Streamlined Method
for Determining
Distribution System
Hosting Capacity
Matthew Rylander
EPRI
April 20, 2015
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Overview
Streamlined Method to Analyze Feeder Hosting
Capacity for Distributed Generation
–Why do we need it?
–How does it work?
2
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Why do we need a Streamlined Method?
PV Growth
 U.S. Annual PV Additions
3
Growth fueled by falling economics, Renewable Portfolio
Standards (RPS), financing schemes, net energy metering,
greenhouse gas (GHG) emissions reduction initiatives
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Why do we need a Streamlined Method?
 Feeders
4
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Analysis
Why do we need a Streamlined Method?
 Feeders
 Issues
Voltage
Protection
Impact
Loading
Control
Total DER Penetration
5
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Analysis
Why do we need a Streamlined Method?
 Feeders
 Issues
 Scenarios
 Hosting Capacity
Impact
Below
Threshold
Analysis
Impact
Depends
Impact
Above
Threshold
Impact
Uncontrolled
DER Deployment
Optimal DER
Deployment
Impact Threshold
Total DER Penetration
6
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Why do we need a Streamlined Method?
 Feeders
 Issues
 Scenarios
 Hosting Capacity
Impact
Below
Threshold
Impact
Depends
Analysis
Impact
Above
Threshold
Feeders with
Similar
Characteristics
7
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Why do we need a Streamlined Method?
Screens
 Load Screens
3.5
Minimum Hosting Capacity
15% of Maximum Load
3
2.5
MW
2
1.5
1
0.5
0
J1 R1 R2 R3 R4 T1 T2 G1 G2 G3 P1 P2 P3 P4 P5 D1 D2 D3
Feeder
Too Conservative
Not Conservative Enough
8
© 2015 Electric Power Research Institute, Inc. All rights reserved.
What type of Streamlined Method is needed?
Granular
Repeatable
Scalable
Transparent
Proven
Available
• Capture unique feeder-specific responses
• As distribution feeders change
• System-wide assessment
• Clear and open methods for analysis
• Validated techniques
• Utilize readily available utility data and tools
EPRI’s Streamlined Hosting Capacity
9
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Evolution of Streamlined Hosting Capacity
Streamlined Hosting Capacity
Detailed Hosting
Capacity
– Analysis performed in the Utility’s
distribution software tool
– Minutes compared to weeks
– Entire system analyzed
Correlation
Assessment
Streamlined Hosting
Capacity
10
© 2015 Electric Power Research Institute, Inc. All rights reserved.
What does the Streamlined Method look like?
Interface with utility model in the utility platform to
attain:
– Voltage Profiles
– Currents/Loading
– Impedances
– Topology
Streamlined Hosting Capacity currently performed
external to commercial software
11
© 2015 Electric Power Research Institute, Inc. All rights reserved.
How does the Streamlined Method work on a feeder?
 Single System
Hosting Capacity
Substation
Resistance from Source
12
© 2015 Electric Power Research Institute, Inc. All rights reserved.
How does the Streamlined Method work on a feeder?
 Multiple Systems and Topology
Hosting Capacity
Substation
Must Account for Feeder
Topology
Resistance from Source
13
© 2015 Electric Power Research Institute, Inc. All rights reserved.
How does the Streamlined Method work on a feeder?
 Distributed Systems
Hosting Capacity
Substation
Resistance from Source
14
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Feeder-Level Hosting Capacity
Hosting Capacity
Impact
Below
Threshold
Optimal PV
Deployment
Impact
Depends
Impact
Above
Threshold
Hosting
Capacity
Range
NonOptimal PV
Deployment
Max HC
Min HC
Resistance from Source
15
© 2015 Electric Power Research Institute, Inc. All rights reserved.
What does Feeder-Level hosting capacity look like?
16
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Outcomes of the Streamlined Hosting Capacity Analysis
 This is not a replacement for
detailed studies but it does provide
guidance to when detailed studies
are necessary
 Questions Answered
– Where is the “optimal” location for
DER?
– How much aggregate DER can a
feeder host?
– When my feeder changes, how is
hosting capacity impacted?
– What is the aggregate level of DER
that can be accommodated at the
substation level?
– What amount of DER can be
accommodated across my entire
system?
– What are the range of issues for
accommodating DER across the
entire distribution system?
Substation Level
=
Overvoltage
Thermal
Loading
Voltage
Fluctuations
Feeder Level
Feeder Level
Relay
Coordination
Feeder Level
17
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Relay
Desensitization
Final Thoughts…
 PV is coming
 Need efficient methods to plan for it
 Methods will continue to evolve
– Consideration of existing distributed energy resources
– Inclusion of other types of distributed energy resources
– Advanced inverter capabilities
18
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Together…Shaping the Future of Electricity
19
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Minimum Hosting Capacity Comparison
Multiple Issues for One Feeder
Utility Class DER
Residential/Commercial DER
20
© 2015 Electric Power Research Institute, Inc. All rights reserved.
Minimum Hosting Capacity Comparison
One Issue for Multiple Feeders
Utility Class DER
Residential/Commercial DER
Preliminary Findings
+ Effectively identifies when lower hosting capacity values are found
+ Close match at low hosting capacity
+ More conservative result at higher hosting capacity
+ Comparable results for all potential issues
+ Effective for small-scale (customer-based) and large-scale (utility-sized) systems
21
© 2015 Electric Power Research Institute, Inc. All rights reserved.
What about Distributed Residential/Commercial PV?
Current
Distribution
1.5 MW
DER
Distribution
1.5 MW
1.0 MW
1.5 MW
0.5 MW
1.0 MW
0.5 MW
1.5 MW
DER Center 1 DER Center 2 DER Center 3
Location from Substation
1.5 MW
1.5 MW
Impact
Impact Threshold
1.0 MW
1.5 MW
0.5 MW
Hosting Capacity
Location from Substation
DER Center 1 DER Center 2 DER Center 3
Location from Substation
Location from Substation
Notes
+ The streamlined method is not a stochastic analysis but the impacts from different possible DER deployments on the
feeder are incorporated under the thousands of analyzed DER distributions.
22+ The impact is not typically linear. Only illustrated here for visualization purposes.
© 2015 Electric Power Research Institute, Inc. All rights reserved.
+ Impact threshold for each issue is adjustable.
Potential
Issues
Conservative
Issues
Optimistic
No Issues
Realistic
Every Potential Issue has a Hosting
Capacity that also Depends on…
Power
Extreme Boundary of Possible
DER Distribution Characteristics
Hosting Capacity with
Lateral Diversity
More Probable Boundary
of Possible DER
Distribution
Characteristics
Hosting
Capacity
Location from Substation
Hosting
Capacity
Range
Notes
+ Extreme bounds only possible with large pockets of DER either at the feeder head or end.
+ Probable bounds incorporate randomness in DER location across feeder.
23
+ Lateral diversity indicates higher hosting capacity
on DER
across parallel laterals on the feeder.
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Power Research
Institute,distributed
Inc. All rights reserved.