Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to...
Transcript of Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to...
![Page 1: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/1.jpg)
1
Grid Limitations
Presentation to the President’s Council of Advisors
for Science and TechnologyAugust 15, 2002 (Revised 8/20/2002)
Ross BaldickDepartment of Electrical and
Computer EngineeringThe University of Texas at Austin
![Page 2: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/2.jpg)
2
Outline
• Overview of the generation, transmission, and distribution system,
• Evolving roles of electric transmission,• Planning of the electricity system,• Merchant generation,• Grid limitations,• Increasing capacity of transmission,• Implications for distributed generation:
– Concentrate on “on-grid” applications,• National energy policy.
![Page 3: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/3.jpg)
3
Overview of Generation, Transmission, and Distribution.
“Central” Power stations
Distributionsubstations
Load LoadLoad
Transmissionsystem
Distributionsystem
Distributed Generation (DG)
LoadLoad
DistributionSystem DG
Load
![Page 4: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/4.jpg)
4
Transmission.
• Provides for “long-distance,” “bulk” transport of energy,
• Accounts for about 10% to 20% of total cost of electric power system,
• Inter-connects almost all electric generation and demand in North American into four huge systems:– potential for trade over large geographical area.
![Page 5: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/5.jpg)
5
Inter-connections in North America
WECC
ERCOT
Quebec
EasternInter-
connection
![Page 6: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/6.jpg)
6
Evolving roles of transmission.
• Bringing power from remote generators:– Historical trend to ever larger generators,
• Inter-connecting utilities to allow sharing of generation “reserves:”– Provide reliability more cheaply,
• Enabling trade:– Opportunities to buy and sell,
• Mitigating market power:– In restructured electricity markets.
![Page 7: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/7.jpg)
7
Planning of the electricity system.
• Historically, utilities planned generation and transmission jointly to meet growing demand:– large central generation projects had long lead
times allowing for transmission to be built,• Restructured electricity markets leave
generation planning (mostly) to the market:– “merchant generation” building smaller
generation projects with shorter lead times.
![Page 8: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/8.jpg)
8
Merchant generation.
• Largely unregulated (economically) owners of generation capacity:– still face environmental regulations,
• Sell energy at market rates,• Assume (most) risk of business decisions,• Harness competition to drive costs down and
develop technology,• Considerable merchant development in Texas,• Can be central or distributed generation or even
“dispersed” resources such as wind power.
![Page 9: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/9.jpg)
9
Transmission.
• Transmission mostly remains regulated:– “rate of return” paid on investments,– incentives for developing technology and
upgrading capacity tend to be weak,• Difficult to plan and build new
transmission,• Limitations on moving electric power are
prevalent in North America, particularly into urban areas.
![Page 10: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/10.jpg)
10
Grid limitations.
• Limit trade opportunities,• Limit opportunities for development of
merchant generation,• Create local market power:
– particularly in “import limited” areas,• Cost of grid limitations on trade and market
power may be large compared to the construction cost of transmission.
![Page 11: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/11.jpg)
11
Grid limitations and new merchant generation.
Existing central generation
Existing demand
Existingdemand Unanticipated
transmissionneeds
New generation
Growing demand
• Existing system. • New generation planned by merchant.
![Page 12: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/12.jpg)
12
Technology to increase capacity of existing transmission system.
• Existing technologies with potential for further development and deployment:– “Reactive compensation,” “phase angle regulators,”
“Flexible AC transmission,” (FACTS), “high-voltage DC light” (HVDC light),
– Range of costs and characteristics,– Several of these are already heavily deployed.
• Rebuilding lines to increase capacity:– “Re-conductor” lines,– Continuing improvements in metallurgy are providing
better conductors.
![Page 13: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/13.jpg)
13
Technology to increase capacity of existing transmission system.
• Development of technology to allow temporary upgrades and re-locatable equipment:– Fast response to announced need,– Re-locatable resources reduce risks of “build it but they
do not come,”– Used extensively in United Kingdom, similar proposals
by affiliated company in United States,• New technologies:
– Super-conducting cables, – Super-conducting magnetic energy storage (SMES), a
distributed energy resource,– Test applications, potential for large improvements.
![Page 14: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/14.jpg)
14
Alternatives to increasing transmission capacity.
• Given a growing demand:– build new transmission (or increase capacity of
existing transmission) and build new (or access existing) central generation, or
– build new distributed generation near demand center (and avoid need for transmission).
![Page 15: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/15.jpg)
15
Distributed generation resources.
• Distributed generation reduces needs for imports and reduces “transmission losses,”
• Helps to mitigate market power in import limited areas,
• Geographically well-positioned generation can provide “voltage support” that enhances the capability of the transmission system:– conversely, “dispersed” DG such as wind power
typically requires additional transmission.
![Page 16: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/16.jpg)
16
Distributed generation resources.Central power station
100 MW capacity100 MW demandTransmission system
105 MW capacity
20 MWdistributedgeneration
125 MWdemand
![Page 17: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/17.jpg)
17
Distributed generation resources,continued.
• May not be economically viable on basis of selling “base-load” energy alone:– Energy conversion efficiency may not be as
high as that of a large, central power station,– “Peaking” opportunities viable if there is an
energy market that differentiates prices over time:
• “Time of use” meters to reflect variation in prices, – How to set up transmission prices that “credit”
these resources for the enhancement to transmission that they provide?
![Page 18: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/18.jpg)
18
Distributed generation resources,continued.
• Transmission expansion, pricing, and interconnection policy have significant effects on distributed energy,
• Generation and transmission are partial substitutes for supplying electricity:– difficult to have effective competition in one
sector while the other is regulated.
![Page 19: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/19.jpg)
19
Demand center versus Distribution system DG.
• Locating close to demand center potentially avoids need for new transmission and can even enhance transmission capability and reliability,
• However, distribution system DG may not provide these benefits without additional distribution system infrastructure:– Integration of distribution system DG requires new or
modified distribution system infrastructure in addition to time-of-use meters,
– Increasing the reliability of end-use customers typically also requires “ride-through” capability using uninterruptible power supply with energy storage.
![Page 20: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/20.jpg)
20
National energy policy considerations.
• Difficult to appropriately regulate transmission because of its partial substitutability with generation:– competition (merchant generation) versus– regulation of transmission,
• How to price scarce transmission capability and “credit” distributed resources?– much of United States still uses property rights
for transmission that explicitly violate physics,– recent FERC decision will change this.
![Page 21: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/21.jpg)
21
National energy policy considerations, continued.
• How to plan expansion of the transmission system?– want incentives that encourage development of
the “right” portfolio of new generation resources,
– encourage entrepreneurial activity and technological development in generation and transmission,
– accommodate growing demand.
![Page 22: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/22.jpg)
22
National energy policy considerations, continued.
• Should “merchant transmission” be encouraged, or the regulated status quo maintained, or alternative regulatory approaches taken?– Who will be motivated to invest in technologies such as
re-locatable equipment and motivated to develop new technology,
• Should distribution system infrastructure be upgraded to accommodate distribution system DG?– Including integration of information technology into
distribution system to enable control and monitoring.
![Page 23: Grid Limitations - users.ece.utexas.eduusers.ece.utexas.edu/~baldick/papers/PCAST.pdfPresentation to the President’s Council of Advisors for Science and Technology August 15, 2002](https://reader033.fdocuments.net/reader033/viewer/2022053020/5f819d6f09e261692a611497/html5/thumbnails/23.jpg)
23
Conclusion.
• Transmission expansion is limited in most urban areas in the US,
• Demand center located generation offers (competing) alternative for meeting demand,
• Policy considerations on regulation of transmission, pricing of transmission capacity, planning and construction of new transmission capacity, implications for distributed generation.