Environmental Engineering Reference
In-Depth Information
than additions in northeast Colorado. Bringing more wind on line, regard-
less of the location, decreases the probability of consistent hour-to-hour
operation and increases the probability of extreme ramping events.
CapacityChallenges
Capacity challenges can be thought of as total magnitude events or longer
time scale events. Mitigation of ramp rate challenges through forecasting
and other information-based solutions must be addressed when the capac-
ity of a system changes. One example of a capacity event is a general lack of
wind generation on a hot summer day when loads are at maximum. Another
example of a challenge occurs when the low load hours of spring coincide
with high wind generation and create a need to “dump” energy.
Figure  1.5 depicts the load that Xcel/Public Service must meet based on
data from 2006. The load is sorted on an annual basis ranging from the high-
est hour of generation requirement to the lowest. The highest hour require-
ment is about 8 GW and the lowest is about 3 GW. Three wind generation
scenarios are presented. The top line represents the load that must be met
without regard to wind generation. Current net load indicated by the middle
line indicates the 2006 load curve minus the generation from about 1 GW
of wind distributed around Colorado to model the current wind system.
The line next to the bottom shows the net load 1500 MW wind in north-
east Colorado (current system) with an additional 480 MW of wind genera-
tion added to the Peetz geographic area. The net load 1500 MW in southeast
Colorado (bottom line) represents the current system plus an additional 480
Xcel PSCo Load Duration Curve and Net Load
Duration Curves
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
Xcel Energy PSCo 2006 Load
Duration Curve East and West
Current Net Load 1000 MW
Wind
Net Load 1500 MW wind NE
Colorado Addition
Net Load 1500 MW SE Colorado
Wind Addition
Hours of the Year
FIGURE 1.5
Xcel Energy/Public Service Company of Colorado load duration and net load duration curves
(wind at 1 and 1.5 GW) for 2006.
Search WWH ::




Custom Search