Environmental Engineering Reference
In-Depth Information
TABLE 1.1
Comparison of Pumped Storage Size Sensitivity Cases
WindIntegrationCost($/MWh)
($5/MMBtugas)
CaseName
C0 - No Cabin Creek Units
$10.19
C1 - 1 Cabin Creek Unit
$7.49
C2 - 2 Cabin Creek Units
$5.75
C3 - 3 Cabin Creek Units
$5.34
C4 - 4 Cabin Creek Units
$4.55
C4 - 6 Cabin Creek Units
$2.78
Source:
Zavadil, R. M., (2006). “Wind Integration Study for Public Service Company of
Colorado”. Available online via National Renewable Energy Laboratory, http://www.
nrel.gov/wind/systemsintegration/pdfs/colorado_public_service_windintegstudy.pdf
(December 5, 2008)
Sullivan, Short, and Blair published a complementary document to the U.S.
Department of Energy (DOE) publication titled “Twenty Percent Wind Energy
by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply.”
7
The Sullivan et al. report, “Modeling the Benefits of Storage Technologies
to Wind Power,”
8
states, ”Given an ideally integrated grid, this [energy stor-
age] capacity would not be necessary [for integration] because the pooling
of resources across an electric system eliminates the need to provide costly
back-up capacity for individual resources…. It is the net system load that
needs to be balanced, not an individual load or generation source in isola-
tion. Attempting to balance an individual load or generation source is a sub-
optimal solution to the power system operations problem.”
9
The modeling devised to produce the “Twenty Percent by 2030” report
lacked the capability to model storage as a component of utility develop-
ment. Regardless of the capability of the model, the statement suggests that
storage for any individual resource on a system scale is not needed; but as the
total system variability increases, a resource (storage or other) will be needed
to manage that variability, and that leads to an important question. When
does a system need a storage resource? Sullivan and colleagues addressed
the question and found that at high levels of penetration, storage can lead to
more wind power installations and the ability to store electricity adds value
to a system as a whole and to wind power in particular.
Four general models were constructed and run to generate comparisons of
business-as-usual utility development with and without storage and a 20%
wind energy requirement with and without storage. The results showed that
business-as-usual utility development with and without the capability to
build and use storage allowed an increase in year 2050 wind capacity from
302 GW with no storage to 351 GW with storage. Thus, the additional capac-
ity development of wind without storage is less than the development with
storage. These modeled scenarios show the wind and storage development
replacing capacity and generation from conventional sources.
