Transcript CPUC Briefing on Renewables for RA workshop

Integration of Wind Resources in
CAISO Markets and Grid Operation
APEx 2007 Program
October 15-16, 2007
Anjali Sheffrin, Ph.D.
Chief Economist & Director, Market Design &
Product Development
Individual States take lead in fight against global
warming
“Today California will be a leader in the fight against global
warming,” said Governor Schwarzenegger. (United Nations'
World Environment Day conference in San Francisco, June 1, 2007)
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Anjali Sheffrin
Renewable Portfolio Standards
CAISO Renewables Integration Program
ISO Corporate Goal: Support the integration of renewable
resources on the California power grid in support of the
State of California’s policy regarding renewables.
Project encompasses the integration of renewable
resources into CAISO’s
 Transmission planning
 Markets, and
 Grid Operations
Objective is to support the State’s goal of 20% of customer
load being served by renewable resources by the end of
2010 and 33% by 2020.
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Anjali Sheffrin
Current Level of Renewable Generation in California
Summer 2006
BioMass 1.5%
Solar 0.4%
Wind 2.4%
Geothermal 3.3%
Small Hydro 1.4%
Other Generation
Resources
91.0%
Renewables Provided 9% of the Energy to Serve Customer Load
for the period May through September
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20% Renewables
Existing California Renewable Generation
and Possible Additions to meet the 20% RPS Goal by 2010*
8,000
7,000
13,296 MW Total Renewables
7,319 MW Additonal
5,977 MW Existing
7,267 MW
6,000
MW
5,000
4,577
4,000
Additional
3,191 MW
Existing
3,000
1,214
1,765 MW
2,000
1,073 MW
1,000
1,977
2690
228
845
465
-
Geothermal
Biomass
Wind
* Data on additional renewable resource is based on a current CEC studies on renewables.
Potential retirements of existing resources and repowering projects are not included.
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1,300
Solar
Large amounts of renewable generation are needed to
meet state requirements.
25000
Wind
Geothermal
Biomass
Solar
33%
20000
Megawatts
15000
20%
10000
Current
5000
0
2007
2010
Year
7
2020
California’s abundant wind resources have a key role to
play.
Shasta
Lassen
Solano
County
Altamont
Pass
Tehachapi/
Mojave Desert
Pacheco
Pass
San Gorgonio
Pass
Salton Sea
Imperial Valley
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What are the Major Challenges of Integrating Intermittent
Resources ?
Barriers to Efficient Interconnection and Transmission
Planning
 Funding challenges for transmission to remote locations and
existing transmission policies distinguishing reliability and
economic upgrades
Operating Issues
 Frequency regulation, load following, and operating reserves;
 Ramping problems; over generation control
 Importance of forecasting of renewable energy;
Application of WECC standards for wind generators
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Removing Barriers
to Efficient Interconnection Policies
Problem: Current Interconnection Policies Creating a Barrier
 Long standing FERC policy offers two approaches for financing transmission upgrades:
• Network transmission facilities rolled into Transmission Access Charge
• “Tie-line” facilities paid for by power plant owners
CAISO proposed solution: Distinct new category of transmission serving
multiple power plants in areas where the energy sources cannot be
transported
 Facilitate capturing economies of scale associated with renewable energy development
 Promote overall development of diverse renewable resource opportunities
Key elements of new interconnection policy for locationally constrained
resource areas
 Financing Mechanism Allows Appropriate Sizing
• Lines paid for by transmission owners
 Risk of Stranded Costs Systematically Mitigated
• California Energy Commission designation as a significant resource area
• Multiple projects in the area
• CAISO must find the project to be cost-effective
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Eligibility Criteria for Transmission to Locationally
Constrained Resource Areas
Must be non-network
Must provide access to an area with significant potential for
development of locationally constrained resources (i.e.,
renewables) as designated by the CEC
Must be turned over to ISO control
Transmission to serve multiple facilities
Cannot exceed 15% of the sum total of the high-voltage
network plant included in the Transmission Access Charge
Must meet a commercial interest test - i.e. sufficient
generator interest through Large Generator
Interconnection Process
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Removing Barriers to Effective Transmission Planning
Problem: Planning for reliability upgrades only and economic
upgrades to be market driven
ISO proposed solution:
 New transmission planning process for reliability and economic
projects
• Regional planning with all transmission providers in California
• Established Transmission Economic Assessment Methodology (TEAM) as standard
measure for establishing economic need for major transmission projects
 Proactive transmission planning for future clusters of renewable
generation
• Tehachapi Transmission Plan
» Approved on January 24, 2007
» First use of clustering approach
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Transmission Study Results
The Tehachapi Transmission Plan is sound and there are no
serious transient stability or voltage control problems
Key conclusions
 Power factor control is critical - New wind generators must meet
WECC criteria for ±0.95 power factor control
 Low Voltage Ride Through Standard – all new units must meet
WECC LVRT Standard.
 New wind generators should be Type 3 or Type 4 units
 Existing Type 1 Wind Generators in Tehachapi area do not meet
LVRT standards and will probably be lost in event of voltage
collapse
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Ramping issues
• In California, the wind generation energy production tends to be
inversely correlated with the daily load curve. The wind energy
production peaks during the night and falls off during the morning load
pick up. The net result will be morning ramps of 2000 to 4000 MW
per hour for 3 hours – a total of 6000 to 12,000 MW over 3 hours.
Forecasted Hourly Ramps due to Additional Wind Generation
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Wind Generation Output may Change Quickly
Total California Generation
1200
Will Affect Ramp Rates,
Regulation Requirements,
Load Following, Etc.
1000
TOTAL
Pacheco
Solano
Tehachapi
Altamont
San Gorgonio
600
400
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23:01
22:01
21:01
20:01
19:01
18:01
17:01
16:01
15:01
14:01
13:01
12:01
11:01
10:01
9:01
8:01
7:01
6:01
5:01
4:01
3:01
2:01
0
1:01
200
0:01
MW
800
Wind Generation Output may Peak During Off-peak Periods
January 6, 2005 California Wind Generation
TOTAL
Load, MW
400
34000
350
32000
300
30000
250
200
May Lead to Cycling of
Base Load Generation
150
100
26000
24000
22000
50
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23:00:00
22:00:00
21:00:00
20:00:00
19:00:00
18:00:00
17:00:00
16:00:00
15:00:00
14:00:00
13:00:00
12:00:00
11:00:00
10:00:00
9:00:00
8:00:00
7:00:00
6:00:00
5:00:00
4:00:00
3:00:00
2:00:00
20000
1:00:00
0
0:00:00
MW
28000
Operational challenges to incorporating the 20% RPS Target
Increases the amount of regulation resources

Add 170 MW to 500 MW of regulation resources to accommodate rapid changes in wind
and other variables.
• Amount required varies with the season (winter, spring, summer, fall)
• Estimated cost of additional regulation is $30 million annually
Ramping requirement increases

Fast ramping increases by ±15 MW/min to ±25MW/min

Regulation by hydro units will be most important
Supplemental energy dispatches will increase

Morning ramp up will increase by 1000 to 2000 MW per hour

Evening ramp down will increase by 1000 to 1800 MW per hour
Potential Over Generation problems will increase for light load
periods
 Pro rata cuts of up to 800 MW of wind generation production may be
required for an estimated 100 hours per year
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Enhanced Resource Adequacy requirements and
market prices will drive integration of renewables
Resources Required for
Renewables Integration
Generation
Portfolio
Quick Start Units
Fast Ramping
Wider Operating
Range
Regulation capability
Storage
Shift Energy from
off-peak to on-peak
Mitigate Over
Generation
Voltage
Support
Regulation capability
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Demand
Response
Price sensitive load
Responsive to ISO
dispatches
Frequency Responsive
Responsive to Wind
Generation Production
How to make the 20% RPS Target work
Build the planned transmission facilities for
 Tehachapi
 Sunrise Power Link
Require all new wind generators to be Type 3 or Type 4 that meet
Low Voltage Ride Through (LVRT) Standards
Add SVC’s for dynamic VAR regulation
Change Resource Adequacy requirements for generation facilities for
more fast start units, increased ramping, and larger operating ranges.
Integrate wind energy production with changes in hydro dispatch for
meet the need for rapid energy ramps
Increase storage options – 3rd pump operation at Helms, Leaps,
Compressed Air Storage, H.S. Flywheels for regulation and Hydrogen
Storage.
Increase Demand Response options
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Conclusions
The increasing cost of natural gas for fossil
fired plants and declining cost of wind
generation makes wind generation an
attractive source of energy.
We need new methods to control the wind
generation ramps if we are going to
accommodate 6000 to 8000 MWs of wind
generation.
New technology at the turbines site can
provide for response for frequency control.
The regulation and load following burden to
accommodate wind generation is not trivial but
can be managed with good forecasting
techniques and mix of fast ramping
generation resources .
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