NOx Emissions Impacts from Widespread Deployment of CHP in ...

NOx Emissions Report
filter is analytically included in the process of establishing this potential,
consideration of factors generally known to be supportive of CHP development
are considered. The technical potential results used here provide a breakdown of
the data into project size categories. For this study, the statewide technical
potential obtained from Elliott 2007 was reduced to estimate the CHP technical
potential solely in the HGB industrial sector. The technical potential does not
consider any CHP systems already developed and operating.
• Create CHP Prototypes
Ten prototypical CHP configurations were created to meet the technical potential
for project development. The prime mover technology used in each prototype was
chosen based upon project size and needs, while operating strategies for the
project were selected consistent with standard industry practice and economic
drivers. While economic criteria are not explicitly modeled, the implementation
and operation of proposed CHP projects is consistent with industry standards for
such developments. NOx emissions produced by the prototypes were determined
by modeling six representative projects using the EPA CHP Emission Calculator 14
v1.1 and extending the results to all ten prototypes by using an appropriate
multiplier. The results produced by the Emission Calculator are provided in
Appendix B.
• Characterize Potential CHP Projects
The performance of the ten industrial CHP prototypes were modeled using
detailed assumptions of operating hours, thermal energy utilization, and capacity
factors. The model inputs and results for each of the six projects are provided in
Appendix B.
A detailed description of the methodology and results is provided below.
3.2 Industrial CHP Potential (HGB Only)
While Texas industry has aggressively adopted CHP, significant potential remains for
additional development. A number of recent studies have examined the potential for CHP
(Onsite Energy 2000, Elliott 2001, Elliott 2007). In the oldest study completed in 2000,
Onsite Energy projected the potential at over 20,000 MW, with about two-thirds of that
potential (13,400 MW) existing in industry. Even with over 14 GW of capacity already
implemented in the chemical and petroleum industries (SIC 28 & 29), CHP potential in
these industries was thought to be about 7,500 MW or 56% of the remaining potential.
14 The Combined Heat and Power (CHP) Emissions Calculator compares the anticipated emissions from a
CHP system to the emissions from systems using separate heat and power (SHP). While the results
generated by the CHP Emissions Calculator are not designed for use in developing emission inventories or
preparing air permit applications, the emissions results are thought to provide sufficient accuracy for this
report. At the time of the analysis, the EPA had issued an updated version of the eGRID database, which
was not yet reflected in the current version of the Calculator. As a result, the NOx emissions values used to
determine the amount of NOx saved by off-setting electricity that would otherwise be supplied from the
utility grid were reduced from 2.31 lbs per MWh to 1.07 lbs per MWh.
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