Transcript Document

Demand-Side Management
Influence 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
1
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.
2.
●
Resource Issues Subcommittee
Operating & Planning Committee at their December 3-4, 2007
NOTE:
Subsequent NERC task force formed to delve into data
collection metrics
2
DSM & NERC’s Data Collection
Demand Side Management (DSM)
Demand Response
Dispatchable
Controllable
Capacity
Ancillary
EnergyVoluntary
Energy Efficiency
Non-Dispatchable
Economic
Time-Sensitive Pricing
Time-of-Use
Energy-Price
NERC Currently
Collects Data
Critical Peak Pricing
Direct Load
Control
Spinning
Reserves
Interruptible
Demand
Non-Spin
Reserves
Critical Peak
Pricing
w/Control
Emergency
Regulation
Demand
Bidding &
Buyback
Real Time Pricing
System Peak Response
Transmission Tariff
Phase 2 Areas of Interest
Load as a
Capacity
Resource
Phase 1 Areas of Interest
3
NERC Definition Of Reliability
4
Reliability Discussion Continued - Avoided Capacity Concept
– measured as the amount of capacity that can be
displaced while meeting the systems reliability criterion.

Avoided Capacity

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 year
D – system coincident peak demand reduction associated with the program in kW
CE – Capacity Equivalence of the potential program, expressed as kW of capacity
value per kW reduced at system coincident peak
5
Avoided Capacity
Capacity Equivalence
 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
6
Avoided Capacity
Capacity Equivalence
Example using a DSM program that relies on AC reduction:
ACME Utillity Company
Max
Capability
Generation
Coal plant #1
200
Coal plant #2
300
Combustion Turbine
50
DR program
50
600
TOTAL
Customer Demand
Percent Reserves
Scenario #1
Summer
200
300
50
50
600
Scenario #2
Scenario #3
(1)
(2)
Winter
490
18%
Winter
100
300
50
0
450
200
0
50
0
250
390
13%
390
N/A
(1) plant #1 is sheduled for maintenance
(2) plant #2 has an unforced outage
short reserves!
short capacity!
7
Avoided Capacity
Reserve Margin
 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
8
NERC Historical On-Going Metrics and Data Requirements
9