PG&E conducted a smart grid pilot project to test volt VAR optimization (VVO) technology on distribution circuits. The objectives were to enhance grid monitoring and control, achieve grid efficiencies from conservation voltage reduction, and accommodate growing distributed generation. Two VVO vendors were tested both in a lab and in field trials on 14 feeders. Preliminary results found energy savings of 0.1-2.2% depending on the season. Lessons learned included the need to address reverse power flows from high distributed generation and properly screen feeders for existing voltage issues. Future work involves exploring the value of controlling smart inverters through VVO and conducting additional field trials.

1. Smart Grid Pilot Projects
Volt VAR Optimization
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Volt VAR Optimization Smart
Grid Pilot at PG&E
EPRI / Sandia PV Systems Symposium
Rustom Dessai, PE – PG&E Emerging Grid Technologies
May 10, 2016

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PG&E Smart Grid VVO Background
Objective - evaluate VVO’s ability to:
1. Enhance grid monitoring & control
2. Grid efficiencies and Conservation Voltage Reduction
3. Accommodate growing distributed generation
Scope – Lab Test (Phase 1) then Field Trial (Phase 2) on 14 feeders
• Pilot two competing vendors
• Extensive testing completed at PG&E ATS Facility
• Varying DG penetration (ranging from 2% – 35%: nameplate / peak)
Preliminary* results to date from 12 feeders:
• Summer 2015: 0.1% energy savings
• Fall 2015: 2.2% energy savings
• Cumulative Energy Reduction: 1.5%
• Cumulative Average CVRf: 0.9
* Results will be refined through course of pilot as new data and analysis methods are introduced

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VVO Technology Overview
• VVO incorporates sensing, communications and computing to more tightly control voltage
delivered to customers
• Reducing voltage drives energy efficiency through Conservation Voltage Reduction (CVR) –
reducing delivered voltage reduces energy consumption without sacrificing device/appliance
performance & customer satisfaction
• Has the promise to deliver:
• 1-2% reduction in energy demand and consumption
• Improved voltage control on circuits with high DG penetration
120V
126V
114V
Line CapacitorLine RegulatorSubstation LTC Customer
Load
Distributed
Generation
Original
Voltage
Voltage
with VVO

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Vendor Selection for the VVO Pilot
PG&E’s Key Requirements for VVO
• Must function with a balanced model (rather than unbalanced w/ phasing)
• Must minimize initial configuration and maintenance, preferably by leveraging an
existing network model (preferably GIS or DMS)  maintaining an additional network
model and manual configuration/maintenance processes are a last resort
• Must support increased distributed generation penetration
• Must utilize or integrate with existing operator interfaces (either DMS, SCADA or PI)
Strategies to Guide VVO Vendor Selection
• Leverage existing assets
• Maximize customer benefits
• Manage future grid complexity
• Provide path to DMS/EMS integration
• Minimize Total Cost of Ownership
PG&E Pilot VVO Vendors1 Selected through RFP, Benchmarking, and Demos
• Measurement based systems – not requiring unbalanced models
• Different strategies: Secondary (AMI) vs Primary / Set point vs tap control
• Perceived ability to handle increasing grid complexity relative to field
• Existing installations at other utilities
(1) PG&E will reassess the marketplace when choosing a vendor for a wide-scale deployment of VVO

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PG&E DTY Testing Facility
UIQ System
Distribution Test Yard
Meter Simulator AMI Head End
Test VVO SCADA
Network Model
Meter Farm
PG&E utilized the distribution test yard (DTY) to simulate circuit responses to VVO
operation, allowing evaluation of vendor solution performance prior to field
deployment.

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DG Penetration Increases on VVO Circuits: 2013 - 2016
• Original VVO feeder selection analysis done near end of 2013
• Observed significant increases in DG penetration on VVO feeders in short span (<3
years) of pilot
0%
5%
10%
15%
20%
25%
30%
35%
40%
A-1101 A-1102 A-1103 P-2101 P-2102 P-2103 B-1114 B-1115 B-1116 W-2104 W-2105 W-2106 D-1102 D-1104
VVO Feeder DG Penetration Increases
DG / Peak Load 2013 DG / Peak Load 2016

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Reverse power seen at feeder and regulators
Feeder Head Regulator

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Reverse Power VVO Vendor Strategy Progression through Pilot
No strategy Disable VVO
Ride-through
reverse power for
co-gen regs,
disable otherwise
Vendors not allowed
out of test phase
Caused certain
systems to trip
regularly around
midday
Works well for
PG&E’s VVO circuits,
no issues so far

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VVO’s Effect on Woodward 2106 (has high DG Penetration > 25% of load)
No issues with 2 On days, some issues with 3 Off days
VVO
On
VVO
Off
VVO
On
VVO
Off
VVO
Off
• VVO team will continue studying VVO’s impact on voltage in presence of PV
• Currently testing one VVO vendor’s strategy to use irradiance forecast to hedge
voltage against PV variability

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• Found existing voltage unbalance on feeders during summer severely limited
VVO functionality
• Analysis of frequent AMI voltage readings can help weed out feeders that may
have existing issues with voltage or voltage unbalance
• As part of the VVO pilot, PG&E enabled 15 min / hourly voltage reads on 1
million meters to analyze how this data may inform VVO feeder selection
Lessons Learned: Feeder Screening
Aug 25 Aug 26 Aug 27 Aug 28
VVO
On
VVO
Disables
VVO
On
VVO
Disables
126
120
114
Sept 29 Sept 30 Oct 1 Oct 2
126
120
114
VVO
Off
VVO
On
VVO
Off
VVO
On
Summer2015Fall2015

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Lessons Learned: Value from Proactive Issue Identification and Resolution
• Configured Tableau and PI screens as tools to monitor AMI voltages and SCADA
data to identify issues proactively and find resolutions
• Almost all issues related to secondary problems, but also used to adjust existing
settings on field equipment, and to confirm VVO settings
T-man replaces service drop to customer and resolves problem before customer notices issue

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Exploring value of Smart Inverters for VVO
Modeling (complete)
• How can VVO control of Smart Inverters improve VVO performance?
• What value could VVO extract from “VARs at night”?
Lab Testing (in progress)
• What “VVO friendly” power factor and Volt-Var settings deliver safe
“no fight” conditions in the field
Field Trial (later in 2016)
• Collaborate with 3rd party installers to have Smart Inverters installed
in Q2 2016, adjust power factor and Volt-Var settings to improve VVO
benefits

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Large DG
Dinuba Sub
Complex with concentrated DG
• > 100 circuit miles
• 5 line voltage regulators
• 23% DG penetration1
• Three large DGs: 2 x 1 MW, 1 x 0.7 MW
VVO Go Live in Jan 2016 drove interest in
predicting performance
(1) Measured as DG capacity / feeder peak load. At time study began,
additional DG connection has raised penetration to 34% as of January 2016
Dinuba
Dinuba 1104 studied due to challenging voltage control conditions

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Case 2: Traditional VVO
Case 3: VVO plus SI P.F. control
Charts below show comparison of VVO savings metrics Case 1
(No VVO) at varying DG penetration levels
VVO control of SI can deliver line loss reduction at low DG penetration,
and energy delivery savings at higher penetrations
0%
2%
4%
6%
8%
10%
23% 47% 70% 94%
DG Penetration
Daytime
(8 am – 6 pm)
VARs at Night
0%
2%
4%
6%
8%
10%
23% 45% 68% 91%
0%
3%
6%
9%
12%
15%
23% 47% 70% 94%
0%
3%
6%
9%
12%
15%
23% 45% 68% 91%
Energy
Delivery
Savings*
Line Loss
Reduction*
*Results should be deemed as a general guideline regarding potential VVO benefits. It is recommended that further
analyses be conducted for a larger sample of feeders with varying topologies, voltage levels, customer densities, customer
types, etc.
NOTE: Larger % savings
does not necessarily
correlate to larger
magnitude of energy
delivered savings because
overall energy delivered
decreases in magnitude as
penetration increases.

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DG as Part of VVO – Technical Analysis Results
Case 1: No VVO, PV-DG operates at unity power factor
Case 2: VVO controls LTC, Regs, and Caps, PV-DG operates at unity power factor
Case 3: VVO controls LTC, Regs, Caps, and DG smart inverter power factor (0.95 lead, unity, or 0.95 lag)
*Results should be deemed as a general guideline regarding potential VVO benefits. It is recommended that further
analyses be conducted for a larger sample of feeders with varying topologies, voltage levels, customer densities, customer
types, etc.

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VVO Pilot Smart Inverter Field Trial
• Adjust Smart Inverter P.F. and Volt-VAR settings to evaluate impact to VVO
performance
Follow technology and regulatory
development to automate use of
Smart Inverters
• DERMS EPIC Technology Demonstration
in late 2016
• Follow ADMS / VVO / DERMS
technology developments
• California Distributed Resources Plan –
locational value of Smart Inverters?
GRID of
THINGS
Next Steps for SI

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Post-Pilot Deployment
• 2017-2019 GRC proposed $84M deployment on 228 feeders (7% of
PG&E’s system)
• Presently forecasting a benefit-cost ratio of 1.2 – 2.0, and will be
updating forecast in May
• Plan dependent on PG&E’s SCADA and DMS plans – Deployment of VVO
would be tightly integrated with DMS enabling automated configurations
and reconfigurations
• PG&E is not tied to piloted vendors, and will reassess the VVO vendor
market place for deployment vendor

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Questions?
Questions?