Environmental Engineering Reference
In-Depth Information
emissions were below average. This example indicates that impacts of
cycling were relatively minimal.
1600
140
120
100
80
60
40
20
0
Wind
Event
Cherokee Unit 2
December 23, 2008
1400
1200
1000
800
600
Actual NO
x
Actual SO
2
Normal SO
2
Normal NO
x
400
EXAMPLE 2.2
Cherokee Unit 2 also provided Example 2.3. On June 15, 2008, generation
fell by 23% between 3:00 and 4:00 a.m., with a further drop of 7% between
4:00 and 5:00 a.m. Between 5:00 and 6:00 a.m., generation rose sharply (14%),
followed by another 20% rise before 7:00 a.m. The event produced 3,739 lb of
SO
2
and 1,094 lb of NO
X
—more than the levels expected had the plant's aver-
age emission rate for June 2008 been achieved.
1600
1400
1200
1000
800
600
400
200
0
120
Wind
Event
Cherokee Unit 2
June 15, 2008
100
80
60
40
Actual NO
x
Normal NO
x
Actual SO
2
Normal SO
2
20
0
EXAMPLE 2.3
Example 2.4 depicts Cherokee Unit 2 on April 1, 2008. Generation fell by 6%
between midnight and 1:00 a.m., and dropped another 22% between 1:00 and
2:00 a.m. Between 2:00 and 3:00 a.m., it rose by 14%, and rose another 20%
before 4:00 a.m. This cycling incident generated 1,412 lb of SO
2
and 4,644 lb
of NO
X
—more than the levels expected had the plant's average emission rate
for April 2008 been achieved.
