Environmental Engineering Reference
In-Depth Information
TABLE 2.2
Estimated Emission Savings from Wind on July 2, 2008 (Method A)
SO
2
(lb)
NO
X
(lb)
CO
2
(ton)
Estimated stable day (July 29) emission rates
(per MWh)
2.01
3.82
1.08
Estimated stable emission rates, no wind generated
(3:00-7:00 a.m.); total generation = 3,360 MWh
6,754
12,829
3,628
Stable rates, actual generation (3:00-7:00 a.m.); total
generation = 2,997 MWh
6,025
11,443
3,236
Saved [additional] emissions
730
1,386
392
TABLE 2.3
Estimated Emission Savings from Wind on July 2, 2008 (Method B)
SO
2
(lb)
NO
X
(lb)
CO
2
(ton)
Estimated stable day (July 29) emission rates (per
MWh)
2.01
3.82
1.08
Actual July 2 emission rates (per MWh)
4.37
7.89
1.13
Stable emission rates, no wind generated (3:00-7:00
a.m.); total generation = 3,360 MWh
6,754
12,829
3,628
Actual July 2 emissions (3:00-7:00 a.m.); total
generation = 2,997 MWh
13,103
23,655
3,383
Saved [additional] emissions
[6,348]
[10,826]
246
TABLE 2.4
Estimated Emission Savings from Wind on July 2, 2008 (Method C)
SO
2
(lb)
NO
X
(lb)
CO
2
(ton)
Estimated stable day (July 29) emission rates
(per MWh)
2.01
3.82
1.08
Actual July 2 emission rates (per MWh)
4.37
7.89
1.13
Estimated stable emissions, no wind generated
(3:00-7:00 a.m.); total generation= 3,360 MWh
33,787
64,175
18,151
Actual July 2 emissions (3:00-7:00 a.m.); total
generation = 2,997 MWh
71,897
129,799
18,561
Saved [additional] emissions
[38,109]
[65,624]
[410]
Method C (Table 2.4) provides the most accurate analysis because it captures
the total impact of cycling the plant. The net result is that cycling Cherokee
on July 2 resulted in greater emissions, even netting the emission avoided by
using wind. Table 2.5 summarizes the results of the three calculation meth-
ods. If wind generation had not caused PSCO to cycle Cherokee on July 2,
38,110 lb of SO
2
or 53% of the day's total SO
2
emissions, 65,624 lb or 51% of
