The History of Load
Participation in ERCOT
DOE Workshop—Washington, DC
Mark Patterson
ERCOT Manager of Demand Integration
October 25, 2011
In the Beginning….
2002
– Texas Energy Markets are opened to competition
– Legacy interruptible programs are eliminated
– Large Industrial customers want to participate in Ancillary Service
Markets
– Market Rules (Protocols) changed to add new type of resource called
Loads acting as a Resource (LaaR)
– Instantaneous Interruptible customers transition to Responsive Reserve
Service (RRS)
– 10 minute and 30 minute customers initially consider providing Non-
Spinning Reserve Service but quickly transition to RRS
– Limits placed on maximum participation (25% of RRS capacity)
– Loads must meet similar requirements as generators
• Real Time Telemetry
• Dispatchable via a verbal dispatch instruction
• UFR for Frequency Response
2
10/25/2011
2002 to 2004
• Deployments are done for System Capacity Insufficiency and
Management of Zonal and Local Congestion
• Loads must have a relatively flat load profile in order to provide RRS
(batch process loads are not allowed to provide service)
• Loads must pass a qualification test to provide service
• 25% limit is raised to 33%
• Protocols are changed to create a new type of Resource called a
CLR but system changes are extensive and not implemented
• Numerous deployments for Zonal and Local Congestion
3 10/25/2011
2005 – 2006
• Protocols are changed to remove zonal deployments
• 33% limit is changed to 50%
• Firm Load Shed in April 2006 and first system wide deployment of
LaaRs
• Some Performance Issues Identified
– 20 minute initial response times
– Real time telemetry issues
– Qualification tests allow simulated testing
4 10/25/2011
• Protocol changes implemented to correct issues
– Simulated testing no longer acceptable – qualification tests
must include an actual deployment
– Tightened telemetry standards
– Provisions added to suspend LaaRs that fail to perform
• Response times go from 20 minute timeframe to 7-8 minutes
• Tests run to demonstrate viability of CLR
• Zonal market ends in December 2010
2007 – 2010
10/25/2011
5
2011
• Nodal Market Implementation
– Deployments now include XML message prior to the verbal
dispatch instruction
– Split deployment stack created
– Full implementation of CLR
6 10/25/2011
7 10/25/2011
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
Apr-02 Apr-03 Mar-04 Mar-05 Mar-06 Mar-07 Mar-08 Mar-09 Mar-10 Mar-11
MW
sLoad Resources Registered and Qualified for
ERCOT AS Market
Impact of Load Resources on AS Markets
10/25/2011
8
ERCOT Load Resources Participating in Responsive Reserve Market
Summary
2006 2007 2008 2009 2010 2011***
Number of Participants 130 130 143 160 181 189
Registered Load (MW) 1966 2069 2153 2063 2382 2391
Load Resource RRS Awards ($ millions) * 48.4 53.2 115.8 41.6 54.1 108.3
Estimate for Total Load Resource Contribution
($ millions) ** 130.0 125.7 267.9 95.5 89.5 182.9
Weighted Average Price for RRS ($) 12.93 12.61 28.68 10.17 9.03 25.27
* Represents only portion that was awarded through ERCOT AS Market Auction
** Estimate for Total Load Resource Contribution uses the weighted average price for RRS as a proxy price for self provided Load Resources
*** Results thru 9/30/2011
Load Resource Response on 2/2/2011
10/25/2011
59.5
59.6
59.7
59.8
59.9
60
60.1
60.2
0.00
200.00
400.00
600.00
800.00
1000.00
1200.00
1400.00
5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00
Load
Res
ou
rces
Dep
loye
d (M
W)
Time (hr:mm)
ERCOT Load Resource RRS Deployment 2/2/2011
Load Resources Deployed (MW) Frequency
9
Load Resource Response on 8/4/2011
10/25/2011
10
59.8
59.9
60
60.1
60.2
0.00
200.00
400.00
600.00
800.00
1000.00
1200.00
14:00 14:15 14:30 14:45 15:00 15:15 15:30 15:45 16:00 16:15 16:30 16:45 17:00 17:15 17:30 17:45 18:00 18:15 18:30 18:45
Load
Res
ou
rces
Dep
loye
d (M
W)
Time (hr:mm)
ERCOT Load Resource RRS Deployment 8/4/2011
Load Resources Deployed (MW) Frequency
Emergency Interruptible Load Service (EILS)
11 10/25/2011
• Service provided by end use customers willing to interrupt during an
electric grid emergency
• An additional tool for ERCOT Operations, deployed ONLY in the late
stages of a grid emergency
• Requirements:
– Can be individual loads or aggregations
– 15-minute interval metering or statistically valid sample approved by
ERCOT
– Capability of interrupting at least 1 MW of load on 10 minutes notice at
any time during the committed hours
– No telemetry required, and not modeled in the Network Operations
Model
– 3 Contract Periods per year, each has 4 time periods
– Performance based on both availability and deployment metrics
– Dispatching and financial performance is between ERCOT and a QSE
12 10/25/2011
0
100
200
300
400
500
600
FebMay08 Oct08Jan09 JunSept09 FebMay10 Oct10Jan11 AprMay11 Oct11Jan12
BH1 BH2 BH3 NBH
Nu
mb
er
of
MW
Pro
cu
red
0
200
400
600
800
1000
1200
14000:
15
0:45
1:15
1:45
2:15
2:45
3:15
3:45
4:15
4:45
5:15
5:45
6:15
6:45
7:15
7:45
8:15
8:45
9:15
9:45
10:1
5
10:4
5
11:1
5
11:4
5
12:1
5
12:4
5
13:1
5
13:4
5
14:1
5
14:4
5
15:1
5
15:4
5
16:1
5
16:4
5
17:1
5
17:4
5
18:1
5
18:4
5
19:1
5
19:4
5
20:1
5
20:4
5
21:1
5
21:4
5
22:1
5
22:4
5
23:1
5
23:4
5
MW
EILS Load Reduction 08/04/2011
Actual MW Baseline MW Obligation Load Reduction
Questions?
ON
OFF
10/25/2011
14
Top Related