Title: Regional Transmission Adequacy Guidelines Technical Workshop
1Regional Transmission Adequacy Guidelines(Technic
al Workshop)
- PDX Conference Center
- June 3, 2005
- Ravi K. Aggarwal
2Action Items (Apr. 27)
- Process Clarification
- Transfer Vs Load Service Issues
- Reasons for limitations on COI/PDCI and NI
- Other ongoing efforts for developing Transmission
Adequacy Guidelines - Revised studies for N-2 and N-1-1
- Benefit/Cost Tools and Other Tools to measure
system performance and identify system
requirements
3Process Objective
- How does the region address transmission adequacy
challenges that current reliability criteria
dont address? - How do the existing NERC/WECC standards for the
bulk system apply to local load areas - What guidelines are needed to address challenges
that we have planning economic upgrades? - Current NERC/WECC address physical adequacy and
not economic adequacy
4Value Proposition
- Better informed investments Addressing Physical
and Economical aspect of transmission system - Controlled costs
- Application of appropriate risk
5Risk Assessment
- Establish Context Transmission Planning
- Identify Risk factors ? Serves as a checklist
- Analyze (Quantifiable) Provide importance of
risk (rank) and Consequences - Evaluate Summarize risks in terms of decision
(alternate, timing, etc) - Treat Define Actions to mitigate or reduce
(manage) risk
6Risk Assessment(Redefine Thresholds)
Make Better Informed Decision (Systematic,
Controllable, Measurable, Repeatable)
Identify level where we do not take risk
Redefining Thresholds (Suggestive) MW Loss
(Magnitude) Duration Exposure Time and
Condition Outage history Probability of outage
Ref. BPA Risk Assessment Tool
7Issues
- Load service issue (e.g., Olympic Peninsula
Energy Efficiency/DSM) - N-2 requirements (should it be based on MW or
geographic scope) - Robustness of the system N-1-1?
- Metrics to measure performance
- Minimum guidelines need to focus on customer
requirements - Native load Vs. firm transmission customers (PTP)
? Eventually tie to transfers
8Firm Transfers Vs Load Service
- Economic Decision
- FERC Treat firm transfers and load as same
- Routine Cut transfers to avoid load shedding
- Build Transmission?
- Consequences
- Build for low probability event
- Upward pressure on rates
9N-2
- Local Area Network
- Loads and Transfers
- N-2 benchmarking discussed for following areas
- BPA Load areas (Olympic Peninsula, and So.
Oregon Coast) - PAC So. Oregon
- Snohomish System
10Olympic Peninsula
11Southwest Oregon Coast
12(No Transcript)
13N-1-1
- One element is out of service and a unplanned
contingency trips another element - Power system generally not planned to operate for
all N-1-1 conditions (Number of combinations are
tool large to plan and cost of the infrastructure
needed will be too high) - Operations cannot mitigate all N-1-1 conditions
with the available tool box (Safety Net?)
14Examples
- Puget Sound - PSANI
- Eugene Area
- Redmond Area
- Suggested Solutions
- Under-voltage load shedding
- Coordinated Planned Outages (timeframe)
- Does not cover for unplanned outages
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16Example N-1-1(Eugene Area)
- Outage of one of the 500/230 kV transformer banks
at Santiam, Lane, or Alvey - Next outage of any of the other remaining bank in
the area results in extremely low voltages ?
Potential Voltage Collapse - This problem does not appear to be confined to
winter operations.
17Possible Solutions (Eugene Area)
- Ensure sufficient under-voltage load shedding is
available in the immediate area, and that its
settings will allow it to operate in time to
prevent large-scale problems. - Concern
- Under voltage load shedding available between
Nov. 15-Apr. 15 (WILSWA) - Under voltage load shedding designed for winter
season (voltage sensitive load). Does this cover
for summer load conditions? - Other than winter Reactive capability available
but not on Coordination for faster reactive
insertion scheme - Outages taken outside this timeframe
18Example N-1-1(Redmond Area)
- Outage of the Ponderosa 500/230 bank, or the
Round Butte 500/230 bank - When an outage is taken that affects service from
one of these transformer banks (e.g.
Grizzly-Summer Lake 500 kV line), a contingency
that affects service from the other 500/230 bank
can cause the voltages in the Redmond area to
collapse. - Approximately 90 of the Redmond area load is
served by these two transformer banks
19Possible Solutions (Redmond Area)
- Under-voltage load shedding Possible addition in
the Redmond area provides safety net - Transmission Build Expensive alternative
- RAS Controller Expensive alternative
- Note Same flexibility may not be available for
other areas. Cutting transfers are not always the
solution. The problem is a embedded local
problems.
20Alberta Transmission Development Study
- Develop LT Planning framework for AIES
- Need Accommodate variety of alternate generation
expansion scenarios - Assessment of overall delivered energy cost
(generation plus transmission) under various
transmission and generation development scenarios - Strategic Decision Process Use of scenario
planning to identify combinations of possible
future events - Alberta Interconnect Electric System
Ref. Navigant Consulting AESO (Jan. 2004)
Alberta Transmission Development (A Scenario
Approach) Summary Report
21Methodology
- Use of scenario analysis
- Range of potential transmission, generation, load
forecasts, and export scenarios - Identify and determine transmission cost
- Determine energy cost
- PV of overall delivered energy costs
Ref. Navigant Consulting AESO (Jan. 2004)
Alberta Transmission Development (A Scenario
Approach) Summary Report
22Report Analysis
- Optimization of transmission development
requires maintaining flexibility to better manage
uncertainties associated with generation
Competitive market for electricity
Ref. Navigant Consulting AESO (Jan. 2004)
Alberta Transmission Development (A Scenario
Approach) Summary Report
23Linkage of Resource and Transmission Adequacy
Adequacy Physical (lights stay on) and
Economic (acceptable risk that prices reasonable
not volatile) or just Physical?
2 10 Years out
Resource Adequacy
Transmission Adequacy
Timeframe
Power System Adequacy
Power System Reliability Operational Adequacy
Well-Functioning Electricity Markets
Within Year
Source NW Resource Adequacy Metrics Standards.
TAS meeting, Jan. 10, 05, PDX.
24Proposed Methodology
- Consequence
- Peak load
- Fraction of load that can be served under N-2
- Exposure
- Likelihood of outage(s)
- Load-duration curve
- Benefit/Cost analysis
- Cost to fix
- Societal cost of outages
25Contact Information
- Ravi K. Aggarwal Chair
- Bonneville Power Administration
- Phone (360) 619-6681
- Fax (360) 619-6945
- Email rkaggarwal_at_bpa.gov
- OR
- Dana Reedy - Facilitator
- Northwest Power Pool
- Phone (503) 464-2806
- Email dana.reedy_at_nwpp.org
26Backup Slides
27Potential Elements of a Transmission Adequacy
Guidelines
- Reliability Standards
- NERC, WECC and Utilitiy standards
- Explicit performance criteria such as LOLP
- Probabilistic criteria
- Robustness tests
- Extreme event tests
- WECC standards are more restrictive than NERC
and utility standards
- Economic Indicators
- Societal benefit/cost analysis of reliability
Value of load loss - Acceptable levels of congestion
- Definition of least cost solutions
- Price volatility and tolerance
- Assurance level for maintaining ATC across
flowgates
28Potential Elements of a Transmission Adequacy
Guidelines
- Other Objectives
- Development of renewable
- Resource diversity
- Economic development
- Seasonal products
- Expansion Pricing Policy
- Drivers
- Generation
- Load
- Transfers into, out of and through the region
- Flexibility
- Financial
- pricing expansion
- Advance financing requirements or other risk
management tools
29Possible Solutions
- Amounts and obligations for RAS (or special
protection scheme) - Re-dispatch (mechanisms)
- Curtailment strategies
- Non-Wires Solutions
- Changes to maintenance practices to provide for
more flexibility - Better load forecast mechanisms
- Investigate and incorporate new technologies
- Locational Marginal Pricing (LMP) Requires
formation of an Independent Transmission Operator - Computer tools to assess state of the
transmission system in real-time
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31Olympia-Shelton and Shelton Transformer
Fairmount
W
69kv
W
Port Angeles
South Bremerton
W
W
115kV
W
Kitsap
Shelton
230kV
S. Shelton
W
230kV
W
X
15 mi
Satsop
.
X
White Rv
230kV
Olympia
W
W
Coulee
Paul
500kV
6 mi
Source Mark Bond BPA (Transmission)
32Olympic Peninsula Support (Three Primary
Problems)
- Voltage Stability Problem - for an outage of the
Olympia 500/230-kV transformer or line - Voltage Collapse Problem - for an outage of both
Olympia-Shelton 230-kV lines - Voltage Collapse Problem - for an Outage of the
Olympia 230-kV East Bus Section
Source Mark Bond BPA (Transmission)