The Impact of Air Quality Regulations on Distributed ... - NREL

Microturbine
Small Turbine
Fuel Cell
Lean Burn Gas Engine
Rich Burn Gas Engine/3-way
Catalyst
Diesel Engine
U.S. Average All Generation
0.4
0.5
0.04
Carbon Dioxide—Although they are not
currently regulated at the Federal level, CO2
emissions are starting to be regulated at the
state and regional levels. Figure 2-6 shows
that the CO2 emissions <strong>of</strong> DG technologies
are comparable to or lower than the average
grid emissions. DG technologies generally
use relatively low carbon fuels (gas or diesel).
However, the grid average includes a large
amount <strong>of</strong> nuclear- and hydro-generated
power that creates no CO2 emissions.
Overall <strong>Air</strong> Emissions—<strong>The</strong> comparisons in
Figures 2-3 to 2-6 show that DG technologies
generally have lower air emissions than the
average <strong>of</strong> central station generators. <strong>The</strong>
1.1
3.4
2.2
Line Losses
0 2 4 6 8 10 12 14 16 18 20
lb/MWh
Figure 2-5
NOx Emissions Comparison
15
21.8
primary exception is the NOx and particulate
emissions from diesel engines. To the extent
that generation from DG installations using
technologies other than diesels displaces
existing central station generation, air
emissions will be reduced and the
environment will benefit. To the extent that
these installations apply CHP, the
environmental benefit will be even greater.
<strong>The</strong> simple comparisons in Figures 2-3 to 2-6
indicate that DG technologies can provide
significant environmental benefits in addition
to the economic and operational benefits that
they <strong>of</strong>fer to owners and operators.