© 2015 Electric Power Research Institute, Inc. All rights reserved.
Jeffrey D. RoarkTechnical Executive, EPRI
EPRIIntegrated Grid
FrameworkTask Force on Energy Supply
NCSL SummitAugust 2, 2015
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The Landscape– Most new generation connecting at grid “edge”
– The “edge” is the distribution system
– Distribution has least amount of utility visibility/control
Distributed Energy Resources (DER)
Combined Heat & Power
Demand Response
Home Energy Management
Rooftop Solar
Electric Vehicles
Large-Scale Solar
Energy Storage
3© 2015 Electric Power Research Institute, Inc. All rights reserved.
Challenges for Utilities– Accommodate disruptive innovations– Improve efficiency– Incorporate demand response– Increase resiliency– The list goes on…
Distributed Energy Resources (DER)
Combined Heat & Power
Demand Response
Home Energy Management
Rooftop Solar
Electric Vehicles
Large-Scale Solar
Energy Storage
4© 2015 Electric Power Research Institute, Inc. All rights reserved.
This Dynamic Power System Requires an End-to-End Integrated Approach
AnIntegrated
Grid
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EPRI’s Integrated Grid Initiative
30020027333002004878
At EPRI.com, search for the complete number: 300200xxxx
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Integrated Grid MethodologyThe Integrated Grid’s benefit-cost framework
contains both bulk system and distribution system elements.
Bulk System Resource Adequacy
Flexibility
Operational Practices & Simulation
Transmission Performance
Transmission Expansion
Distribution System
Hosting Energy
Capacity Reliability
Scenario Definition
DER Adoption
Market Conditions
System Assumptions
Customer or Owner
Cost/Benefits
Societal Costs/Benefits
Benefit/Cost
System Cost
Changes
Transmission System
Performance Studies
DER Scenarios
Resource Adequacy
Existing SystemModel(s)
Load Forecasts
Variability Profiles
Existing Generation
Existing Network Model
Resource Epxansion
LOLE/Reserve Margin & Capacity
Credit
New Resources/Expansion
Plan
Thermal / Voltage Impacts
Operational Simulations
Resource Dispatches
Transmission System
Upgrades
Technology options
Transmission Expansion
Losses
Reliability ImpactsReserve &
Operational Changes
LOLE/Reserve Margin & Capacity
Credit
New Reserve & Operational
Modes
Integrated GridBulk System
Analysis Framework
Costs of new resources
Production Costs & Marginal
Costs
Costs of mitigation/upgrades
Cost of Losses
Cost of Base Case
Cost of Scenario
System Flexibility
Assessment
Flexibility Metrics
Line Type LegendData InputFinal ResultFeed-Forward ResultFeed Back Result
Frequency Impacts
Hosting Capacity PV & Demand
Profiles (See Fig. 5.3)
PQ & Protection Impacts
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Features of the Benefit-Cost Framework
Comprehensive: Can includeany quantifiable impacts from distribution to bulk system, with or without externalities
Flexible: Designed to address a variety of economic questions from a variety of perspectives– Can adopt a utility-planning perspective for guiding decisions, or a broader societal perspective for policy implications
8© 2015 Electric Power Research Institute, Inc. All rights reserved.
EPRI’s Benefit-Cost Framework
SocietalImpacts
Customer Impacts
Bulk System Impacts
Distribution System Impacts
• Net Capital Cost Changes• Net Fuel/O&M Changes(Avoided less Incurred)
• Net Capital Cost Changes• Net O&M Cost Changes(Avoided less Incurred) Change in
Utility Cost (The Utility‐Cost
Function)
• Reduced/Increased Emissions• General Economic Effects
Monetization Protocols
DirectCustomer Benefits
Net Societal Benefits
• Reliability Improvement• Resiliency Improvement• Customer Equipment Cost
Monetization Protocols
Societal Benefits
9© 2015 Electric Power Research Institute, Inc. All rights reserved.
Steps to Apply Cost-Benefit Framework
Formulate Question
Define Scenarios and Assumptions
Evaluate ScenariosUsing Benefit - Cost
Framework
Compare Scenariosand Identify “Best”
OptionThe economic and technical questions for the framework are not pre-configured.
10© 2015 Electric Power Research Institute, Inc. All rights reserved.
EPRI’s Integrated Grid Initiative
30020027333002004878
3002006692
At EPRI.com, search for the complete number: 300200xxxx
11© 2015 Electric Power Research Institute, Inc. All rights reserved.
Capacity and Energy in the Integrated Grid
Are we becoming capacity-inefficient and capacity-scarce while becoming energy-efficient and energy-abundant?
The Capacity and Energy report describes:– How individual resources may contribute differently
to the system’s capacity to deliver energy
– How changing supply and load characteristics make it necessary to distinctly address both energy and capacity on wholesale and retail levels
– The cost of capacity, based on an assessment of cost structures of several U.S. utilities
– Emerging trends in wholesale markets and retail rate structures to value capacity and energy as distinct elements of those structures
– Key research to enable DER to provide both capacity and energy
12© 2015 Electric Power Research Institute, Inc. All rights reserved.
A Week in the Life of a Solar-Powered Home
Receiving power from the grid
Sending power to the grid
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Utilities have high levels of fixed cost to support capacity to supply/ accept energy to/from customers.
Analysis of 10 unique utilities’ cost structures based on FERC Form 1 and EIA data.
Fixed and Variable Cost Composition of Residential Average Bill
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Applications Integrated Grid
Benefit/Cost Framework
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Distribution System is Immense in Scale
Distribution diagrams courtesy of Salt River Project
Typical Distribution Utility
Number
Distribution Service Territory 1
Distribution Planning Area 1’s - 10’s
Distribution Substations 10’s - 100’s
Distribution Feeders 100’s -1000’s
Distribution Transformers 1000s - 1,000,000’s
Distribution Customers 100,000’s - 1,000,000’s
Feeders are the overhead and underground lines that connect to homes and businesses to a substation.
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Hosting Capacity: DER Size and Location
Distribution Systems Respond Uniquely to DER
What matters most? DER technology and Impacts DER size and location Feeder construction and operation
All Impacts Below
Threshold
ImpactDepends
(on size & location)
All Impacts Above
Threshold
Voltage
Protection coordination
Thermal capacity
DER Technology and Impacts
DER Size and Location
Feeder Construction & Operation
(MW)
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Substation
Hosting Capacity:
Sample Results from Integrated Grid Projects
System Hosting Capacity(~ 300 distribution feeders)
Substation-level Hosting Capacity
Feeder-levelHosting Capacity
Initial analysis results from in Integrated Grid study, results preliminary
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Hosting capacity analysis is only the first step…
Accommodation at Penetrations Beyond Hosting Capacity– Voltage Limits
– Protection Issues
Thermal Capacity Analysis– Deferral of upgrades
– Loss of life
Energy Analysis– Distribution losses
– Energy consumption
Cost/Benefit Analysis
Integrated Approach
Voltage
ProtectionCapacity
Energy Reliability
Watts
Impedance
Load Only
Load and PV
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Energy Losses
Energy
Time
unserved energy
energy exceedingnormal
Curren
t
Impedance
relay desensitization
volta
ge
time
limit
unacceptableovervoltage
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Key Insights• Each feeder has unique technical impact from various levels of PV.
• Utility planning practices impact the potential to defer transformer and/or conductor capacity.
• PV reduces line losses, but consumption increases when voltage increases. There is usually a net reduction of losses.
• “Smart Inverters” (a component of PV systems) can obviate the need for some upgrades, but upgrades are often needed at high penetrations.
• At high penetrations, upgrades may be necessary to maintain protection coordination and voltage control.
20© 2015 Electric Power Research Institute, Inc. All rights reserved.
Questions?
Together…Shaping the Future of Electricity
Jeffrey D. RoarkTechnical ExecutiveElectric Power Research Institute3379 Lakewind WayAlpharetta, GA [email protected]
21© 2015 Electric Power Research Institute, Inc. All rights reserved.
Jeffrey D. Roark, EPRI
34 years experience in regulated, unregulated, and government utilities– transmission and generation system planning,– strategic planning– bulk power contracts– power market analysis– wholesale deal structuring– trading and marketing research– regulatory analysis (as both regulator and regulated)
With EPRI since 2011, responsible for cost/benefit analysis in many projects within PDU
BEE, MSEE Auburn UniversityMBA, University of Alabama at Birmingham
