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

NOx Emissions Report
system under the current air quality regulations. In addition, CHP projects are currently
restricted from receiving TERP funding promoting NOx reductions, particularly in the
HGB non-attainment region. The scientific basis for these restrictions should be further
analyzed and quantified.
Potential opportunities to develop CHP in the commercial and institutional building
sector are numerous, but the NOx impacts are highly dependent on the CHP operating
strategy employed for such systems. Current market dynamics favor the development of
small CHP systems designed and operated to serve facility thermal loads (Case 3). While
such systems have a potentially beneficial NOx impact, the impact is anticipated to be
only about one-third of the possible NOx reductions. Without additional incentives, a
purely market based approach would under develop CHP capacity in the commercial
market resulting in the realization of substantially lower NOx savings.
This study did not evaluate the impact of CHP development time, which can take one to
three years for a single system. Widespread implementation of CHP of a magnitude
similar to what is suggested here could conceivably take 10-15 years or longer.
Additional study is needed to better quantify and forecast NOx impacts into the future.
4.3 Conclusions
In HGB today, the potential for additional CHP systems in both commercial and
industrial sectors is large and growing. In the commercial sector, office buildings
represent a large opportunity for CHP, although other building types like hospitals and
hotel may be a better fit for CHP. In the industrial sector, large projects over 20 MW
represent the best opportunities for NOx reductions, although many smaller projects are
possible. Potential NOx savings anticipated from widespread adoption of CHP in existing
structures in HGB is estimated to be in the rage of 13 - 15 tons per day.
Implementation of CHP reduces total NOx emissions, but shifts some of those emissions
to those facilities adopting its use. Thus, the geographical distribution of NOx emissions
is changed through CHP implementation. While total savings are achieved, NOx
emissions at facilities adopting CHP is anticipated to increase. For HGB, this could mean
that local NOx emissions could increase by about 11.8 tons per day. This study suggests
that widespread adoption of CHP would reduce NOx concentrations in HGB if more than
half of the NOx savings from decreased use of grid electricity actually lowered NOx
concentrations in the eight-county region. Further studies of the NOx savings from CHP
and the potential impacts on ozone formation are warranted.
In recent years, commercial real estate owners and developers are increasingly looking at
CHP for economic and environmental reasons, and a few CHP projects are currently
under construction in HGB. However, the adoption rate for CHP, especially among
industrial facilities, has slowed due to volatile natural gas prices and uncertain economic
conditions. If additional NOx savings are to be realized from CHP, a number of
regulatory and market barriers will need to be addressed and incentive provided to value
the NOx benefits.
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