pev consumer behavior study plug in 2012 haddow v3 panel

Designing PEV Infrastructure

Do PEV TOU Rates Impact PEV Charging Time Decisions?

Gregory W. Haddow

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CREATE AN EXCELLENT CUSTOMER EXPERIENCE AND SUPPORT THE GROWTH OF ELECTRIC TRANSPORTATION WHILE ENSURING THE SAFE, RELIABLE & EFFICIENT INTEGRATION OF PEV LOADS WITH THE GRID

Charging Technology & Infrastructure

Widespread & convenient

Charging Pricing

Attractive to charge off-peak

Utility System Integration

Efficient & smart

Market Development

Educate & support

SDG&E Goals

EV Rate Participation & Ownership are Growing

Jan11 Feb11

Mar11 Apr11 May11

Jun11 Jul11 Aug11

Sep11

Oct11 Nov11

Dec11

Jan12 Feb12

Mar12 Apr12 May12

Jun120

200

400

600

800

1,000

1,200

1,400

1,600

1,800

Total Vehicles PEV Rate customers Experimental Rate Customers

~1,600 Total PEVs through June '12(need Randy's GM #s)

394 Experimental Rate Customers (Submetered PEV usage)

701 PEV Rate Customers(Premises Metered and/or Submetered)

WHAT DRIVES CHARGING TIME DECISIONS?

PEV RATES & TECHNOLOGY STUDY – CPUC APPROVED EXPERIMENTAL PEV RATES FOR EV PROJECT & NISSAN DEPLOYMENT

AM PM• Price – Fuel Savings?

Low Super Off-peak rates• Technology & Information –

“Set & Forget”?

On-board Leaf technology • Convenience & Lifestyle –

Do Travel Needs Rule?

Schedule

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RESEARCH ADVISORY PANEL • San Diego Gas & Electric

• UC Davis, Tom Turrentine, PHEV Research Center

• EPRI, Bernie Neenan, Electric Transportation Program

• University of San Diego-EPIC, Scott Anders & Nilmini Silva-Send

• UC San Diego, Professor Graff Zivin & Ben Gilbert

• CEC, Phil Misemer

• U.S. EPA, Zoltan Jung

• CCSE, Mike Ferry

• SCE, Russ Garwacki

• SMUD, Bill Boyce

• EV Project / ECOtality, Don Karner

• Coulomb Technologies, Richard Lowenthal

• Boulder Energy Group, Bill Le Blanc

• EEI, Rick Tempchin

• CPUC Staff

STUDY OBJECTIVE

To examine PEV consumer charging time preferences, use of technology, and other relevant factors in a controlled study of CPUC-approved time-differentiated rates coincident with the EV Project and Nissan Leaf launch in San Diego.

Working Hypotheses•Time variant pricing and technology use will influence consumer charging behavior•Greater price variations will drive more charging activity to off-peak periods •Enabling technology will facilitate charging behavior that is convenient and economic to the consumer

STUDY DESIGN

Independent Variable

Leaf Customers Randomly Assigned to 3 Time Variant Priced RatesEach rate differing in super off-peak to on-peak price spread

Dependent Variable

Time-of-use Charging

Ratio of on-peak charging kWh to off-peak and super off-peak charging kWh per day

Conditioning Variables• Use of Enabling Technology• Driver Profile• Use of Charging Facilities

PEV EXPERIMENTAL RATES – SUMMERC

ents

per

kW

h

On-peakNoon to 8pm

Off-peak8pm to midnight

5am to Noon

Super Off-peakMidnight to 5am

0

5

10

15

20

25

30

35

40

EV-TOU Rate 2 Rate 3

SEPARATE PEV METERING

House MeterSDG&E determines location of the separate PEV meter (in series), with flexibility regarding the disconnect breaker

Garage Panel

EVSE

PEV Meter

EV TOU Rate is Effective Regardless of Price

On-Peak Off-Peak Super Off-Peak0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

9%13%

78%

7%11%

82%

7%10%

83%

EPEV-L (N=110) EPEV-M (N=146) EPEV-H (N=138)

% o

f T

ota

l Co

nsu

mp

tion

Three Experimental EV Rate Customer Groups

Super Off-Peak Charging at Homeis Encouraged by TOU rates

7%

11%

82%

On-Peak Off-Peak Super Off-Peak

• Usage: 3 experimental PEV rate groups kWh usage combined

• Data: January 2011 to June 2012

• Super Off-Peak: Midnight to 5 am

• Off-Peak: 5 am to Noon & 8 pm to Midnight

• On-Peak: Noon to 8 pm

Charging Behavior Similar Across the 3 Experimental Rate Groups

Separately metered data isolates the charging use

Super Off-peak usage Midnight to 5 am indicates the use of EVSE or PEV timers

Hour 12 = NoonHour 24 = Midnight

Slightly Less Charging on Weekends

Indicates a routine driving & charging pattern, regardless of day of week

TOU Rates Influence PEV Charging

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TOU rates encourage off-peak charging vs. a flat rate

Source: INL http://avt.inl.gov/pdf/EVProj/EVProjInfrastructureQ42011.pdf

Nashville Electric Svc, TN• 260 residential EVSE• Charge: $13.43 / month• Summer: $0.0936 / kWh• Winter: $0.0898 / kWh $

SDG&E, CA• 539 residential EVSE• TOU rates• Super off-peak:

midnight to 5am

PEV Driving Maturation in ~ 6 months

“Charge Month” is the month after initial charge, regardless of calendar month of the PEV purchase

Line denotes 3 month moving average

IMPLICATIONS

•Too soon to tell if charging patterns are stable •Is fueling cost so low that charging will shift to off peak and on-peak periods over time? •It doesn’t take much pricing incentive to change behavior – 1 to 2 pricing difference between super off-peak and on-peak as effective as the 1 to 6 differential•Convenience technology works – implies smart grid technology must be simple “set and forget” in nature•If PEV rate structures becomes more complex (e.g., weekday-weekend, summer-winter, tiers), simpler technologies may be less effective

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Designing PEV InfrastructureGregory W. Haddow

GHaddow@SempraUtilities.com

SDGE.COM/EV

EV@SDGE.COM