Holistic Power Supply and Delivery Chain – Foundations for a Smart Grid

Stephen Lee

Senior Technical Executive Power Delivery & Utilization

April 29, 2009

US-China Green Energy Council (UCGEC)Smart Grid SeminarPalo Alto, California

2

Outline Of Presentation

• Key Messages

– Avoid hype

– Consider all parts together (Holistic approach)

– Remove deficiencies in foundations

– Implement new solutions

• Useful References

• Holistic Power Supply & Delivery Chain

• Conclusions

3

Useful Public References

• www.iso-ne.com/pubs/whtpprs/smart_grid_report_021709_final.pdf

• EPRI (www.epri.com)– Facilitate the development of a

smart grid interoperability roadmap for NIST (National Institute of Standards and Technology)

– Vision for a Holistic Power Supply and Delivery Chain (#1018587)

– The Green Grid (#1016905)• North American Electric Reliability

Corporation (www.nerc.com)– About NERC -> Understanding the

Grid -> Reliability Concepts / Terminology / Technical Reports

– NASPI (http://www.naspi.org)• Stephen Lee (LinkedIn)

http://www.linkedin.com/in/stylee

IEEE Power and Energy MagazineSept/Oct 2007

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Smart Grid: Hype Cycle

Smart Smart GridGrid

Need an Objective Assessment of the Potential for Smart Transmission and the Path to Achieve it

5

Current State – Power Grid Operations

2-4 Sec scan rates

Limited to info from lines and transformers at substations

MW, MVAR, KV breaker status

2

3

4

5

7

6

1

8

9

1011

12 13

14

15

1617

2

3

4

5

7

6

1

8

9

1011

12 13

14

15

1617

Limited Grid Visibility

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Smart Transmission State – Power Grid Operations

750 +282j

250 +84j

100 +62j

20 + 8j

276 + 120j

130 + 8j

300 + 100j

750 + 262j 440

+ 200j

120 + 11j

350 + 150j

227 + 420j 704 + 308j

2

3

4

5

7

6

1

8

9

1011

12 13

14

15

1617

176 +88j

Higher speed scan rates

Allows more frequent analysis of system state

Enhanced Grid Visibility

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End-uses & DR

Distribution SystemTransmission System

Energy Storage

Fuel Supply System

Fuel Source/Storage

Power Plants

Renewable Plants

Data CommunicationData Communication

Wide Area ControlWide Area Control

Sensors

Controllers

ZIP

M

Dynamic Load ModelsDynamic Power Plant Models

End-to-End Power Delivery Chain Operation & Planning

Monitoring, Modeling, Analysis, Coordination & ControlMonitoring, Modeling, Analysis, Coordination & Control

8

North America Electricity Interconnections

9

Independent System Operators / Regional Transmission Operators (ISO/RTO)

10

North America Electricity Balancing Authorities

11

New Challenges for a Smart Grid

• Need to integrate:

– Large-scale stochastic (uncertain) renewable generation

– Electric energy storage

– Distributed generation

– Plug-in hybrid electric vehicles

– Demand response (smart meters)

• Need to deploy and integrate:

– New Synchronized measurement technologies

– New sensors

– New System Integrity Protection Schemes (SIPS)

12

Foundations Need Strengthening

• End-to-End Situational Awareness• Alarm Management and Real-Time Root-

Cause Diagnosis• Dynamic Models of all Generators and

Loads

• Faster System Restoration• System Integrity Protection Schemes

– Faster reflex actions on wide-area problems

– Measurement-based safety nets to prevent cascading blackouts, e.g., load shedding, islanding/separation, damping

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Why Accurate Models of Loads (Electricity Consumption) and Generators Are Needed?

• Inadequacy of current model data– Inaccurate voltage recovery

simulation after disturbances– Uncertainty about generator

reactive power capabilities• Implications

– Uncertainty about the stability margin of the power grid

– Hidden risk of cascading blackouts, or

– Under utilization of available transmission capacity for greater economic benefits

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 20

0.2

0.4

0.6

0.8

1

Time (seconds)

Vol

tage

(pu

)

Hassayampa 500 kV

MeasuredSimulated H=0.3Simulated H=0.03

Simulated H=0.05Simulated H=0.1Simulated H=0.2Simulated H =0.5

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Major Power System Disturbances

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Duration in Hours

Lo

ad

Lo

st in

GW

1 - 2003 NE

2 - 1965 NE

3 - 1977 NYC

4 - 1982 WSCC 5 - 1996 WSCC

6 - 1996 WSCC

7 - 1998 MW

Restoration Objectives: ▪ Minimize Duration of Outages ▪ Minimized Unserved Loads ▪ Avoid Equipment Danage

Source: NSF/EPRI Workshop on Understanding and Preventing Cascading Failures in Power Systems, Oct 28, 2005.

Effective System Restoration Can Reduce The Societal Impact Of Widespread Blackouts

Extensive (magnitude & duration) blackouts cost Billions of $ to the economy

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New Solutions Are Needed

• Optimal end-to-end commitment and dispatch by ISO/RTO as backstop for system reliability

• Virtual Service Aggregators serving as Energy Balancing Authorities– Dispatch and control stochastic renewable generation– Dispatch and control (and own?) large scale energy storage

plants– Manage demand response proactively– Manage smart electric vehicle charging

• “Virtual” Vertically Integrated Utilities– Own/operate Generation/renewable/storage, some transmission,

& Virtual Service Aggregator– Interstate ownership and operation (overcome NIMBY-ism)

• National/Continental Backbone Transmission Grid– Holistic transmission planning– Virtual RTO– Transmission toll collection system

http://www.energypulse.net/centers/author.cfm?at_id=259

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Potential Role of the Virtual Service Aggregator (Virtual Vertically Integrated Utility)

TraditionalCentral StationPower Plants

TraditionalCentral StationPower Plants

Large-ScaleRenewableResources

Large-ScaleRenewableResources

Large-ScaleEnergyStorage

Large-ScaleEnergyStorage

TransmissionGrid

TransmissionGrid

Real RegionalControl Center

Real RegionalControl Center

VirtualService

Aggregator

VirtualService

Aggregator

End Usesand

DistributedResources

End Usesand

DistributedResources

FinancialSettlement ofNet Difference

Power Flow

FinancialTransaction

LoadsLoads

PHEVsPHEVs

DistributedGeneration& Storage

DistributedGeneration& Storage

S

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Conclusions

• Urgent Need to Make the Bulk Power System Really Smart

• Failure to Make this a High Priority would Jeopardize the Modernization of the Electric Power System

• Key Messages:

– Avoid hype

– Consider all parts together (Holistic approach)

– Remove deficiencies in foundations

– Implement new solutions

THANK YOU!slee@epri.com