1. Plans for High DER Penetrations: With Examples from PG&E’s Distribution Resources Plan
Distribution Systems and Planning Training
for NASUCA 2018 Mid-Year Meeting, June 24-27, 2018

2. PG&E’s Distribution Resources Plan 2015
PG&E’s traditional distribution planning process includes:
Forecasting load and peak demand
Power flow modeling to simulate performance to determine needs
Identifying and developing capacity additions to meet needs
The goal of the DRP is to integrate DERs into the distribution planning process
California AB 327requires the 3 major utilities to file DRP
Determine system capacity to integrate DERs
Determine methodology for locational values of DERs
Forecast growth of DERs and demonstrate projects
Identify issues surrounding safety, data, and tariffs that can help or hinder DER development
PG&E, DRP Webinar, 2015

3. PG&E’s Distribution Resources Plan 2015
2. Integration Capacity
3. Locational benefits and costs
1. DER Growth Scenarios
4. Demonstrations
CPUC asked for these four pieces in the DRP
Adapted from PG&E, DRP Webinar, 2015

4. Ten DERs were examined
PG&E, DRP Webinar, 2015

5. Three scenarios were created
1. DER Growth Scenarios
Three scenarios were created
These Scenarios looked out ten years
PG&E, DRP Webinar, 2015

6. DERs may significantly impact peak load
1. DER Growth Scenarios
DERs may significantly impact peak load
Let’s turn to the key findings of their growth scenarios
This shows how many MW they expect DER to contribute at their system peak hour in Aug of 4-5pm
By 2025 they expect nearly 7 GW in their BAU scenario and 12 GW in their very high growth scenario
Just for comparison their peak load (net of BTM DG) is 21-22GW so this is like half of system peak that is served by DERs
PG&E, DRP Webinar, 2015

7. Energy efficiency and solar have greatest impact on peak load
1. DER Growth Scenarios
Energy efficiency and solar have greatest impact on peak load
A second finding is that of the 10 DERs examined, the ones that had the biggest impact at peak load hour were energy efficiency and PV.
PG&E, DRP Webinar, 2015

8. Impacts depend on DER characteristics and local load profiles
1. DER Growth Scenarios
Impacts depend on DER characteristics and local load profiles
PG&E, DRP Webinar, 2015

9. Other findings from growth scenarios
1. DER Growth Scenarios
Other findings from growth scenarios
DERs likely to cluster
To estimate DERs, we need to understand load and adoption patterns
Past behavior may not be indicative of future behavior
PG&E, DRP Webinar, 2015

10. Hosting capacity analysis - granularity
2. Integration Capacity Analysis
Hosting capacity analysis - granularity
PG&E has over 3000 feeders
Each feeder is broken down into line sections which are in between line devices like voltage regulators or protection devices.
Sections are further broken down into segments in between nodes
On average each feeder has 34 sections
PG&E, DRP Webinar, 2015

11. What tools did PG&E use? PG&E, DRP Webinar, 2015
2. Integration Capacity Analysis
What tools did PG&E use?
PG&E recently upgraded its planning tools to handle increased DER penetrations
For load and generation hourly profiles, they use LoadSEER (as does SDG&E)
If you have a lot of SCADA devices and monitoring points, using that data may be best
If you have a lot of AMI data then that data may be aggregated and used
PG&E used SCADA and AMI and other customer info to create profiles
For the load flow analysis, PG&E, similar to SCE, used CYME.
PG&E, DRP Webinar, 2015

12. Which power system criteria did PG&E evaluate?
2. Integration Capacity Analysis
Which power system criteria did PG&E evaluate?
Note that in the more recent hosting capacity analysis that PG&E undertook for their Demo A project, the compared their streamlined or simplified approach to the detailed or iterative method that SCE/SDG&E use
They examined steady state V, V regulator impacts and V variations
PG&E, DRP Webinar, 2015

13. PG&E analyzed 102,000 line sections within >3000 circuits
2. Integration Capacity Analysis
PG&E analyzed 102,000 line sections within >3000 circuits
Note that these utilities are just modeling the primaries, not the secondaries. I don’t’ know of any hosting capacity that models the secondaries.
PG&E focused on large centralized DER impacts
PG&E’s streamlined method doesn’t directly place DER in the model but rather uses an algorithm to consider distribution of DER placement
PG&E, DRP Webinar, 2015

14. PG&E map of hosting capacity
2. Integration Capacity Analysis
PG&E map of hosting capacity
From PG&E DRP Web Tool, 2016

15. PG&E map of hosting capacity
2. Integration Capacity Analysis
PG&E map of hosting capacity
Provide capacities for 10 different DER types/models
“Uniform Generation” and “Uniform Load” types can be used for DER with constant or unspecified profiles
The uniform profiles can also be used to understand storage charge and discharge capabilities with unconstrained operation times
Substation (Bank and Feeder) limits are provided to inform customers that intend to interconnect to multiple line sections on a Feeder and/or Bank
Line Section Level results provide a range indicating different capacities based on where interconnection on line section
Many line section results have little / no difference between the two values because the granularity achieved is quite detailed
You can interconnect up the minimal impact level
This is a work in progress. Since the original plans, CPUC asked IOU’s to have 6 maps: PV, uniform generation, and uniform load
To be run with and without reverse power flow allowed at SCADA devices
From PG&E DRP Web Tool, 2016

16. Hosting capacity analysis for Hydro/Biogas in PG&E
2. Integration Capacity Analysis
Hosting capacity analysis for Hydro/Biogas in PG&E
Here’s an example of aggregated hosting capacity results in PG&E for hydro, biogas and other DER that has constant full output
At the substation transformer bank level, generally the bigger banks can host more DER
At the feeder level, generally the higher V lines can host more
And when you get down to the line section level, generally, the devices that are clos to the head of the substation have higher hosting capacity than those at the end of the line
PG&E, DRP Webinar, 2015

17. Hosting capacity analysis for Storage in PG&E
2. Integration Capacity Analysis
Hosting capacity analysis for Storage in PG&E
PG&E, DRP Webinar, 2015

18. Start with existing tools and add granularity
3. Locational net benefits
Start with existing tools and add granularity
The 3rd part of the plan is the LNBA
PG&E started with E3’s DERAC calculator which is a spreadsheet valuation tool that includes avoided energy, losses, capacity, emissions, RECs and T&D capacity deferrals
They then added granularity to that on the distribution system – distribution capacity split from tx; voltage and power quality; reliability; renewable integration costs
PG&E, DRP Webinar, 2015

19. Locational value 3. Locational net benefits PG&E, DRP Webinar, 2015
One thing they noted is that distribution upgrade deferral isn’t as easy as you might think. I mentioned in the last talk about lining up these 4 criteria. Also there’s a good part of the dx system that isn’t seeing the type of load growth that would drive needs for upgrades that could be deferred.
And then, if you were considering DPV to provide deferrals of upgrades, you'd have to think about the ability to DPV to reliable provide power during feeder peak. APS and EPRI do have a project examining this now but this would be hard because there’s no geographic diversity to mitigate the cloud problem. Reliability is all about statistics so if statically you’re in a place with no clouds at peak, maybe that could work.
PG&E, DRP Webinar, 2015

20. 3. Locational net benefits
Locational net benefits analysis for Demo B in Southern California Edison
The IOUs have been working with E3 to develop a spreadsheet based LNBA tool that takes the DERAC tool and adds in these more granular components. One piece of this is that T&D deferral module that looks at how long you might be able to defer an upgrade and how the time value of money allows you save money, like what Andrew showed. The Other pieces examine voltage support, reliability by deferring back-tie equipment, resiliency through a microgrid
the LNBA tool is hoped to allow DER developers to estimate the deferral value of a DER solution by inputting location-specific values to the system level values
Locations would be categorized or ranked based on the relative benefits that DERs are likely to provide
What the tool does not yet do is “proactively identify those [DER] values across the entire distribution and transmission system,” They have to be input.
The IOUs keep the actual deferral values confidential
In their planning processes, they select deferral opportunities for a solicitation and publish them online
 the LNBA tool is not ready for DER sourcing or compensation
Rather than being based on a utility’s avoided costs, procurement should be based on an estimate of what it would take to get additional DERs deployed.

21. Medium cost project 3. Locational net benefits
As an example in SCE’s web-based LNBA map you can click on a feeder and it will tell you what kind of distribution upgrade you could possibly defer.
Here, it’s a switched capacitor project. 2$$ says it’s a medium cost project

22. Resources
Consumers Energy’s Electric Distribution Infrastructure Investment Plan, 8/1/17, Filing U
Unitil’s Grid Modernization Plan, 8/19/15, under Docket
PG&E Distributed Resources Plan, 2015,

23. Acronym definition ADMS Advanced Distribution Management System
AMF Advanced Metering Functionality
AMI Advanced Metering Infrastructure
CVR Conservation Voltage Reduction
DERMS Distributed Energy Resource Management System
FAN Field Area Network
FLISR Fault Location, Isolation, and Service Restoration
IEPR Integrated Energy Policy Report
NWA Non-wires Alternatives
OMS Outage Management System
SAIDI/SAIFI System Average interruption Duration/Frequency Index
SCADA Supervisory Control and Data Acquisition
TVR Time-varying Rates
VVO Volt VAR Optimization

24. Any Questions?
Contact Debbie Lew at