Common Case Package Discussion
TBD
Tom Miller- MWG Chair
Jamie Austin- DWG Chair
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
2
Discussion Topics
•
•
•
•
•
W
E
Overview Common Case Package
Common Case Standard Sensitivities
Standard Sensitivity Documentation
Common Case Package Attributes
Next Steps
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
3
Common Case Package
Standard Sensitivities
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
4
Common Case Package
Common Case Package
• 10-Year Common Case
• Standard Sensitivities
Process Enhancements
 Communicated in Study
Request Form for Study
Program along with
information for alignment
with 20-year Scenarios
– High and Low Load
– Wet and Dry Hydro
Sensitivities
– High and Low Natural
Gas Price
– Range CO2 Prices
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
 TAS Working Groups and
Task Forces will review
sensitivity assumptions
for each study cycle
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
5
Common Case Package Attributes
 Sensitivities on key variables relevant to Western Interconnect and serve as “robustness” test of Western
Interconnect
 Provides insights into impacts of SINGLE key variable
 Allows increased study case comparisons
 Common case plus sensitivities provide building blocks
for study case aggregations and better alignment with
SPSG Scenarios
 Provides Stakeholders a more comprehensive
common-case data-set (s)
 Use simplified assumptions as trade-off to achieve high
value but reduce staff work load burden
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
6
Common Case Standard Sensitivities
• Insights to resource dispatch, transmission flows,
operating constraints, over-generation
• Tests robustness of the Western Interconnect to
handle impacts of key planning uncertainties
• One variable change of key drivers
• Key Sensitivities (current)
– High and Low Load (+/- 10%)
– Wet and Dry Hydro Sensitivities (2001 and 2011): provides
bookends
– High and Low Natural Gas Price (+50%, -34%): reflects range
of historical price volatility
– High and Low CO2 Price: 0-60/ton status quo to two tiers of
CO-2prices that captures “tipping point” for NG and Coal
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
7
Standard Sensitivities- Documentation
• Summary:- Sensitivities on individual key variable off the 10-year
Common Case on key variables including:
– Load (High/Low)- (e.g. +/- 10%)
– Hydro Conditions (High, Low) e.g. Historical 2011 and 2001
– Natural Gas prices (High, Low)- e.g. +50%/-34%
– CO2 Costs (Range TBD)- e.g. $0-60/ton
• Key Issues :- Impacts of each key variable on system dispatch,
transmission flows and GHG
• Broad Value: Sensitivities will provide more comprehensive insights into
the impacts of key variables off the deterministic 10-year Common Case .
Provides robustness test of WI addressing planning uncertainties
• Expertise:- Yes. Final defining of variables will be managed through the
TAS working groups
• Stakeholders Interest: Majority
• Study Limitations: only captures impacts of single key variable
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
8
Next Step
MWG collaborate with SWG, DWG and WECC-staff to:
o Draft- Common Case Package summary description for TEPPC
Planning Protocol and TAS Charter
o Draft- Appendix for Individual Sensitivity Write-ups similar the
study requests
o Process- Flexibility for TAS to update assumptions each
study cycle
o Draft- Language to inform Study Request Window




W
E
Initial Draft Review by TAS Working Groups & WECC Staff
Update Drafts Based on WG’s Comments
Final-Draft to TAS as approval item
Seek TEPPC Approval
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
9
2024 Common Standard Sensitivities
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
10
Load Sensitivity
Summary:- High and Low load sensitivity studies are designed to study a plausible range of
demand uncertainty over the 10-year planning horizon. Load modifications will be applied using a
simplified weighted scaling off the common case.
High Load (+) 10%
Low Load (-) 10%
Renewable build out will not be adjusted to preserve the load balance uncertainty from the planned
trajectory of the Common Case
Key Issues :• What are utilization/congestion impacts to the transmission system when loads are changed
from what is modeled in the 2024 Common Case?
• What is the impact to the system constraints such as over-generation, energy not served,
min-generation requirements and/or reserve violations?
Broad Value: Sensitivities will provide more comprehensive insights into the impacts of key
variables off the deterministic 10-year Common Case. Robustness test of WI addressing planning
uncertainties
Expertise:- Yes. The range of adjustment will be reviewed and updated through the DWG
Other Stakeholders: Majority
Study Limitations:• Will not capture potential changes in loads shapes or peak vs. energy growth.
• Will not capture impacts to specific load drivers such as economic load growth, energy
efficiency, or electric vehicles.
• Reliability impacts of the high- and low- loads won’t be evaluated in these studies.
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
11
Hydro Sensitivity
Summary:- High and Low Hydro study cases assume Western Interconnection-wide
simultaneous hydro conditions defined using single years for the high-hydro (2011) and lowhydro (2001) conditions, respectively.
Key Issues :-
•
How does production cost, generation dispatch, transmission congestion, and
transmission utilization change under a range of Western Interconnection-wide hydro
conditions?
Broad Value: Sensitivities provide comprehensive insights into the impacts of key variables off
the deterministic 10-year Common Case . Robustness test of WI addressing planning
uncertainties
Expertise:- Yes. Reference years to be reviewed by the Hydro Modeling Task Force
Other Stakeholders: Majority
Study Limitations:-
•
The high-/low-hydro conditions of historical years 2001 and 2011 together represent
overall system high-/low-hydro conditions, the sensitivities will not address impacts of
high/low hydro conditions in individual water basins.
The reliability impacts of the high- and low- hydro conditions won’t be evaluated in
these studies.
•
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
12
NG Price Sensitivity
Summary:- Natural Gas (NG) High and Low Price sensitivity studies are designed to study natural
gas price conditions within the bounds of historical volatility and potential of market conditions.
Changes will be applied proportional/directly to all TEPPC NG fuel areas, as in the common case.
High Gas Price – NG prices increased by 50%
Low Gas Price – NG prices decreased by 36%
(Optional) Very High Gas Price – NG prices increased by 100%
(Optional)– Very Low Gas Price – NG prices decreased by 50%
Key Issues :• What are utilization/congestion impacts to the transmission system when natural gas prices
are changed from what is modeled in the 2024 Common Case?
• What is the impact to the variable production cost?
Broad Value: Sensitivities will provide more comprehensive insights into the impacts of key
variables off the deterministic 10-year Common Case . Robustness test of WI addressing planning
uncertainties
Expertise:- Yes. The reference years are based on the review and recommendations by the DWG
Other Stakeholders: Majority
Study Limitations:• Will not capture regional variations in NG Prices or changes in NG “basis” differential
• The reliability impacts of the high- and low- NG Prices won’t be evaluated in these studies.
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
13
CO2 Price Sensitivity
Summary:- The CO2 Price sensitivity designed to study the impact of a range of “carbon” price on the
commitment and dispatch of thermal generation in the common case
Carbon Tax ($/metric ton)
Case
Description
WECC (nonCalifornia
California
PC1
27.51
0.00
Common case for reference
PC10-15
27.51
15.00
Assume that California would not lower their tax
PC10-27
27.51
27.51
Apply AB32 tax WECC-wide
PC10-40
40.00
40.00
WECC-wide $40 tax
PC10-50
50.00
50.00
WECC-wide $50 tax
PC10-60
60.00
60.00
WECC-wide $60 tax
PC10-0
00.00
0.00
Optional case that removes AB32 from PC1
Key Issues :• Interaction of the coal fired resources in relation to gas fired resources.
• How might production cost, generation dispatch, transmission congestion/utilization change
Value: gain insight into the impacts of CA Global Warming Initiative (AB32) policy vs. an expanded CO2
price policy
Expertise:- Yes. Modeling of CO-2 prices developed/updated through MWG /DWG
Study Limitations: initially will not address uncertainties EPA 111d on a state by state basis
W
E
S
T
E
R
N
E
L
E
C
T
R
I
C
I
T
Y
C
O
O
R
D
I
N
A
T
I
N
G
C
O
U
N
C
I
L
Questions and Comments?
Contact Information:
Tom Miller
Pacific Gas and Electric Company
Energy Procurement- Integrated Resource
Planning Group
[email protected]
(415) 973-2070