The rearchetected system uses updated carbon emissions factors from those in the legacy system. At present this is used only by the Home Energy Scoring tool.
To arrive at the carbon emissions (as CO2) for
energy consumed in the user’s house, we multiply the annual energy for each
fuel type by the emissions factor for the respective fuel:
emissions = sum (site energy[resource] * carbon_factor[resource])
where: resource = electric, natural gas, fuel oil, lpg
Table 33 presents the
emissions factors for fossil fuels. Natural
gas and fuel oil emission factors are derived from U.S. DOE (1994), while the
LPG emission factor is from U.S. DOE (1996).
Table 33. Direct Carbon Emissions
(as CO2) from Residential Fuel Combustion
| Pellet Wood
| Cord Wood
Table 34. contains
the state level emissions factors for electricity.
Table 34. State Level
Electricity Carbon Emissions Factors (as CO2)
Notes on Tables 34:
- Used data from eGRID (Emissions & Generation Resource Integrated Database),
which contains emissions and resource mix data for virtually every power plant
and company that generates electricity in the United States. eGrid version is eGrid 9th ed. year 2010 Data.
state-specific level emission factors updated to eGRID 9th edition,
year 2010 data. The state specific emissions only used for HI and AK, as
before included because used in past version.
- States are mapped to the eGrid sub-regions by visual inspection and judgment.
are 3 difficult cases in which the state contains (entirely, not just
overlapping) more than one region so mapping is particularly
- Hawaii- there are
two regions, Hawaii misc and Oahu. The emission factors are fairly
close, and because it seems unlikely that Hawaii imports much
electricity the state emission factor was used rather than chosing a
- Alaska- there are two regions
Alaska misc covers most of the area, the other proably includes
Anchorage, so may represent more people. The two regions have very
different emission rates, so used the state emission factor here also.
there are 3 regions, Upstate, City and Long Island. Upstate and City
are fairly similar (<15% difference), but Long Island much (2.5X)
higher. Because is represents most of the area, used the emission rate