exeter a ssociates, i nc. march 29, 2006february 17, 2008 1 new transmission initiatives for...
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EXETERASSOCIATES, INC.
March 29, 2006February 17, 2008
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New Transmission Initiatives for Renewable Energy and Some Thoughts on Wind
Integration
Kevin Porter
NARUC Winter Meetings Staff Electricity Committee
Washington, D.C.
EXETERASSOCIATES, INC.
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Presentation Outline
Transmission Initiatives for Building Transmission in Advance of Generation
Basic thoughts on wind integration Sources of additional information
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Renewable Energy and Transmission
“Chicken and egg” problem can be quite severe with transmission and renewable energy Renewable energy developers do not always have the
financial capability to support large-scale transmission investments
Transmission is not built because it is not evident that renewable energy projects will be developed to use the transmission
Various initiatives underway CA ISO Location Constrained Resource Interconnection Competitive Renewable Energy Zones (Texas, Colorado) Open Season (BPA)
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CA ISO Location Constrained Resource Interconnection
Non-network facilities that would connect at least two eligible and unaffiliated generators in identified energy resource areas
Must go through the CAISO Transmission Planning Process and turned over to the CAISO’s operational control once in operation
Costs are rolled into the CAISO’s transmission access charge until generators come on-line, after which generators pay pro rata share of going forward costs
Demonstrated interest of 60% or more of transmission capacity, of which at least 25% is from interconnection agreements
Limited to 15% of total net high-voltage transmission plant investment of participating transmission owners in CAISO
Approved by FERC in December 2007
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Competitive Renewable Energy Zones
Identifies zones with high clean energy potential and transmission necessary to access it
In Texas and Colorado; description here largely based on Texas
Zones in Texas determined by availability of renewable energy resources, suitability of land and financial commitment of generators to construct renewable capacity. Zones nominated by utilities in Colorado, subject to action by the Colorado PUC.
Recovery of transmission costs Spread across all LSEs in Texas Via rate adjustment clause in Colorado (including planning
and development costs and construction work in progress) In Texas, developers must deposit letter of credit for 10% of
their assigned share of the estimated costs identified in the transmission plan. No such requirement in Colorado
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BPA Open Season
BPA has several proposed projects in interconnection queue BPA has proposed open season to determine zones or clusters
to study for new transmission All requestors of transmission service must participate in open
season or forfeit their position in the BPA interconnection queue
One year’s worth of transmission charges in advance, unless customer pays for transmission upgrade costs in advance
Instead of participant funding, BPA proposes to estimate expected reliability, economic and “future use” benefits of new transmission and recover those in BPA general revenue requirements
Under discussion; may take place later this year
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Basic Issues to Contend With Concerning Wind Grid Integration
Grid operation requires balance between generation and load Wind generation cannot be controlled and scheduled with a high
degree of accuracy Goal is to manage net system variability and net system
uncertainty, not the variability or uncertainty of wind and solar
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Impact of Variable Power Sources
Power system is designed to handle tremendous variability in loads
Wind adds to that variabilitySystem operator must balance
loads=resources and meet reliability standards
It is not necessary or desirable to match wind’s movements on a one-to-one basis
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Wind Myths
For each wind power plant, a conventional generator must be kept standing by in case the wind does not blow
Wind requires storage The wind only generates energy 25-35% of the time (it is really
~80%) These myths have been refuted by
Extensive analysis Operating practice of wind plants around the world
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Factors that Influence Wind Integration
Balancing area size Generation Mix Wind resource geographic diversity Market-based or self-provided ancillary
services Size of interconnected electricity markets
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Lessons Learned So Far The costs for integrating wind is non-zero and increases as the proportion of
wind generation to conventional generating resources or peak load increases. Reserve costs attributed to wind integration are relatively small at wind
penetration levels of less than 20%. These costs generally increase as the level of wind penetration increases.
How the variability and uncertainty of wind generation interacts with variations in load and load forecasting uncertainty has a large impact on the level of wind integration costs.
The level of geographic concentration of wind projects also affects wind integration costs. Greater spatial diversity of wind projects can lessen the fluctuations in wind output and therefore lessen wind integration costs
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Large-Scale Studies in ProcessWestern Wind & Solar Integration Study
30% Wind in footprint, 20% in WECC
Eastern Wind Integration Study
LEGEND
WestConnect LinesCalifornia LinesLADWP LinesDC Lines
Control areas:APSEl PasoNevada PowerPNMSierra PacificSRPTristateTucsonXcelWAPA
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Further Information National Wind Coordinating Collaborative Bi-Monthly
Transmission Update Calls Open to all Next one is March 11th at 1 p.m. Eastern http://www.nationalwind.org/publications/transmission/upd
ates/default.htm
Contact me or Katie Kalinowski at [email protected] Table on RTO market rules and wind power
http://www.uwig.org/windinmarkets.htm Table on New Transmission Proposals
http://www.awea.org/policy/regulatory_policy/transmission_documents/Expansion/Summary_ProactiveTransmissionPolicies_Jan2008.pdf
Wind Integration Studies http://www.uwig.org/opimpactsdocs.html 13
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Further Information (2)
• IEEE Power Engineering Society Magazine, November/December 2005•Updated in 2007• IEEE Wind Power Coordinating Committee Wind Super-Session, Summer 2008• Utility Wind Integration Group (UWIG)
• Spring meetings in Dallas April 16-17
• www.uwig.org
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March 29, 2006
Contact Information
Kevin PorterExeter Associates, Inc.
5565 Sterrett Place Suite 310Columbia, MD 21044
410-992-7500410-992-3445 fax
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Accommodating Higher Levels of Wind and Solar Generation
Flexible, quick response generation with minimum turndown should be emphasized for future resource additions
Note that retirements may accelerate due to variable renewable generation
Market design that encourages and rewards maneuverable generation
Elimination of contractual obligations that thwart maneuverability
Inventory generation capability Consolidate balancing areas, or mimic consolidation
through sharing energy imbalances, area control area, etc.
Price-responsive load and demand response Perhaps plug-in hybrids in the future
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Accommodating Higher Levels of Wind and Solar Generation (2)
New transmission can enhance the grid’s ability to accommodate variable renewable energy generation
Making the most of existing transmission
Explore alternate line/path rating criteria (e.g., wind plants would rarely be at full output simultaneously due to spatial diversity)
Explore new technologies, including:
Real-time line ratings
Controls to manage output from multiple variable renewable resources
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Accommodating Higher Levels of Wind and Solar Generation (3)
Curtailment – reduce or limit output of intermittent generation (wind) during periods of low load and high wind and high hydro
Forecasting – Encourage development and use of improved wind and solar forecasting methods
Day-ahead for unit commitment on grid-wide basis
Hour-ahead for real time operation
Monitoring – Record and archive operational data from existing new intermittent renewable generation (meteorological and MW)
Verify actual operational characteristics versus expectations
Refine operating practices, performance, and flexibility requirements
Data for future studies of grid operation and performance with increased intermittent renewable generation