Typically when a new building technology is evaluated the
energy performance of a baseline building is compared to the
energy and life-cycle costs of alternatives to determine
cost-effectiveness. But what if the lowest energy or
life-cycle cost alternative is not the cleanest or lowest
environmental impact? By calculating environmental impact,
designers can compare alternatives not only in terms of their
energy performance but also their environmental
performance–working towards a more sustainable design (Liesen
1997; Stroot, Nemeth, and Fournier 1996). Environmental
impacts are quantified, in part, by modeling the amount of
emissions and in EnergyPlus this is done using the input
objects “EnvironmentalImpactFactors,”
“FuelFactors,”
and “Output:EnvironmentalImpactFactors.”
Based on emissions factors entered by the user, EnergyPlus
calculates the mass or volume of thirteen different
pollutants: CO2 (carbon dioxide), CO (carbon
monoxide), CH4 (methane), NOx (nitrogen
oxides), N2O (nitrous oxide), SO2
(sulphur dioxide), PM (particulate matter), PM10
(particulate matter 10>PM10>2.5 microns),
PM2.5 (particulate matter<2.5 microns),
NH3 (ammonia), NMVOC (non-methane volatile organic
compounds), Hg (mercury), and Pb (lead) as well as water
consumed through evaporation in thermo- and hydro-electric
generation and high- and low-level nuclear waste from nuclear
electricity generation for on- and off-site energy production.
Note that while these comprise the largest proportion of
pollutants, more than one hundred other pollutants are emitted
from fossil fuel combustion or electricity generation. Much of
the information compiled here for fossil fuel combustion comes
from AP-42 Compilation of Air Pollutant Emission
Factors (EPA 1998a, 1998b, 1996). For more information on
pollutants, see the U.S. Environmental Protection Agency (EPA)
Clearinghouse for Inventories & Emission Factors
(www.epa.gov/ttn/chief/efinformation.html).
EnergyPlus models energy performance of on-site fossil
fuels and purchased electricity (generated from a variety of
fuels including natural gas, oil, gasoline, diesel, coal,
hydroelectric, nuclear, wind, solar power, and biomass). The
energy performance calculated by EnergyPlus is converted into
a mass or volume of pollutants emitted. From a baseline
building, alternative energy and pollution saving technologies
can be explored, and the energy savings and pollution
reduction can be calculated. Figure 341 and Figure 342
illustrate a comparison of two buildings simulated using
Chicago weather data in EnergyPlus and the calculated
pollutant levels (based on U.S. national average pollutants)
(Crawley 2003).
To calculate the mass or volume of each pollutant,
consumption is multiplied by an emissions factor for each fuel
(natural gas, electricity, fuel oil, diesel, or coal). In
future versions, users will be able to schedule how the
emissions factors by time of day, month, season and year. For
electricity, the mix of generation fuel sources–whether
utility, state or regional–is used to adjust the emission
factors. If a user has emissions factors specific to the
building site and equipment, these can be entered directly.
There are no default emissions factors.
EPA categorizes pollutants as either Criteria Pollutants or
Hazardous Pollutants. Criteria pollutants are the six
substances for which EPA has set health-based standards,
including carbon monoxide (CO), nitrogen oxides
(NOx), sulfur dioxide (SO2), and
particulate matter (PM10 and PM2.5), ozone (O3),
and lead (Pb). Because ozone is created in atmospheric
photochemical reactions of volatile organic compounds,
ammonia, and other substances rather than direct
building-related energy emissions, we do not calculated ozone
emissions in EnergyPlus. But we do include ozone precursors:
methane (CH4), non-methane volatile organic
compounds (NMVOC), and ammonia (NH3). Hazardous
pollutants are substances that are known or suspected to cause
serious health problems such as cancer. We include typical
hazardous substances associated with energy production and use
including lead (Pb) and mercury (Hg). We also include
CO2 (carbon dioxide) since it is largest greenhouse
gas in terms of impact.
Example Annual Atmospheric
Pollutants and Water ConsumptionExample Annual Total Carbon
Equivalent for Major Greenhouse Gases
The Intergovernmental Panel on Climate Change has studied
the effects on the relative radiative forcing effects of
various greenhouse gases. This effect, called Global Warming
Potential (GWP), is described in terms of the Carbon
Equivalent of a particular greenhouse gas. This equivalent is
based on a factor of 1.0 for carbon. This group of gases
includes carbon dioxide (CO2), carbon monoxide,
nitrous oxide, methane, halocarbon emission,
hydrofluorocarbons (HFC), perfluorocarbons (PFC), and
chlorofluorocarbons (CFC). For building energy use, the main
gases of concern are carbon dioxide, carbon monoxide, methane,
and nitrous oxide. Although carbon monoxide has a relatively
short life, CO emissions into the atmosphere may have a
significant impact on climate forcing due to chemical impact
on CH4 lifetime, and tropospheric O3 and
CO2 photochemical production normally reacts to
produce carbon dioxide, but it can’t be ignored since it is
produced in incomplete combustion and the carbon remains to
interact as CO2.Yetthere is no agreement on its
carbon equivalent (IPCC 2001). The carbon equivalent of carbon
dioxide, methane, and nitrous oxide are calculated and then
multiplied by their GWP on a 100 year time frame. The Carbon
Equivalents of the following gases have been determined and
used in the program are shown in the following table.
Carbon Equivalents (IPCC 2001)
Gas
Carbon Equivalent
NOx
80.7272
CH4
6.2727
CO2
0.2727
The resulting carbon equivalents by fuel type are shown in
the output of the program along with the individual gas
pollutants.
Emission factors for on-site fossil fuel consumption are
based on Section 1.4 Natural Gas Combustion in EPA (1998a)
Table 94 shows the greenhouse gas and precursors and criteria
pollutant emissions factors for natural gas. Similar emissions
factors are shown for residual fuel oil (No. 4 and No. 6 fuel
oil) [Table 95], distillates (No. 1 and No. 2 fuel oil) [Table
96], residential oil furnace [Table 97], LPG (butane and
propane) [Table 98], gasoline and diesel [Table 99], and coal
[Table 100] in the indicated tables. Note that a zero for a
pollutant in the table may mean that no data were available,
not that there are no emissions of that pollutant.
Emission Factors for Natural Gas
Pollutant
Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
50.23439
Carbon Monoxide (CO)
3.51641E-02
Methane (CH4)
9.62826E-04
Nitrogen Oxides
(NOX)
4.18620E-02
Nitrous Oxide
(N2O)b
9.20964E-04
Sulphur Dioxide
(SO2)c
2.51172E-04
Particulate Matter
(PM)d
3.18151E-03
Particulate Matter
(PM10)d
2.38613E-03
Particulate Matter
(PM2.5)d
7.95378E-04
Ammonia (NH3)
0e
Volatile Organic Compounds
(NMVOC)
2.30241E-03
Mercury (Hg)
1.08841E-07
Lead (Pb)
2.09310E-07
a Based on data from Tables 1.4-1, 1.4.-2 and 1.4.4 in EPA
(1998a), Natural gas heat value of 1027 Btu/ft3 based on data
for 2003 in Table A-4 in DOE (2004)
b Values shown are for uncontrolled burner. For
controlled-low NOX burner, use 0.64 lb/106 ft3,
0.000627 lb/MMBtu, 0.0002679 g/MJ
c Based on 100% conversion of fuel sulfur to
SO2. Assumes sulfur content is natural gas of 2,000
grains/106 ft3. The SO2 emission factor can be converted to
other natural gas sulfur contents by multiplying the
SO2 emission factor by the ratio of the
site-specific sulfur content (grains/106 ft3) to 2,000
grains/106 ft3.
d PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
e No data.
Emission Factors for Residual Fuel Oil (No. 4 and
No. 6 Fuel Oil)
Pollutant
No. 6 Fuel Oil Emission
Factora (g/MJ)
No. 4 Fuel Oil Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
76.77128
76.77128
Carbon Monoxide (CO)
1.53543E-02
1.53543E-02
Methane (CH4)
1.45865E-03
6.63304E-04
Nitrogen Oxides
(NOX)
1.68897E-01
6.14170E-02
Nitrous Oxide
(N2O)
3.37794E-04
3.37794E-04
Sulphur Dioxide
(SO2)b
4.82124E-01
4.60628E-01
Particulate Matter
(PM)c
2.56109E-02
2.14960E-02
Particulate Matter
(PM10)c
1.58763E-02
1.58763E-02
Particulate Matter
(PM2.5)c
5.89603E-03
5.89603E-03
Ammonia (NH3)
0d
0d
Volatile Organic Compounds
(NMVOC)
3.47006E-03
1.04409E-03
Mercury (Hg)
3.47006E-06
3.47006E-06
Lead (Pb)
4.63699E-06
4.63699E-06
a Based on data from Tables 1.3-1, 1.3-3, 1.3-8, 1.3-10,
and 1.3-12 in EPA (1998b).
b Based on 100% conversion of fuel sulfur to
SO2. Assumes 1% sulfur content. The SO2
emission factor in this table can be converted to other
natural gas sulfur contents by multiplying the SO2
emission factor by percentage sulfur content.
c PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
d No Data.
Emission Factors for Distillates (No. 1 and No. 2
Fuel Oil)
Pollutant
No. 1 Fuel Oil Emission
Factora (g/MJ)
No. 2 Fuel Oil Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
66.02330
68.47998
Carbon Monoxide (CO)
1.53543E-02
1.53543E-02
Methane (CH4)
6.63304E-04
6.63304E-04
Nitrogen Oxides
(NOX)
6.14170E-02
7.37004E-02
Nitrous Oxide
(N2O)
3.37794E-04
3.37794E-04
Sulphur Dioxide
(SO2)b
4.36061E-01
4.82124E-01
Particulate Matter
(PM)c
6.14170E-03
6.14170E-03
Particulate Matter
(PM10)c
3.31652E-03
3.31652E-03
Particulate Matter
(PM2.5)c
2.54881E-03
2.54881E-03
Ammonia (NH3)
0d
0d
Volatile Organic Compounds
(NMVOC)
1.04409E-03
1.04409E-03
Mercury (Hg)
3.47006E-06
3.47006E-06
Lead (Pb)
4.63699E-06
4.63699E-06
a Based on data from Tables 1.3-1, 1.3-3, 1.3-8, 1.3-10,
and 1.3-12 in EPA (1998b).
b Based on 100% conversion of fuel sulfur to
SO2. Assumes 1% sulfur content. The SO2
emission factor in this table can be converted to other
natural gas sulfur contents by multiplying the SO2
emission factor by percentage sulfur content.
c PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
d No data.
Emission Factors for Residential Oil
Furnace
Pollutant
Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
68.48237
Carbon Monoxide (CO)
1.53543E-02
Methane (CH4)
5.46612E-02
Nitrogen Oxides
(NOX)
5.52753E-02
Nitrous Oxide
(N2O)
1.53543E-04
Sulphur Dioxide
(SO2)b
4.36061E-01
Particulate Matter
(PM)c
2.14960E-02
Particulate Matter
(PM10)c
1.58763E-02
Particulate Matter
(PM2.5)c
5.89603E-03
Ammonia (NH3)
0d
Volatile Organic Compounds
(NMVOC)
2.18952E-03
Mercury (Hg)
3.47006E-06
Lead (Pb)
4.63699E-06
a Based on data from Tables 1.3-1, 1.3-3, 1.3-8, 1.3-10,
and 1.3-12 in EPA (1998b).
b Based on 100% conversion of fuel sulfur to
SO2. Assumes 1% sulfur content. The SO2
emission factor in this table can be converted to other
natural gas sulfur contents by multiplying the SO2
emission factor by percentage sulfur content.
c PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
d No data.
Emission Factors for LPG (butane and
propane)
Pollutant
LPG (butane) Emission
Factora (g/MJ)
Propane Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
66.02330
68.47998
Carbon Monoxide (CO)
1.53543E-02
1.53543E-02
Methane (CH4)
6.63304E-04
6.63304E-04
Nitrogen Oxides
(NOX)
6.14170E-02
7.37004E-02
Nitrous Oxide
(N2O)
3.37794E-04
3.37794E-04
Sulphur Dioxide
(SO2)b
4.36061E-01
4.82124E-01
Particulate Matter
(PM)c
6.14170E-03
6.14170E-03
Particulate Matter
(PM10)c
3.31652E-03
3.31652E-03
Particulate Matter
(PM2.5)c
2.54881E-03
2.54881E-03
Ammonia (NH3)
0d
0d
Volatile Organic Compounds
(NMVOC)
1.04409E-03
1.04409E-03
Mercury (Hg)
3.47006E-06
3.47006E-06
Lead (Pb)
4.63699E-06
4.63699E-06
a Based on data from Table 1.5-1 in EPA (1996), Higher
Heating value of 1.02 MMBtu/gal for butane and 0.915 MMBtu/gal
for propane based on data in EPA (1996).
b Based on 100% conversion of fuel sulfur to
SO2. Assumes sulphur content is 0.18 gr/100 ft3.The
SO2 emission factor can be converted to other LPG
sulphur contents by multiplying the SO2 emission
factor by the ratio of the site-specific sulphur content
gr/100 ft3 to 0.18 gr/100 ft3.
c PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
d No data.
Emission Factors for Gasoline and Diesel
Pollutant
Gasoline Emission
Factora (g/MJ)
Diesel Emission
Factora (g/MJ)
Carbon Dioxide
(CO2)
66.20808
70.50731
Carbon Monoxide (CO)
2.69561E+01
4.08426E-01
Methane (CH4)
0c
0c
Nitrogen Oxides
(NOX)
7.00774E-01
1.89596E+00
Nitrous Oxide
(N2O)
0c
0c
Sulphur Dioxide
(SO2)
3.61135E-02
1.24678E-01
Particulate Matter
(PM)b
0c
0c
Particulate Matter
(PM10)b
4.29923E-02
1.33276E-01
Particulate Matter
(PM2.5)b
0c
0c
Ammonia (NH3)
0c
0c
Volatile Organic Compounds
(NMVOC)
9.02837E-01
1.50473E-01
Mercury (Hg)
0c
0c
Lead (Pb)
0c
0c
a Based on data from Table 3.3-1 in EPA (1996), Diesel
higher heating value of 19,300 Btu/lb, and gasoline higher
heating value of 20,300 Btu/lb based on data in EPA
(1996).
b PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
c No data.
Emission Factors for Coal
Pollutant
Bituminous Emission
Factora (g/MJ)
Anthracite Emission
Factorb (g/MJ)
Lignite Emission Factorc
(g/MJ)
Carbon Dioxide
(CO2)
91.11052
99.26669
152.12646
Carbon Monoxide (CO)
8.26774E-03
1.04859E-02
8.26774E-03
Methane (CH4)
6.61419E-04
0f
0f
Nitrogen Oxides
(NOX)
1.98426E-01
3.14578E-01
2.34804E-01
Nitrous Oxide
(N2O)
4.96065E-04
0f
0f
Sulphur Dioxide
(SO2)d
6.28348E-01
6.81585E-01
9.92129E-01
Particulate Matter
(PM)e
1.65355E-01
1.74765E-01
2.18268E-01
Particulate Matter
(PM10)e
3.80316E-02
4.01960E-02
7.60632E-02
Particulate Matter
(PM2.5)e
9.92129E-03
1.04859E-02
2.18268E-02
Ammonia (NH3)
0f
0f
0f
Volatile Organic Compounds
(NMVOC)
9.92129E-04
2.14961E-02
1.32284E-03
Mercury (Hg)
6.94490E-06
2.27195E-06
2.74489E-06
Lead (Pb)
1.37245E-06
1.55541E-04
1.38898E-05
a Based on data on pulverized coal from Tables 1.1-3,
1.1-6, 1.1-18, 1.1-19 in EPA (1998a), Coal average higher
heating value of 26.0 MMBtu/ton based on EPA (1998a).
b Based on data on pulverized coal from Tables 1.2-1,
1.2-2, 1.2-3, 1.2-4, 1.2-7 in EPA (1996), Coal average higher
heating value of 24.6 MMBtu/ton based on EPA (1996).
c Based on data on pulverized coal from Tables 1.7-1,
1.7-3, 1.7-7, 1.7-14 in EPA (1998b), Coal average higher
heating value of 13.0 MMBtu/ton based on EPA (1998b).
d Based on 100% conversion of fuel sulfur to
SO2. Assumes 1% sulfur content. The SO2
emission factor in this table can be converted to other
natural gas sulfur contents by multiplying the SO2
emission factor by percentage sulfur content.
e PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 are particles smaller than 10 and
2.5 microns, respectively. Expressed in terms of coal ash
content, assumes 1% ash content. Multiply weight % ash content
of coal (as fired) by the value.
While estimating emissions from on-site fossil fuel
combustion can be fairly straight-forward, emissions from
off-site electricity is more challenging. How the electricity
is generated, i.e., from gas, oil, coal, nuclear, renewable
sources (wind, PV) or hydroelectric, and the mix of generation
determines the resulting level of emissions. While data are
available at utility and even power plant level (from the
sources cited), data are shown here for United States
national- and state-level average emissions from electricity
generation. Table 101 provides average greenhouse gas and
precursors and criteria pollutant emissions factors for the
entire United States from electricity generation. Table 102
provides average electricity emissions factors by state, for
greenhouse gas and precursors, and Table 103 for criteria
pollutant emission factors. These two tables also include a
ratio of heat input to electric output (efficiency of
electricity generation) including distribution and
transmission losses to allow calculation of source energy.
As mentioned in the introduction to this section,
EnergyPlus also calculates water consumed through evaporation
in thermo-electric and hydro-electric generation. Torcellini,
Long, and Judkoff (2004) provide data on average water
consumption by generator type by state. These data are
summarized in units suitable for EnergyPlus in Table 101, for
national and state average water consumption for
thermal-electric, hydro-electric, and Table 102 for weighted
total electricity generation.
United States National Average Emission Factors for
Electricity Generation
-
Efficiency Ratio
(J/J)
Ratio of Heat Input to
Electricity Outputa
2.253
Pollutant
Emission Factor
(g/MJ)
Carbon Dioxide
(CO2)b
168.333168
Carbon Monoxide
(CO)c
4.20616E-02
Methane
(CH4)b
1.39858E-03
Nitrogen Oxides
(NOX)a
4.10753E-01
Nitrous Oxide
(N2O)b
2.41916E-03
Sulphur Dioxide
(SO2)a
8.65731E-01
Particulate Matter
(PM)c,d
2.95827E-02
Particulate Matter
(PM10)c,d
1.80450E-02
Particulate Matter
(PM2.5)c,d
1.15377E-02
Ammonia
(NH3)c
1.10837E-03
Volatile Organic Compounds
(NMVOC)a
3.72332E-03
Mercury (Hg)c
3.36414E-06
Lead (Pb)
0e
aData based on 1999 data from eGRID
version 2.01 (EPA 2003a).
bData based on 1998-2000 average data in DOE
(2002).
cData based on tier emissions report for
criteria air pollutants in EPA (2003b).
dPM is the sum of all particulate matter
including PM10 and PM2.5. PM10 and PM2.5 stand for particles
smaller than 10 and 2.5 microns, respectively.
eNo data.
U. S. State Average Greenhouse Gas Emission Factors
for Electricity Generation, in g/MJ
State
Ratio of Heat Input to Electric
Output
Carbon Dioxide
(CO2)b
Carbon Monoxide
(CO)c
Methane (CH4)b
Nitrogen Oxides
(NOX)a
Nitrous Oxide
(N2O)b
Sulphur Dioxide
(SO2)a
Alabama
2.230
165.30922
1.45087E+03
1.72617E-03
4.02311E-01
2.80975E-03
1.13940E+00
Alaska
2.734
173.87708
3.71694E+02
8.56786E-04
7.29024E-01
1.12138E-03
2.38136E-01
Arizona
1.694
132.29777
8.26924E+02
8.56786E-04
2.74423E-01
1.94037E-03
2.27552E-01
Arkansas
2.207
162.03327
6.41833E+02
1.57497E-03
2.87149E-01
2.55776E-03
4.24991E-01
California
1.422
76.35472
2.91370E+03
8.44186E-04
6.56449E-02
4.66192E-04
3.04915E-02
Colorado
3.101
242.67192
1.51197E+03
1.60017E-03
4.74004E-01
3.64134E-03
5.83874E-01
Connecticut
1.720
118.69000
3.21421E+02
2.19236E-03
1.81563E-01
1.51197E-03
3.78750E-01
Delaware
2.736
230.57612
1.31290E+02
1.54977E-03
4.12517E-01
2.86015E-03
1.10866E+00
District of Columbia
4.844
172.11310
8.94585E+00
1.48677E-03
7.29528E-01
2.59556E-03
1.62487E+00
Florida
2.694
175.64105
6.12954E+03
1.88997E-03
4.73122E-01
2.26796E-03
1.00584E+00
Georgia
2.119
172.11310
1.05889E+03
1.62537E-03
4.00043E-01
2.84755E-03
1.11974E+00
Hawaii
2.950
209.40848
1.17682E+02
2.69635E-03
7.27512E-01
2.30576E-03
5.44437E-01
Idaho
0.213
3.52794
0
1.00798E-03
1.07098E-02
4.15793E-04
1.05838E-02
Illinois
1.694
146.66153
1.85292E+03
1.03318E-03
4.41749E-01
2.26796E-03
1.11811E+00
Indiana
3.281
261.57160
2.14058E+03
1.80177E-03
7.30284E-01
4.06973E-03
1.88846E+00
Iowa
3.033
237.12801
7.57877E+02
1.73877E-03
5.61447E-01
3.75474E-03
1.04566E+00
Kansas
2.826
212.18043
8.65983E+02
1.41118E-03
5.58801E-01
3.20035E-03
7.06596E-01
Kentucky
3.234
253.00374
1.50857E+03
1.76397E-03
8.41036E-01
4.04453E-03
1.79257E+00
Lousiana
2.624
148.42550
1.68116E+04
1.18438E-03
3.41958E-01
1.41118E-03
5.05755E-01
Maine
2.191
107.35019
4.92778E+02
7.11888E-03
1.79547E-01
3.40194E-03
4.04327E-01
Maryland
2.277
172.11310
4.89502E+02
1.48677E-03
5.37759E-01
2.59556E-03
1.38837E+00
Massachusetts
2.729
161.02529
7.89125E+02
2.19236E-03
2.89165E-01
2.00337E-03
8.01347E-01
Michigan
2.616
199.07665
1.69354E+03
1.83957E-03
4.91770E-01
3.14995E-03
9.76988E-01
Minnesota
2.331
163.04126
6.96264E+02
1.66317E-03
5.02354E-01
2.07897E-03
5.06889E-01
Mississippi
2.404
231.83610
2.17976E+03
1.58757E-03
4.66570E-01
3.62874E-03
8.98239E-01
Missouri
2.857
192.02077
1.29753E+03
1.97817E-03
6.41707E-01
3.11215E-03
9.07059E-01
Montana
1.936
180.68096
4.13147E+02
1.36078E-03
3.58212E-01
2.86015E-03
2.01219E-01
Nebraska
2.195
176.39703
4.68208E+02
1.19698E-03
3.94121E-01
2.75935E-03
5.29065E-01
Nevada
2.615
191.26478
3.82278E+02
1.13398E-03
4.01807E-01
2.45696E-03
4.02815E-01
New Hampshire
1.394
85.93055
2.63588E+02
2.16716E-03
2.03109E-01
1.77657E-03
8.71275E-01
New Jersey
1.451
88.95450
2.27250E+03
9.70184E-04
1.76649E-01
9.95383E-04
2.31206E-01
New Mexico
3.307
254.26372
8.56408E+02
1.65057E-03
6.57583E-01
3.72954E-03
5.70140E-01
New York
1.808
108.10618
1.93835E+03
1.02058E-03
1.69089E-01
1.12138E-03
4.68082E-01
North Carolina
1.969
156.48937
1.10286E+03
1.32298E-03
4.68712E-01
2.55776E-03
1.00131E+00
North Dakota
3.244
282.48725
9.01389E+02
1.85217E-03
6.44731E-01
4.27133E-03
1.52697E+00
Ohio
2.736
226.79619
1.58757E+03
1.63797E-03
7.67579E-01
3.62874E-03
2.33562E+00
Oklahoma
3.024
216.96835
1.67262E+03
1.38598E-03
5.11425E-01
2.80975E-03
5.11047E-01
Oregon
0.526
35.53140
1.86855E+02
4.15793E-04
5.26671E-02
4.28393E-04
7.50947E-02
Pennsylvania
1.827
159.26132
1.85885E+03
1.34818E-03
3.29232E-01
2.55776E-03
1.25834E+00
Rhode Island
2.561
132.54977
1.67955E+02
8.56786E-04
6.21170E-02
5.92190E-04
4.53592E-03
South Carolina
1.300
105.08223
8.38642E+02
1.14658E-03
2.54264E-01
1.82697E-03
6.04790E-01
South Dakota
1.192
100.54631
9.79004E+01
6.67789E-04
5.44941E-01
1.52457E-03
5.81354E-01
Tennessee
1.902
163.29325
9.09579E+02
1.32298E-03
5.10165E-01
2.67116E-03
1.18123E+00
Texas
2.749
184.46090
9.63405E+03
9.70184E-04
3.27720E-01
1.83957E-03
4.90888E-01
Utah
3.095
243.67990
5.13063E+02
1.68837E-03
5.26545E-01
3.88073E-03
2.13314E-01
Vermont
0.306
3.52794
1.38472E+02
1.20958E-03
1.94037E-02
4.91392E-04
2.14196E-03
Virginia
1.924
146.66153
9.12729E+02
1.72617E-03
3.65016E-01
2.41916E-03
7.86857E-01
Washington
0.414
30.99548
4.29653E+02
4.66192E-04
5.30451E-02
5.03992E-04
1.90383E-01
West Virginia
2.917
248.97181
1.27938E+03
1.72617E-03
7.77659E-01
3.98153E-03
1.86918E+00
Wisconsin
2.680
206.88852
1.00471E+03
1.73877E-03
4.97440E-01
3.27594E-03
9.25076E-01
Wyoming
3.534
270.39145
9.01389E+02
1.85217E-03
5.59431E-01
4.25873E-03
5.78708E-01
a Data based on 1999 data from eGRID version 2.01
(EPA 2003a).
b Data based on 1998-2000 average data in DOE (2002).
c Data based on tier emissions report for criteria air
pollutants in EPA (2003b).
d PM is the sum of all particulate matter including PM10
and PM2.5. PM10 and PM2.5 stand for particles smaller than 10
and 2.5 microns, respectively.
e No data.
U. S. State Average Criteria Pollutant Emission
Factors for Electricity Generation, in g/MJ
State
Particulate Matter
(PM)cd
Particulate Matter
(PM10)cd
Particulate Matter
(PM2.5)cd
Ammonia
(NH3)c
Volatile Organic Compounds
(NMVOC)a
Mercury (Hg)c
Lead (Pb)e
Alabama
7.91048E-03
7.86328E-03
4.72023E-05
3.55049E-05
4.66784E-03
5.14071E-06
0e
Alaska
8.96502E-03
8.85977E-03
1.05247E-04
6.51454E-06
2.82297E-03
3.27594E-07
0e
Arizona
1.70555E-02
1.69322E-02
1.23202E-04
1.80226E-04
2.27385E-03
1.88997E-06
0e
Arkansas
9.27803E-03
9.19307E-03
8.49561E-05
4.59383E-04
3.46429E-03
2.73415E-06
0e
California
7.16813E-03
7.07819E-03
8.99402E-05
4.02651E-03
2.62453E-03
1.38598E-07
0e
Colorado
7.29822E-03
7.23699E-03
6.12291E-05
9.56430E-05
4.36770E-03
1.62537E-06
0e
Connecticut
1.22734E-02
1.21694E-02
1.04033E-04
2.22944E-03
3.93896E-03
1.18438E-06
0e
Delaware
1.39283E-02
1.38287E-02
9.96131E-05
1.54469E-03
4.74441E-03
3.62874E-06
0e
District of Columbia
2.88269E-02
2.84861E-02
3.40760E-04
8.76496E-03
2.30080E-02
0
0e
Florida
4.33040E-02
4.29055E-02
3.98460E-04
1.58386E-03
3.39110E-03
1.71357E-06
0e
Georgia
2.05237E-02
2.03865E-02
1.37175E-04
7.51637E-05
2.16686E-03
3.20035E-06
0e
Hawaii
5.97339E-03
5.90409E-03
6.92999E-05
3.55697E-03
7.01715E-03
1.77657E-06
0e
Idaho
0
0
0
0
0
0
0
Illinois
1.53276E-01
1.52156E-01
1.12047E-03
5.93583E-03
2.77818E-02
4.62412E-06
0e
Indiana
2.18862E-02
2.17008E-02
1.85453E-04
5.75861E-04
4.87283E-03
4.86352E-06
0e
Iowa
2.34564E-02
2.32698E-02
1.86674E-04
9.09228E-05
4.78644E-03
6.19910E-06
0e
Kansas
2.41783E-02
2.39535E-02
2.24799E-04
4.19292E-04
5.39089E-03
4.93912E-06
0e
Kentucky
1.69397E-02
1.68139E-02
1.25825E-04
4.35029E-05
3.80922E-03
4.71232E-06
0e
Lousiana
1.79917E-02
1.77843E-02
2.07304E-04
1.66720E-03
1.02357E-02
1.41118E-06
0e
Maine
3.36399E-03
3.34131E-03
2.26813E-05
1.55132E-03
9.62614E-03
4.53592E-07
0e
Maryland
2.13382E-02
2.12038E-02
1.34391E-04
7.21581E-04
2.78881E-03
4.88872E-06
0e
Massachusetts
8.85244E-03
8.76617E-03
8.62772E-05
1.70282E-03
3.49171E-03
1.88997E-06
0e
Michigan
9.08755E-03
9.00520E-03
8.23449E-05
2.22140E-04
2.79017E-03
3.67914E-06
0e
Minnesota
4.04781E-02
4.01455E-02
3.32617E-04
6.74889E-05
4.13240E-03
3.30114E-06
0e
Mississippi
5.44446E-02
5.37910E-02
6.53601E-04
4.06289E-02
1.54329E-02
2.45696E-06
0e
Missouri
1.25537E-02
1.24368E-02
1.16929E-04
6.48638E-05
4.98085E-03
4.67452E-06
0e
Montana
3.67504E-03
3.64126E-03
3.37798E-05
4.01020E-05
3.14400E-03
3.77994E-06
0e
Nebraska
1.33751E-02
1.32829E-02
9.21636E-05
6.90470E-05
5.23031E-03
3.59094E-06
0e
Nevada
2.09146E-02
2.07657E-02
1.48886E-04
3.79659E-04
3.33440E-03
1.36078E-06
0e
New Hampshire
3.09503E-02
3.06487E-02
3.01568E-04
7.16019E-04
2.45937E-03
3.40194E-07
0e
New Jersey
3.45712E-02
3.41460E-02
4.25200E-04
1.24216E-04
1.52830E-02
1.28518E-06
0e
New Mexico
5.20754E-02
5.16748E-02
4.00653E-04
4.41665E-04
5.12951E-03
8.41666E-06
0e
New York
5.35802E-03
5.31301E-03
4.50068E-05
2.22325E-03
4.26008E-03
1.33558E-06
0e
North Carolina
3.40955E-02
3.38325E-02
2.62976E-04
3.00504E-05
1.73434E-03
3.33894E-06
0e
North Dakota
5.17162E-02
5.13979E-02
3.18277E-04
6.41672E-05
6.88995E-03
8.71905E-06
0e
Ohio
1.38722E-02
1.37957E-02
7.64501E-05
1.11541E-04
2.59201E-03
6.24949E-06
0e
Oklahoma
1.83971E-02
1.82479E-02
1.49160E-04
9.73713E-04
4.68484E-03
3.88073E-06
0e
Oregon
3.47911E-03
3.46199E-03
1.71186E-05
4.43277E-06
5.31933E-04
3.77994E-07
0e
Pennsylvania
2.21604E-02
2.20060E-02
1.54356E-04
1.47657E-04
1.51542E-03
6.56449E-06
0e
Rhode Island
1.03973E-03
1.02744E-03
1.22906E-05
0
2.25247E-03
0
0e
South Carolina
2.45530E-02
2.43803E-02
1.72632E-04
2.51344E-05
1.16735E-03
1.54977E-06
0e
South Dakota
4.67825E-03
4.63562E-03
4.26239E-05
8.82976E-05
4.63562E-03
1.22218E-06
0e
Tennessee
2.51650E-02
2.48944E-02
2.70575E-04
2.70034E-05
2.88396E-03
2.98615E-06
0e
Texas
1.73147E-02
1.71765E-02
1.38283E-04
1.26310E-03
4.32150E-03
3.52794E-06
0e
Utah
1.47314E-02
1.46364E-02
9.50155E-05
9.59315E-05
2.48737E-03
9.70184E-07
0e
Vermont
1.16247E-03
1.14873E-03
1.37415E-05
1.80704E-05
2.12073E-03
0
0e
Virginia
1.22315E-02
1.21362E-02
9.53635E-05
2.93259E-04
2.50975E-03
2.21756E-06
0e
Washington
5.37627E-04
5.32210E-04
5.41708E-06
6.46409E-06
6.87348E-04
5.92190E-07
0e
West Virginia
2.39677E-03
2.38177E-03
1.50018E-05
4.25792E-05
3.09497E-03
6.55189E-06
0e
Wisconsin
7.34187E-03
7.28252E-03
5.93472E-05
6.45613E-05
4.61829E-03
4.83832E-06
0e
Wyoming
5.08215E-02
5.06042E-02
2.17349E-04
5.19787E-05
4.78782E-03
5.27931E-06
0e
United States National Average Water Consumption
Factorsa
Generation Source
L/MJ
Percent of Total Generation
Thermoelectric
0.4960
89.4%
Hydroelectric
19.2095
8.6%
Total
2.1007
100%
a Based on data from Torcellini, Long, and
Judkoff (2004).
U.S. State Average Water Consumption Factors for
Electricity Generationa
State
Thermoelectric L/MJ
Thermoelectric %
Hydroelectric L/MJ
Hydroelectric %
Total
Alabama
0.1503
89.8%
38.9053
6.4%
2.6274
Alaska
0.3295
86.2%
–
13.8%
0.2839
Arizona
0.3313
88.3%
68.1928
11.7%
8.2533
Arkansas
0.3000
89.5%
–
5.7%
0.2684
California
0.0511
74.1%
21.9430
22.0%
4.8739
Colorado
0.5368
96.0%
18.8333
4.0%
1.2600
Connecticut
0.0860
90.8%
–
1.5%
0.0781
Delaware
0.0132
99.9%
–
0.0%
0.0132
District of Columbia
1.6959
100.0%
–
0.0%
1.6959
Florida
0.1506
95.7%
–
0.1%
0.1441
Georgia
0.6267
93.6%
49.8599
2.3%
1.7339
Hawaii
0.0440
92.4%
–
1.1%
0.0407
Idaho
0.0000
2.7%
8.9528
92.2%
8.2501
Illinois
1.1093
99.4%
–
0.1%
1.1032
Indiana
0.4350
99.6%
–
0.3%
0.4331
Iowa
0.1229
97.3%
–
2.5%
0.1196
Kansas
0.6099
100.0%
–
0.0%
0.6098
Kentucky
1.1521
97.2%
162.2884
2.8%
5.5990
Louisiana
1.6411
94.2%
–
0.9%
1.5461
Maine
0.3049
40.4%
–
28.7%
0.1231
Maryland
0.0343
95.3%
7.0617
2.7%
0.2259
Massachusetts
0.0000
92.4%
–
2.4%
0.0000
Michigan
0.5221
95.8%
–
1.4%
0.4999
Minnesota
0.4657
93.4%
–
2.4%
0.4351
Mississippi
0.4145
94.4%
–
0.0%
0.3912
Missouri
0.3213
97.4%
–
2.5%
0.3130
Montana
1.0051
55.8%
38.6619
44.1%
17.5997
Nebraska
0.2020
94.5%
2.2888
5.5%
0.3165
Nevada
0.5936
90.6%
77.1023
9.2%
7.6260
New Hampshire
0.1231
83.9%
–
8.6%
0.1033
New Jersey
0.0747
97.6%
–
0.0%
0.0729
New Mexico
0.6609
99.3%
71.5070
0.7%
1.1886
New York
0.8951
81.3%
5.8535
16.7%
1.7040
North Carolina
0.2445
95.5%
10.9089
3.1%
0.5751
North Dakota
0.3809
91.7%
60.7730
8.3%
5.3968
Ohio
0.9972
99.1%
–
0.3%
0.9884
Oklahoma
0.5378
93.7%
144.0133
5.8%
8.8254
Oregon
0.8633
18.4%
4.6351
80.7%
3.8990
Pennsylvania
0.5700
97.6%
–
1.0%
0.5563
Rhode Island
0.0000
98.2%
–
0.1%
0.0000
South Carolina
0.2754
97.2%
–
1.9%
0.2677
South Dakota
0.0143
36.7%
120.7558
63.2%
76.3811
Tennessee
0.0026
90.8%
45.5853
8.3%
3.7833
Texas
0.4595
99.0%
–
0.3%
0.4550
Utah
0.5959
96.6%
77.1150
3.4%
3.2090
Vermont
0.3642
71.5%
–
20.9%
0.2605
Virginia
0.0693
94.9%
–
0.9%
0.0657
Washington
0.3013
15.7%
3.3506
83.2%
2.8344
West Virginia
0.6180
99.0%
–
1.0%
0.6119
Wisconsin
0.5199
93.6%
–
3.3%
0.4867
Wyoming
0.5190
97.1%
144.0177
2.7%
4.3654
a Based on data from Torcellini, Long, and
Judkoff (2004).
Other
Energy-Related Pollutants and Sources of Other
Information[LINK]
EnergyPlus (with user entered-data) will also calculate
high- and low-level nuclear waste from electricity generation.
Few utilities now provide data on nuclear waste resulting from
electricity generation and no US national or state-level data
are yet available (this will be added as data become
available). Two Illinois utilities regularly report nuclear
waste in terms of pounds per kWh or MWh for high-level waste
and cubic feet per kWh or MWh for low-level waste. For these
two utilities, high level nuclear waste values range from
0.0042 to 0.01 lb/MWh (7000 to 16000 g/MJ); low-level nuclear
waste ranges from 0.0001 to 0.0002 ft3/MWh (0.01 to
0.02 m3/MJ) depending on relative proportion of
nuclear as compared with other electricity generation
sources.
IEA (2003) contains carbon dioxide (CO2)
emissions factors for electricity generation by country and
region. Carbon dioxide (CO2) is responsible for
over 60% of the anthropogenic greenhouse effect (UNEP 2002).
Because only limited greenhouse gas emissions factors and data
(other than CO2) is available for other countries,
an interim method for estimating emission factors would be to
compare the CO2 emission factor for the particular
country from IEA (2003) and match it to the state with the
closest CO2 emission factor in Table 102–using the
other emissions factors for that state. Since the Kyoto
Protocol (UNFCCC 1997) requires each country to report
emissions of the major greenhouse gases [carbon dioxide
(CO2), methane (CH4), and nitrous oxide
(N2O)] as well as ozone-depleting substances
[hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulphur
hexafluoride (SF6)] and all energy consumption in
their annual ‘national communication’, more complete emission
factors for a larger number of countries should become
available over the next few years. More information and other
resources for calculating emissions factors are available in
IPCC (2000, 1997).
Crawley, Drury B. 2003. “Impact of Climate Change on
Buildings,” in Proceedings of the CIBSE/ASHRAE
International Conference 2003, September 2003, Edinburgh,
Scotland. London, England: CIBSE.
Intergovernmental Panel on Climate Change. 2001.
Climate Change 2001: The Scientific Basis. Cambridge:
Cambridge University Press.
Intergovernmental Panel on Climate Change. 2000. Good
Practice Guidance and Uncertainty Management in National
Greenhouse Gas Inventories, Paris, France:
IPCC/OECD/IEA.
Intergovernmental Panel on Climate Change. 1997.
Revised 1996 IPCC Guidelines for National Greenhouse Gas
Inventories, J.T. Houghton, L.G. Meira Filho, B. Lim, K.
Treanton, I. Mamaty, Y. Bonduki, D.J. Griggs and B.A.
Callender (editors). Paris, France: IPCC/OECD/IEA.
International Energy Agency. 2003. CO2
Emissions from Fuel Combustion 1971-2001 (2003) – 2003
Edition. Paris, France: IEA.
Liesen, Richard J. 1997. Atmospheric Pollution
Prediction in a Building
Energy Simulation Program, April 1997, BLAST Support
Office, Department of Mechanical Engineering. Champaign,
Illinois: University of Illinois.
Stroot, Peter J., Robert J. Nemeth, & Donald F.
Fournier. 1996. Pollution Reduction Through Energy
Conservation, REEP Model. Champaign, Illinois: U S Army
Construction
Engineering Research Laboratory.
Torcellini Paul A, Nicholas Long, and Ronald D. Judkoff.
2004. “Consumptive Water Use for U.S. Power Production,” in
ASHRAE Transactions, Volume 110, Part 1. Atlanta,
Georgia: ASHRAE.
United Nations Environment Programme. 2002. Climate
Change Information Kit. Châtelaine, Switzerland:
UNEP.
United Nations Framework Convention on Climate Change.
1997. Kyoto Protocol to the United Nations Framework
Convention on Climate Change. Bonn, Germany: UNFCCC.
U.S. Department of Energy. 2004. Monthly Energy
Review. Washington, DC: Energy Information
Administration, U S Department of Energy.
U.S. Department of Energy. 2002. Updated State-level
Greenhouse Gas Emission Coefficients for Electricity
Generation 1998-2000. April 2002, Energy Information
Administration, Office of Integrated Analysis and Forecasting,
Energy Information Administration. Washington, DC: U.S.
Department of Energy.
U.S. Environmental Protection Agency. 2003a. eGRID
Emissions and Generation Resource Integrated Database,
May 2003, Washington, DC: U.S. Environmental Protection
Agency.
U.S. Environmental Protection Agency. 2003b.
AirData, Tier Emissions Report - Criteria Air
Pollutants, 1999 data, May 2003. Washington, DC: U.S.
Environmental Protection Agency.
U.S. Environmental Protection Agency. 1998a.
Compilation of Air Pollutant Emission Factors, AP-42,
Fifth Edition, Volume I: Stationary Point and Area
Sources, Chapter 1 External Combustion Sources,
Supplement D, July 1998. Research Triangle Park, North
Carolina: U. S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 1998b.
Compilation of Air Pollutant Emission Factors, AP-42,
Fifth Edition, Volume I: Stationary Point and Area
Sources, Chapter 1 External Combustion Sources,
Supplement E, September 1998. Research Triangle Park, North
Carolina: U. S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 1996. Compilation
of Air Pollutant Emission Factors, AP-42, Fifth Edition,
Volume I: Stationary Point and Area Sources, Chapter 1
External Combustion Sources, Supplement B, October 1996.
Research Triangle Park, North Carolina: U. S. Environmental
Protection Agency.
Environmental Impacts[LINK]
Typically when a new building technology is evaluated the energy performance of a baseline building is compared to the energy and life-cycle costs of alternatives to determine cost-effectiveness. But what if the lowest energy or life-cycle cost alternative is not the cleanest or lowest environmental impact? By calculating environmental impact, designers can compare alternatives not only in terms of their energy performance but also their environmental performance–working towards a more sustainable design (Liesen 1997; Stroot, Nemeth, and Fournier 1996). Environmental impacts are quantified, in part, by modeling the amount of emissions and in EnergyPlus this is done using the input objects “EnvironmentalImpactFactors,” “FuelFactors,” and “Output:EnvironmentalImpactFactors.”
Based on emissions factors entered by the user, EnergyPlus calculates the mass or volume of thirteen different pollutants: CO2 (carbon dioxide), CO (carbon monoxide), CH4 (methane), NOx (nitrogen oxides), N2O (nitrous oxide), SO2 (sulphur dioxide), PM (particulate matter), PM10 (particulate matter 10>PM10>2.5 microns), PM2.5 (particulate matter<2.5 microns), NH3 (ammonia), NMVOC (non-methane volatile organic compounds), Hg (mercury), and Pb (lead) as well as water consumed through evaporation in thermo- and hydro-electric generation and high- and low-level nuclear waste from nuclear electricity generation for on- and off-site energy production. Note that while these comprise the largest proportion of pollutants, more than one hundred other pollutants are emitted from fossil fuel combustion or electricity generation. Much of the information compiled here for fossil fuel combustion comes from AP-42 Compilation of Air Pollutant Emission Factors (EPA 1998a, 1998b, 1996). For more information on pollutants, see the U.S. Environmental Protection Agency (EPA) Clearinghouse for Inventories & Emission Factors (www.epa.gov/ttn/chief/efinformation.html).
EnergyPlus models energy performance of on-site fossil fuels and purchased electricity (generated from a variety of fuels including natural gas, oil, gasoline, diesel, coal, hydroelectric, nuclear, wind, solar power, and biomass). The energy performance calculated by EnergyPlus is converted into a mass or volume of pollutants emitted. From a baseline building, alternative energy and pollution saving technologies can be explored, and the energy savings and pollution reduction can be calculated. Figure 341 and Figure 342 illustrate a comparison of two buildings simulated using Chicago weather data in EnergyPlus and the calculated pollutant levels (based on U.S. national average pollutants) (Crawley 2003).
To calculate the mass or volume of each pollutant, consumption is multiplied by an emissions factor for each fuel (natural gas, electricity, fuel oil, diesel, or coal). In future versions, users will be able to schedule how the emissions factors by time of day, month, season and year. For electricity, the mix of generation fuel sources–whether utility, state or regional–is used to adjust the emission factors. If a user has emissions factors specific to the building site and equipment, these can be entered directly. There are no default emissions factors.
Types of Pollutants[LINK]
EPA categorizes pollutants as either Criteria Pollutants or Hazardous Pollutants. Criteria pollutants are the six substances for which EPA has set health-based standards, including carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter (PM10 and PM2.5), ozone (O3), and lead (Pb). Because ozone is created in atmospheric photochemical reactions of volatile organic compounds, ammonia, and other substances rather than direct building-related energy emissions, we do not calculated ozone emissions in EnergyPlus. But we do include ozone precursors: methane (CH4), non-methane volatile organic compounds (NMVOC), and ammonia (NH3). Hazardous pollutants are substances that are known or suspected to cause serious health problems such as cancer. We include typical hazardous substances associated with energy production and use including lead (Pb) and mercury (Hg). We also include CO2 (carbon dioxide) since it is largest greenhouse gas in terms of impact.
Carbon Equivalent[LINK]
The Intergovernmental Panel on Climate Change has studied the effects on the relative radiative forcing effects of various greenhouse gases. This effect, called Global Warming Potential (GWP), is described in terms of the Carbon Equivalent of a particular greenhouse gas. This equivalent is based on a factor of 1.0 for carbon. This group of gases includes carbon dioxide (CO2), carbon monoxide, nitrous oxide, methane, halocarbon emission, hydrofluorocarbons (HFC), perfluorocarbons (PFC), and chlorofluorocarbons (CFC). For building energy use, the main gases of concern are carbon dioxide, carbon monoxide, methane, and nitrous oxide. Although carbon monoxide has a relatively short life, CO emissions into the atmosphere may have a significant impact on climate forcing due to chemical impact on CH4 lifetime, and tropospheric O3 and CO2 photochemical production normally reacts to produce carbon dioxide, but it can’t be ignored since it is produced in incomplete combustion and the carbon remains to interact as CO2.Yetthere is no agreement on its carbon equivalent (IPCC 2001). The carbon equivalent of carbon dioxide, methane, and nitrous oxide are calculated and then multiplied by their GWP on a 100 year time frame. The Carbon Equivalents of the following gases have been determined and used in the program are shown in the following table.
The resulting carbon equivalents by fuel type are shown in the output of the program along with the individual gas pollutants.
Fossil Fuel Emissions Factors[LINK]
Emission factors for on-site fossil fuel consumption are based on Section 1.4 Natural Gas Combustion in EPA (1998a) Table 94 shows the greenhouse gas and precursors and criteria pollutant emissions factors for natural gas. Similar emissions factors are shown for residual fuel oil (No. 4 and No. 6 fuel oil) [Table 95], distillates (No. 1 and No. 2 fuel oil) [Table 96], residential oil furnace [Table 97], LPG (butane and propane) [Table 98], gasoline and diesel [Table 99], and coal [Table 100] in the indicated tables. Note that a zero for a pollutant in the table may mean that no data were available, not that there are no emissions of that pollutant.
Off-Site Electricity Generation Emissions[LINK]
While estimating emissions from on-site fossil fuel combustion can be fairly straight-forward, emissions from off-site electricity is more challenging. How the electricity is generated, i.e., from gas, oil, coal, nuclear, renewable sources (wind, PV) or hydroelectric, and the mix of generation determines the resulting level of emissions. While data are available at utility and even power plant level (from the sources cited), data are shown here for United States national- and state-level average emissions from electricity generation. Table 101 provides average greenhouse gas and precursors and criteria pollutant emissions factors for the entire United States from electricity generation. Table 102 provides average electricity emissions factors by state, for greenhouse gas and precursors, and Table 103 for criteria pollutant emission factors. These two tables also include a ratio of heat input to electric output (efficiency of electricity generation) including distribution and transmission losses to allow calculation of source energy.
As mentioned in the introduction to this section, EnergyPlus also calculates water consumed through evaporation in thermo-electric and hydro-electric generation. Torcellini, Long, and Judkoff (2004) provide data on average water consumption by generator type by state. These data are summarized in units suitable for EnergyPlus in Table 101, for national and state average water consumption for thermal-electric, hydro-electric, and Table 102 for weighted total electricity generation.
a Based on data from Torcellini, Long, and Judkoff (2004).
Other Energy-Related Pollutants and Sources of Other Information[LINK]
EnergyPlus (with user entered-data) will also calculate high- and low-level nuclear waste from electricity generation. Few utilities now provide data on nuclear waste resulting from electricity generation and no US national or state-level data are yet available (this will be added as data become available). Two Illinois utilities regularly report nuclear waste in terms of pounds per kWh or MWh for high-level waste and cubic feet per kWh or MWh for low-level waste. For these two utilities, high level nuclear waste values range from 0.0042 to 0.01 lb/MWh (7000 to 16000 g/MJ); low-level nuclear waste ranges from 0.0001 to 0.0002 ft3/MWh (0.01 to 0.02 m3/MJ) depending on relative proportion of nuclear as compared with other electricity generation sources.
IEA (2003) contains carbon dioxide (CO2) emissions factors for electricity generation by country and region. Carbon dioxide (CO2) is responsible for over 60% of the anthropogenic greenhouse effect (UNEP 2002). Because only limited greenhouse gas emissions factors and data (other than CO2) is available for other countries, an interim method for estimating emission factors would be to compare the CO2 emission factor for the particular country from IEA (2003) and match it to the state with the closest CO2 emission factor in Table 102–using the other emissions factors for that state. Since the Kyoto Protocol (UNFCCC 1997) requires each country to report emissions of the major greenhouse gases [carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)] as well as ozone-depleting substances [hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulphur hexafluoride (SF6)] and all energy consumption in their annual ‘national communication’, more complete emission factors for a larger number of countries should become available over the next few years. More information and other resources for calculating emissions factors are available in IPCC (2000, 1997).
References[LINK]
Crawley, Drury B. 2003. “Impact of Climate Change on Buildings,” in Proceedings of the CIBSE/ASHRAE International Conference 2003, September 2003, Edinburgh, Scotland. London, England: CIBSE.
Intergovernmental Panel on Climate Change. 2001. Climate Change 2001: The Scientific Basis. Cambridge: Cambridge University Press.
Intergovernmental Panel on Climate Change. 2000. Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories, Paris, France: IPCC/OECD/IEA.
Intergovernmental Panel on Climate Change. 1997. Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, J.T. Houghton, L.G. Meira Filho, B. Lim, K. Treanton, I. Mamaty, Y. Bonduki, D.J. Griggs and B.A. Callender (editors). Paris, France: IPCC/OECD/IEA.
International Energy Agency. 2003. CO2 Emissions from Fuel Combustion 1971-2001 (2003) – 2003 Edition. Paris, France: IEA.
Liesen, Richard J. 1997. Atmospheric Pollution Prediction in a Building Energy Simulation Program, April 1997, BLAST Support Office, Department of Mechanical Engineering. Champaign, Illinois: University of Illinois.
Stroot, Peter J., Robert J. Nemeth, & Donald F. Fournier. 1996. Pollution Reduction Through Energy Conservation, REEP Model. Champaign, Illinois: U S Army Construction Engineering Research Laboratory.
Torcellini Paul A, Nicholas Long, and Ronald D. Judkoff. 2004. “Consumptive Water Use for U.S. Power Production,” in ASHRAE Transactions, Volume 110, Part 1. Atlanta, Georgia: ASHRAE.
United Nations Environment Programme. 2002. Climate Change Information Kit. Châtelaine, Switzerland: UNEP.
United Nations Framework Convention on Climate Change. 1997. Kyoto Protocol to the United Nations Framework Convention on Climate Change. Bonn, Germany: UNFCCC.
U.S. Department of Energy. 2004. Monthly Energy Review. Washington, DC: Energy Information Administration, U S Department of Energy.
U.S. Department of Energy. 2002. Updated State-level Greenhouse Gas Emission Coefficients for Electricity Generation 1998-2000. April 2002, Energy Information Administration, Office of Integrated Analysis and Forecasting, Energy Information Administration. Washington, DC: U.S. Department of Energy.
U.S. Environmental Protection Agency. 2003a. eGRID Emissions and Generation Resource Integrated Database, May 2003, Washington, DC: U.S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 2003b. AirData, Tier Emissions Report - Criteria Air Pollutants, 1999 data, May 2003. Washington, DC: U.S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 1998a. Compilation of Air Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Chapter 1 External Combustion Sources, Supplement D, July 1998. Research Triangle Park, North Carolina: U. S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 1998b. Compilation of Air Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Chapter 1 External Combustion Sources, Supplement E, September 1998. Research Triangle Park, North Carolina: U. S. Environmental Protection Agency.
U.S. Environmental Protection Agency. 1996. Compilation of Air Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Chapter 1 External Combustion Sources, Supplement B, October 1996. Research Triangle Park, North Carolina: U. S. Environmental Protection Agency.
Documentation content copyright © 1996-2026 The Board of Trustees of the University of Illinois and the Regents of the University of California through the Ernest Orlando Lawrence Berkeley National Laboratory. All rights reserved. EnergyPlus is a trademark of the US Department of Energy.
This documentation is made available under the EnergyPlus Open Source License v1.0.