in Illinois produced approximately 38 MtCO2eq in 2003, representing about
14 percent of the state’s total GHG emissions. In 2003, emissions from coal, petroleum, and
natural gas sources accounted for 25, 39, and 36 percent of total emissions, respectively (CAIT,
WRI). In general, the proportional composition of industrial emissions remained relatively
constant between 1990 and 2003, with only slight decreases observed in the percentage
contribution from coal and minor increases seen in the percent emissions from natural gas (in
both instances, these changes are on the order of 3-6 percent). Of note, however, is that Illinois
has experienced a nearly 15 percent reduction in emissions within this sector since 1990, a
change significantly greater in magnitude than the comparable national value of -1.6 percent.
Figure 5 compares total industrial GHG emissions (broken down by fuel) to total energy
consumption in the industrial sector between 1990 and 2003. This analysis reveals that,
generally, industrial energy consumption and emissions follow similar trends, as one might
expect, rising until around 1997 and gradually declining in recent years. Difficulties arise,
however, when trying to interpret the driving forces of the observed trends. Recent reductions in
emissions, are partially the result of fuel switching away from coal towards less carbon intensive
natural gas. The reduction in overall energy consumption is also a factor. This decline in
energy use and emissions could be due to increasing energy efficiency, the result of declining
activity overall within this sector, or a combination of both.
Illinois Industry Energy Consumption and CO2 Emissions 1990-2003
1600
Emissions (Million Tonnes CO2)
1400
50
1200
40
1000
30
800
600
20
400
10
200
Energy Consumption (Trillion BTUs)
60
Natural Gas
Petroleum
Coal
Energy
Consumption
0
0
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Figure 5.
Sources: Energy Consumption--EIA (http://www.eia.doe.gov/emeu/states/sep_use/ind/use_ind_il.html) and Emissions--CAIT
(http://cait.wri.org)
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Transportation
The information presented below regarding the transportation sector in Illinois comes from the
U.S. Department of Transportation’s Federal Highway Administration (FHWA; fuel use) and the
U.S. Department of Energy’s EIA (emissions). These data were compiled and analyzed by
members of the Illinois EPA.
The following figure 6 is reproduced from FHWA’s "Highway Statistics 2005" publication Table
MF-21, Motor Fuel Use (http://www.fhwa.dot.gov/policy/ohim/hs05/xls/mf21.xls). The figure
below reports Illinois motor fuel use for 2005 in thousands of gallons. Highway use and
nonhighway use categories combine gasoline and gasohol.
Illinois Motor Fuel Use, 2005 (thousands of gallons)
SUMMARY OF TOTAL USE
Highway
Non-Highway
percent
Non-Highway
fuel use
Total Motor change from
Grand
last year
(gasoline only)
Fuel Use
Total
-0.21
158,305 6,713,901
6,555,596
(Gasoline and gasohol)
HIGHWAY USE
Private Use
Public Use
Private &
Civilian State, County Public Use
Commercial Federal & Municipal
Total
4,960,365 6,429
86,451
92,880
Highway
Use Total
5,053,245
Special Fuels
diesel & alternative
Private & Commercial Special
Fuel On-Hwy Use
1,502,351
NONHIGHWAY USE
Private Use Public Use
Private &
State, County Non-Highway
Commercial
& Municipal
Use Total
153,798
4,507
158,305
Figure 6.
Source: FHWA (http://www.fhwa.dot.gov/policy/ohim/hs05/xls/mf21.xls). Notes from FHWA: “This table is one of a series
giving an analysis of motor-fuel consumption, based on reports from State motor-fuel tax agencies. Gasohol is included with
gasoline. In order to make the data uniform and complete, public use and nonhighway use were estimated by the Federal
Highway Administration. These estimates may not be comparable to data for prior years due to revised estimation procedures.
The resulting volumes differ in many cases from the unadjusted data reported in table MF-2. For some States, data are not
comparable to prior years due to changes in data analysis and/or improvements in reporting procedures. All data are subject to
review and revision.”
In summary, according to 2005 estimates, motor fuel in Illinois is principally consumed on
highways by private and commercial users. Discounting “special fuels (primarily diesel),”
gasoline and gasohol (ethanol) highway consumption accounts for 97 percent of all state-wide
motor fuel use when losses due to evaporation and handling (here, estimated at around 14,000
gallons) are also considered.
Distillate fuel (primarily diesel fuel) use in Illinois for 2005 is displayed in table 1, below. Onhighway activities account for approximately 82 percent of distillate consumption in the
transport sector and 70 percent of total distillate consumption. The transportation sector as a
whole represents 84 percent of Illinois distillate use.
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Table 1. Adjusted Annual Distillate Usage by Sector, thousand gallons, for Illinois, 2005
Sector
Residential
Commercial
Industrial
Oil Company
Farm
Electric Power
Thousand
gallons
10,715
42,128
78,642
68
195,756
15,909
Transport
Railroad
Vessel Bunkering
On-Highway
Military
Off-Highway
All Other
62,851
124,933
1,460,631
758
139,336
0
Total for Transport
Grand Total
1,788,509
2,131,727
Source: EIA (http://tonto.eia.doe.gov/dnav/pet/pet_cons_821dsta_dcu_SIL_a.htm)
Illinois’ 2005 CO2 emissions by fuel type and transport sub-sector are delineated below.
Table 2. CO2 Emissions from the Transportation Sector in Illinois by Fuel Type, 2005 (Metric tons) 1
% of total
Transportation
Transportation Fuel Type
tonnes/year
Aviation Gasoline
35,853
0.0%
Distillate (Nos. 1, 2, & 4 Fuel Oil)
3,212
0.0%
Diesel Fuel (EF same as Distillate's)
16,849,427
21.4%
Jet Fuel
13,836,019
17.6%
Kerosene
--Liquified Petroleum Gases (LPG)
--Motor Gasoline
45,842,054
58.3%
Petroleum Coke
--Residual Fuel (Nos. 5 & 6 Fuel Oil)*
Propane
Total Transportation Sector CO2
-1,997,522
78,564,087
-2.5%
100.0%
Source: Illinois EPA and DOT Calculations of Prime Supplier Sales Volumes data from EIA website
(http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_SIL-a.htm).
Notes: Emission factors used in calculations are from USDOE's Energy Information Administration (EIA) at
http://www.eia.doe.gov/oiaf/1605/coefficients.html. Residual fuel is used chiefly by ships. Reported use varies widely from year
to year, and is not available for 2005. Estimates for 2004 were about 74,500 gal/day. "--" means data are not available and are
assumed to be negligible.
1
Due to the use of state data in some categories as well as methodological differences transportation emissions data
may differ somewhat from data sourced from CAIT-US.
7
Table 3. CO2 Emissions from the Transportation Sector in Illinois by Activity, 2005 (metric tons)
Activity
On-Highway
Aviation
Off-Highway
Marine
Railroad
Other sources
Total
% of total
tonnes/year Transportation
57,499,301
73.2%
13,871,872
17.7%
2,689,517
3.4%
1,179,460
1.5%
589,730
0.8%
733,473
0.9%
76,563,353
97.5%
Source: Illinois EPA and DOT Calculations of Prime Supplier Sales Volumes data from EIA website
(http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_SIL-a.htm).
Note: Emission factors used in calculations are from USDOE's Energy Information Administration (EIA) at
http://www.eia.doe.gov/oiaf/1605/coefficients.html. This table does not include data for residual fuel or propane as these fuels
are used in a variety of activities, this is also why percentages to not sum to 100.
Not surprisingly, motor gasoline, diesel and jet fuel, which constitute the majority of fuel use in
the transportation sector (see table 2), comprise nearly 98 percent of transportation CO2
emissions with motor gasoline accounting for 59 percent of total emissions. With regards to
emissions broken down to activity, on-highway transport is by far the largest source of emissions
at 73 percent. Aviation emissions are also substantial, comprising nearly 18 percent of Illinois’
transportation emissions. Marine and rail sources make much smaller contributions to total
emissions, 1.5 and 0.8 percent of total emissions respectively.
It is important to note that for all transport modes and for large interstate travel modes such as
aviation, marine and rail in particular, emissions data are assigned to Illinois because that is
where the fuel was sold. This methodology is used because assigning emissions at the location
of combustion is far more difficult than doing so at the point of sale. Due to the nature of these
sources, associated emissions may actually take place outside of the state but are accounted for in
Illinois’ total emissions.
Table 4 (below) provides a brief summary of trends in vehicle-miles traveled (VMT), population,
and emissions between 1990 and 2003. It is notable that during this time period the increase in
VMT was significantly greater than growth in emissions, likely due to increased automobile
efficiencies. However, both VMT and VMT per capita estimates grew at annual rates that
outpace population growth, suggesting that vehicles are being driven further and more often in
Illinois than in the early 1990s. Economic development and urban sprawl are the most likely
drivers of this trend.
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Table 4.
Transportation Sector Growth in Illinois
Illinois
1990
2003
Growth
Annual Rate
Vehicle-Miles Traveled (billions)
83.6
106.5
27.3%
1.9%
Population (millions)
11.5
12.6
10.4%
0.8%
7302.7
8416.0
15.2%
1.1%
55.3
65.5
18.5%
1.3%
Vehicle-Miles Traveled per capita
GHG Emissions from Transport (MTCO2Eq)
Sources: VMT: IL Department of Transportation (http://www.dot.state.il.us/travelstats/2005its.pdf); Population: U.S. Census
Bureau (http://www.census.gov/popest/archives/2000s/vintage_2001/CO-EST2001-12/CO-EST2001-12-17.html and
http://www.census.gov/popest/states/NST-ann-est.html); Emissions: CAIT (http://cait.wri.org)
Land Use, Land Use Change and Forestry (LULUCF), and Land Cover
Available CAIT-U.S. data on LULUCF are highly uncertain due to incomplete proxy data sets as
well as the variable nature of the biological systems to which the data relate. The following data
should be considered illustrative of trends in this sector and taken only as a qualitative
assessment rather than an authoritative and quantitative study. Please see the “Illinois
Greenhouse Gas Emissions Inventory and Projections” report for important caveats and
additional information on this topic.
The data provided below show total CO2 emissions (not total GHG emissions) and the amount of
carbon sequestered (primarily by forests) as a percent of that total. The data give an indication
that the LULUCF contribution to carbon sequestration has been steadily declining since the early
1990s. Specifically, in 1990, CO2 emissions totaled around 194 MtCO2eq, while LULUCF
sequestered approximately 14.3 MtCO2 (~7.4 percent of total CO2 emissions). In 2003, CO2
emissions totaled 235 MtCO2eq., while LULUCF sequestered only 7.4 MtCO2eq., or 3.2 percent
of total CO2 emissions. The inverse trends of these two variables suggest Illinois’ LULUCF
sector is on its way to losing its status as a net “sink” of carbon dioxide.
9
Illinois CO2 Emissions and Percent CO2 Sequestered by LULUCF,
1990-2003
8%
300
7%
250
Total CO2
Emissions
200
5%
4%
150
3%
100
2%
% Sequestered
Million Tonnes CO2
6%
LULUCF
CO2
Storage as
a % of
Total CO2
Emissions
50
1%
0
1990
0%
1992
1994
1996
1998
2000
2002
Figure 7.
Source: CAIT (http://cait.wri.org)
Given the considerable uncertainty surrounding the data presented above, a second source of data
on LULUCF trends in Illinois is included here. Table 5, reproduced from a paper by Dr. Donald
Luman of the Illinois State Geological Survey, provides some estimates of how the share of state
land area under various land uses changed through the 1990s. Comparing spatial extents of major
land cover categories between 1991-1995 and 1999-2000, the table shows that, most
significantly, land uses that have relatively low or no carbon storage capacity namely agricultural
land and urban areas have increased in land area. Conversely, land uses that have a relatively
high capacity to store carbon such as rural grassland and forested areas have declined
considerably. The results of this particular study provide some insight as to why there is a
precipitous decline in LULUCF sequestration in Illinois during this time period.
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Table 5.
Illinois Surface Area by Principal Land Cover Categories
% State Area, % State Area,
%
Difference
1991-1995
1999-2000
60.37
64.76
4.39
Agricultural Land
18
11.64
-6.36
Rural Grassland
11.59
11.51
-0.08
Upland Forest
3.37
4.54
1.17
Urban Built-Up
1.81
1.81
0
Urban Open Space
Nonforested Wetland
0.51
0.69
0.18
Forested Wetland
2.45
3.13
0.68
Shallow Water Wetland
0.49
0.11
-0.38
Surface Water
1.35
1.67
0.32
Barren and Exposed Land
0.05
0.1
0.05
Clouds
0
0.03
0.03
100.00%
100.00%
0.00%
Totals:
Source: Adapted from Table 2 in Luman, 2003. “Land Cover of Illinois 1999-2000 & Land Cover of Illinois 1991-1995: An
Assessment of the Potential for Land Cover Change.”
11