These optional spreadsheets are provided to assist reporters in calculating emissions and in keeping records of these calculations.
Reporters are required to keep records of these calculations under 40 CFR 98.3(g) and additional subpartspecific provisions, but are not required to use these spreadsheets or to submit any spreadsheets to EPA.
Spreadsheets may include inputs to emission equations, reporting of some of which EPA deferred until 2015.
(See 76 FR 53057, published August 25, 2011, http://www.gpo.gov/fdsys/pkg/FR20110825/pdf/201121727.pdf).
The data elements deferred until 2013 that will be collected for the first time in RY2012 enable emissions calculations to be executed within eGGRT for certain subpart equations. As a result, affected Optional Calculation Spreadsheets will become obsolete. The Optional Calculation Spreadsheets associated with the equations below will become obsolete for this subpart beginning RY2012:
 Equation C11
Copies of these spreadsheets can be downloaded at the Calculation Spreadsheet Archive.
Overview
This help page provides guidance for working with the supplemental subpart C calculation spreadsheets. The guidance provides stepbystep instructions for the following tasks:
 Selecting the Appropriate Calculation Spreadsheet
 Downloading a Calculation Spreadsheet
 General Information on Using a Calculation Spreadsheet
 Using the Equation C1, C8 Calculation Spreadsheet
 Using the Equation C1a, C8a Calculation Spreadsheet
 Using the Equation C1b, C8b Calculation Spreadsheet
 Using the Equation C2a, C2b, C9a Calculation Spreadsheet
 Using the Equation C2c, C9b Calculation Spreadsheet
 Using the Equation C3, C8 Calculation Spreadsheet
 Using the Equation C4, C8 Calculation Spreadsheet
 Using the Equation C5, C8 Calculation Spreadsheet
 Using the Equation C10 Calculation Spreadsheet
Specific information on each of the calculation spreadsheets is provided below:
Calculation Spreadsheet 
Instructions 

Equation C10 Calculation Spreadsheet.xls  C10 Help 
Selecting the Appropriate Calculation Spreadsheet
To calculate emissions for stationary combustion units reporting under subpart C, users may use the spreadsheets described in the table below. The equations for calculating CO_{2} mass emissions and CH_{4}/N_{2}O mass emissions are combined onto one spreadsheet as appropriate. The table below describes the equation inputs, outputs, and the Tier and eGGRT configuration types in which each equation may apply. Note that some Tiers and Configurations only allow the use of a given equation for certain situations. Ultimately, the user should refer to 40 CFR 98.33(b) to determine which Tier is allowed and to 40 CFR 98.33(a) to determine which equation within a Tier is appropriate. If a configuration combusts multiple fuel types, it is possible that different tiers and different equations may be used for that given configuration. The spreadsheets are designed to account for one type of fuel, so each additional fuel combusted in a configuration will need a new spreadsheet.
Calculation Spreadsheet 
Tier 
Basis for Calculations 
Configuration 
Output(s) 

1 
EF, Fuel Use, Default HHV 
1, 3, 4 
CO_{2}  
1 
EF, Natural Gas Billing Records 
1, 3, 4 
CO_{2}  
1 
EF, Natural Gas Billing Records 
1, 3, 4 
CO_{2}  
2 
EF, Fuel Use, Measured HHV 
1, 3, 4 
CO_{2}  
2 
EF, Steam Use, Boiler Max Rated Heat Input Capacity 
1, 3, 4 
CO_{2}  
3 
Fuel Use, Measured Fuel Carbon Content 
1, 3, 4 
CO_{2}  
3 
Fuel Use, Measured Fuel Carbon Content 
1, 3, 4 
CO_{2}  
3 
Fuel Use, Measured Fuel Carbon Content 
1, 3, 4 
CO_{2}  
Equation C10 Calculation Spreadsheet.xls  4  EF, Heat Input from Combustion  2, 5, 6  CH_{4} N_{2}O 
Tier 1 Calculation Methodology
To calculate annual CO_{2}, CH_{4}, and N_{2}O mass emissions for each type of fuel using Tier 1 in each reporting configuration, use Equation C1, C8 Calculation Spreadsheet, Equation C1a, C8a Calculation Spreadsheet (natural gas billed in therms only), or Equation C1b, C8b Calculation Spreadsheet (natural gas billed in mmBtu only).
Equation C1, C8 Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for a stationary fuel combustion configuration that uses the Equation C1, Tier 1 calculation methodology for any given fuel. Use Equation C1 on this spreadsheet except when natural gas billing records are used to quantify fuel usage and gas consumption is expressed in units of therms or million Btu. In that case, use Equation C1a or C1b, as applicable. This spreadsheet performs the calculation using Equations C1 and C8, which are provided below:
(Equation C1)
(Equation C8)
Equation C1a, C8a Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from natural gas usage for a configuration that fires natural gas and only if billing records are used to quantify fuel usage and gas consumption is expressed in units of therms. This spreadsheet performs the calculations using Equations C1a and C8a, which are provided below:
(Equation C1a)
(Equation C8a)
Equations C1b, C8b Calculation Spreadsheet
Use the spreadsheet below to calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from natural gas usage for a configuration that fires natural gas and only if billing records are used to quantify fuel usage and gas consumption is expressed in units of mmBtu. This spreadsheet performs the calculations using Equations C1b and C8b, which are provided below.
(Equation C1b)
(Equation C8b)
Tier 2 Calculation Methodology
To calculate annual CO_{2}, CH_{4}, and N_{2}O mass emissions for each type of fuel in each reporting configuration, use Equation C2a, C2b, C9a Calculation Spreadsheet or Equation C2c, C9b Calculation Spreadsheet.
Equation C2a, C2b, C9a Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for a stationary fuel combustion configuration that uses the Tier 2 calculation methodology. This spreadsheet performs the calculation using Equations C2a, C2b, and C9a, which are provided below (although included, Equation C2b is not always required, see 40 CFR 98.33(a)(2)(ii)):
(Equation C2a)
(Equation C2b)
(Equation C9a)
Equation C2c, C9b Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions for a stationary fuel combustion configuration that uses the Equation C2c, Tier 2 calculation methodology. This worksheet should be used for MSW when the use of Tier 2 is allowed or (optionally) for solid fuels using Tier 2 that generate steam. This spreadsheet performs the calculations using Equations C2c and C9b, which are provided below:
(Equation C2c)
(Equation C9b)
Tier 3 Calculation Methodology
To calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for each type of fuel using Tier 3 in each type of reporting configuration, use Equation C3, C8 Calculation Spreadsheet, Equation C4, C8 Calculation Spreadsheet, or Equation C5, C8 Calculation Spreadsheet.
Equation C3, C8 Calculation Spreadsheet
Use the spreadsheet below to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for solid fuels using Tier 3 Calculation methodology at each configuration. This spreadsheet performs the calculation using Equations C3 and C8, which are provided below:
(Equation C3)
(Equation C8)
Equation C4, C8 Calculation Spreadsheet
Use the spreadsheet below to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for liquid fuels using the Tier 3 calculation methodology at each configuration. This spreadsheet performs the calculations using Equations C4 and C8, which are provided below:
(Equation C4)
(Equation C8)
Equations C5, C8 Calculation Spreadsheet
Use the spreadsheet below to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for gaseous fuels using the Tier 3 calculation methodology at each configuration. This spreadsheet performs the calculations using Equations C5 and C8, which are provided below:
(Equation C5)
(Equation C8)
Downloading a Calculation Spreadsheet
Calculation spreadsheets for subpart C may be downloaded by clicking one of the links in the first column of the table below. Users may also jump to instructions for each calculation spreadsheet by clicking one of the links in the second column.
Calculation Spreadsheet 
Instructions 

Using a Calculation Spreadsheet to Make Calculations
The guidance provided in this section applies to each of the calculation spreadsheets for subpart C. Additional guidance is provided for each individual calculation spreadsheet in the sections below.
Color coding
The calculation spreadsheets contain green input cells, gray informational cells, and redbordered results cells filled with yellow or white. Users should use green input cells to enter all data specific to their facility, unit, or process. Gray informational cells contain parameter names, column and row headings, equation constants and subtotals. Calculation results are displayed in redbordered results cells filled with yellow or white. For redbordered, yellowfilled results cells, the values in these cells should be entered in the appropriate and separate calculation spreadsheet (as directed below cell) where additional calculations will be made. For redbordered, white filled results cells, the values in these cells should be entered in eGGRT for the appropriate process units. All cells that are not green input cells are locked and cannot be modified.

Green input cell (data entry) 

Gray informational cells (locked) 

Redbordered, yellowfilled results cells (enter in appropriate and separate calculation spreadsheet) 

Redbordered, white filled results cells (enter in eGGRT) 
Stop and Warning Messages
The calculation spreadsheets will display a stop message if the user enters a value that is invalid or a warning message if the user enters a value outside the EPA estimated range for a particular data element. For invalid data entries, the stop messages will not allow a user to proceed and the user must reenter valid data before moving forward. For data entries that are outside the EPA estimated range for a particular data element, the warning messages will allow a user to proceed if the user deems the entered value to be accurate.
Multiple Configuration Types and Multiple Fuels
Users with multiple configuration types and multiple fuels should use separate calculation spreadsheets for each configuration type and for each fuel. Users should not aggregate data for multiple configuration types or fuels when using these calculation spreadsheets.
Using the Equation C1, C8 Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for a stationary fuel combustion configuration that uses the Equation C1, Tier 1 calculation methodology for any given fuel. Use Equation C1 on this spreadsheet except when natural gas billing records are used to quantify fuel usage and gas consumption is expressed in units of therms or million Btu. In that case, use Equation C1a or C1b, as applicable. Use a separate spreadsheet for each configuration and for each fuel. The Equation C1, C8 Calculation Spreadsheet performs the calculations using Equations C1 and C8 provided below.
(Equation C1)
(Equation C8)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C1a, C8a Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from natural gas usage for a configuration that fires natural gas and if billing records are used to quantify fuel usage and gas consumption is expressed in units of therms. Use a separate spreadsheet for each configuration and for each fuel. The Equation C1a, C8a Calculation Spreadsheet performs the calculations using Equations C1a and C8a provided below.
(Equation C1a)
(Equation C8a)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C1b, C8b Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2} , CH_{4}, and N_{2}O emissions from natural gas usage for a configuration that fires natural gas and if billing records are used to quantify fuel usage and gas consumption is expressed in units of mmBtu. Use a separate spreadsheet for each configuration and for each fuel. The Equation C1b, C8b Calculation Spreadsheet performs the calculations using Equations C1b and C8b provided below.
(Equation C1b)
(Equation C8b)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C2a, C2b, C9a Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for a stationary fuel combustion configuration that uses the Equation C2a, Tier 2 calculation methodology. This spreadsheet performs the calculation using Equations C2a, C2b, and C9a, which are provided below (although included, Equation C2b is not always required, see 40 CFR 98.33(a)(2)(ii)). Use a separate spreadsheet for each configuration and for each fuel. The Equation C2a, C2b, C9a Calculation Spreadsheet performs the calculations using Equations C2a, C2b, and C9a provided below.
(Equation C2a)
(Equation C2b)
(Equation C9a)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Input for Weighted Annual Average HHV (only if required or elected) table.
The calculation spreadsheet will calculate the weighted annual average high heat value of the fuel (HHV_{annual}). The calculated value will be displayed in a redbordered cell with yellow fill above the Fuel Input Data table. This value should be entered in the Fuel Input Data table (shown below) along with the mass or volume of fuel combusted during the reporting year. Alternatively, you may enter an annual average HHV consistent with Section 98.33(a)(2)(ii).
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells with white fill at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C2c, C9b Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions for a stationary fuel combustion configuration that uses the Equation C2c, Tier 2 calculation methodology. This spreadsheet should be used for MSW when the use of Tier 2 is allowed or (optionally) for solid fuels using Tier 2 in units that generate steam. Use a separate spreadsheet for each configuration and for each fuel. The Equation C2c, C9b Calculation Spreadsheet performs the calculations using Equations C2c and C9b provided below.
(Equation C2c)
(Equation C9b)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C3, C8 Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for solid fuels using Tier 3 Calculation methodology at each configuration. Use a separate spreadsheet for each configuration and for each fuel. The Equation C3, C8 Calculation Spreadsheet performs the calculations using Equations C3 and C8 provided below.
(Equation C3)
(Equation C8)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C4, C8 Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for liquid fuels using the Tier 3 calculation methodology at each configuration. Use a separate spreadsheet for each configuration and for each fuel. The Equation C4, C8 Calculation Spreadsheet performs the calculations using Equations C4 and C8 provided below.
(Equation C4)
(Equation C8)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C5, C8 Calculation Spreadsheet
Use this spreadsheet to calculate the annual CO_{2}, CH_{4}, and N_{2}O mass emissions for gaseous fuels using the Tier 3 calculation methodology at each configuration. Use a separate spreadsheet for each configuration and for each fuel. The Equation C5, C8 Calculation Spreadsheet performs the calculations using Equations C5 and C8 provided below.
(Equation C5)
(Equation C8)
Begin by entering the facility name, your name, the configuration identifier, reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Fuel Input Data table.
The calculation spreadsheet will calculate the annual CO_{2}, CH_{4}, and N_{2}O emissions from fuel combustion. The calculation spreadsheet will also convert CH_{4} and N_{2}O emissions to units of carbon dioxide equivalent (CO_{2}e). The calculated values will be displayed in redbordered cells at the bottom of the spreadsheet. These values should be entered in eGGRT for this fuel and configuration type combination.
Using the Equation C10 Calculation Spreadsheet
Use the Equation C10 Calculation Spreadsheet to calculate annual CH_{4}, and N_{2}O emissions using an emission factor and the annual heat input from a fuel combusted in units that use Tier 4 (CEMS, Configuration Types 2 and 5), or, to check eGGRT’s calculations of annual CH_{4}, and N_{2}O emissions for units that report under 40 CFR Part 75 (Configuration Type 6). You can also use the Equation C10 Calculation Spreadsheet to calculate annual CH_{4} and N_{2}O emissions from fuel combustion in units that use Tier 4 to calculate combined process and combustion CO_{2} emissions. Use a separate spreadsheet for each configuration and for each fuel. The Equation C10 Calculation Spreadsheet performs the calculations using Equation C10 provided below.
(Equation C10)
Click to download the Equation C10 Calculation Spreadsheet.
See Also