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Demand-Side ManagementInfluence on Reliability
NERC Demand-Side Management Task Force (DSMTF)
Rick Voytas, Chair November 2007
Presented To The U.S. Demand Response Coordinating Committeee
National Town Hall Meeting
Washington, D.C.
June 3, 2008
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DSMTF Initial Charter
Review Current Data Collection methods.
Review Energy Efficiency influence on reliability
Evaluate existing DSM reliability performance metrics.
Discussion and summary of the above tasks integrated into a White Paper for review by the
1. Resource Issues Subcommittee2. Operating & Planning Committee at their December 3-4, 2007
● NOTE: Subsequent NERC task force formed to delve into data collection metrics
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DSM & NERC’s Data Collection
Demand Side Management (DSM)
Demand Response Energy Efficiency
Dispatchable Non-Dispatchable
Controllable Economic
Energy-PriceCapacity AncillaryEnergy-
Voluntary
Direct Load Control
Interruptible Demand
Critical Peak Pricing
w/Control
Load as a Capacity Resource
Spinning Reserves
Non-Spin Reserves
Regulation
EmergencyDemand Bidding & Buyback
Time-Sensitive Pricing
Time-of-Use
Critical Peak Pricing
Real Time Pricing
System Peak Response Transmission Tariff
Phase 1 Areas of InterestPhase 1 Areas of Interest
Phase 2 Areas of InterestPhase 2 Areas of Interest
NE
RC
Cur
rent
ly
Col
lect
s D
ata
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NERC Definition Of Reliability
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Reliability Discussion Continued - Avoided Capacity Concept
Avoided Capacity – measured as the amount of capacity that can be displaced while meeting the systems reliability criterion.
Cost vs Benefit
Avoided Capacity Benefit
ACB = (G + T) x D X CE
G - avoided cost of generation in dollars per kW year (incl. fixed O&M)T – avoided cost of transmission in dollars per kW per yearD – system coincident peak demand reduction associated with the program in kWCE – Capacity Equivalence of the potential program, expressed as kW of capacity value per kW reduced at system coincident peak
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Avoided Capacity
What is Capacity Equivalence (CE)?Capacity Equivalence is the true capacity value of a program (DSM, DR, wind,
hydro, etc)
Bottom line: 1 MW of DSM ≠ 1 MW of Gas ≠ 1 MW of Coal Generation
Why?The calculation of the amount of reserve MW at time of system peak may not provide an indication of the capacity, or load relief, that will be available throughout the entire year to meet customer requirements.
Two important properties: Determined at system level with adjustments for reserve margin and
distribution losses Varies according to the pattern of load relief afforded by the potential program
Capacity Equivalence
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Avoided Capacity
Capacity Equivalence
GenerationMax
CapabilityScenario #1
Summer
Scenario #2
Winter(1)
Scenario #3
Winter(2)
Coal plant #1 200 200 100 200Coal plant #2 300 300 300 0Combustion Turbine 50 50 50 50DR program 50 50 0 0
TOTAL 600 600 450 250
Customer Demand 490 390 390Percent Reserves 18% 13% N/A
(1) plant #1 is sheduled for maintenance
(2) plant #2 has an unforced outage
ACME Utillity Company
short capacity!short capacity!
Example using a DSM program that relies on AC reduction:
short reserves!short reserves!
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Avoided Capacity
History of Reserve Margin Earlier years of utility, “percentage reserve” evolved as the means for
communicating the “reliability” of a utility system
“Percentage reserve” at system peak established an amount of capacity in MW that would be available to the system at peak and throughout the year
Problem: The amount of capacity actually available at any point in time would be reduced due to random forced outages and scheduled maintenance
In 1978, many reliability councils adopt Loss Of Load Probability (LOLP) methodology
Most reliability councils adopted the industry standard of .1 day per year (LOLP = .1) .1 day/year = 1 day in 10 years = one day in 2500 workdays
Using a LOLP =.1, minimum reserve margins can be calculated
Reserve Margin
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NERC Historical On-Going Metrics and Data Requirements